View source for Pathloss 4.0 revision history

== Pathloss 4.0 - Build date March 4, 2014 ==

Space diversity using the IF combining configuration using the total time below level calculation method.

The effective space diversity improvement factor is calculated from the unprotected availability and the protected availability.

The protected availability numbers are correct; however, the effective space diversity improvement was incorrect.


== Pathloss 4.0 - Build date February 7, 2012 ==

Filter improvement calculations in an interference analysis. Modifications made to accommodate very narrow band (.1 MHz) interfering transmitters into a wide band receiver

== Pathloss 4.0 - Build date June 27, 2011 ==

Terrain database configuration South Africa The Cape datum is used for NES data sources and WGS84 is used for ORT data sources.

== Pathloss 4.0 - Build date February 20, 2011 ==

Interference calculations - certain combinations of receiver selectivity and tx emission bandwidths could cause a program crash.

== Pathloss 4.0 - Build date January 4, 2011 ==

Summary of changes made in the interference calculations using TX emission (measured or masks) and RX selectivity curves (measured or masks)

The first change came in the August 26, 2010 build to handle a very narrow band interfering signals into a very wide band receiver. The numerical integration did not adequately detect the interference in the receive passband.

The second change occurred in the November 19, 2010 build to deal with RX selectivity data which covered a frequency range of +- 2000 MHz with 10 data points. In this case, an interpolation algorithm failed. A side effect of the changes in this build was a failure to correctly read ToI
or IRF curves. This was corrected in the December 10, 2010 build.

As a result of these changes, special software was developed to test different radio data files against each other. The tests shown a discrepancy between the results using TX emission masks and measured data. This has been corrected in the present build.

== Pathloss 4.0 - Build date December 10, 2010 ==

Interference calculations using non symetrical TX emission or RX selectivity curves caused a program crash.

== Pathloss 4.0 - Build date December 09, 2010 ==

Interference calculations using non symmetrical TX emission or RX selectivity curves caused a program crash.

== Pathloss 4.0 - Build date November 19, 2010 ==

Interference calculations using user defined RX selectivity curves with wide bandwidths (~4000 MHz) and a small number of data points (~10) failed.

== Pathloss 4.0 - Build date September 20, 2010 ==

=== Microwave radio and antenna data files ===
Provision has been made to convert the ASCII version of these files to the binary format starting at a top level director and traversing the complete subdirectory structure

== Pathloss 4.0 - Build date August 26, 2010 ==

=== Interference calculations ===
Calculations involving a very narrow band interferer into a very wide band receiver and using the TX emission curve or mask and the RX selectivity curve or mask did not produce the correct filter
improvement. The new procedure first calculates the 10 dB bandwidth of the interfering signal and ensures that the numerical integration includes at least 10 data points in this bandwidth.

== Pathloss 4.0 - Build date March 17, 2010 ==

The Network move-copy function has been modified as follows:

an option has been added to limit the operation to the visible network the site coordinates in the network file are checked against the pl4 files if any errors occur a report is generated outlining the errors.

If errors are encountered, the user has the option to continue with the operation. Any files in the error list will not be transferred

== Pathloss 4.0 - Build date March 3, 2010 ==

CSV link reports revised to eliminate a file write error condition.

== Pathloss 4.0 - Build date August 12, 2009 ==

ASTER 1 arc second terrain data is now available world wide between +/-80 degrees in geotiff format. See http://www.pathloss.com/pwiki/index.php?title=ASTER for details. The Pathloss program now reads this new format. In the configure terrain database section, select SRTM-ASTER.

The Link text file import import now supports diversity antennas.

The USGS seamless server has changed the BIL and SRTM and GRIDFLOAT file formats. BIL and SRTM files are now supplied in floating point format which results in a file twice the size of the previous version without any change in overall accuracy. GRIDFLOAT data is now supplied in the
Intel data format (least significant bit first). The previous format was in the Motorola format (most significant bit first). The August 12, 2009 version reads all formats. A terrain data base configuration can have any combination of old and new files.

Note that the above does not apply to SRTM hgt files

== Pathloss 4.0 - Build date April 21, 2009 ==
Bug fixes and performance enhancements
== Pathloss 4.0 - Build date August 06, 2008 ==
The progress bar used in interference calculations limited performance on large networks.
== Pathloss 4.0 - Build date June 13, 2008 ==
The following changes have been implemented in this build:

Networks which cross the International Date line are now correctly displayed.

US terrain data in the ESRI GridFloat format is now being supplied in 1/3 second resolution. The size of these files have increased to approximately 1.4 Gb. In most cases, these files cannot be read into memory and the database operation will fail. The current build reads the elevations one by one. Note that if the file resides on a shared network drive, the create background operation can be very slow if the several of these files are required for the background. Further work is underway to improve the file reading performance

The import link text file feature now includes a cross reference between the radio and antenna identifiers in the import data and the Pathloss radio and Antenna code files. Documentation for this feature is in the file [[http://www.pathloss.com/downloads/docs/linkxref.pdf|linkxref.pdf]].

== Pathloss 4.0 - Build date November 8, 2007 ==
SRTM files at 180 degrees east or west longitude can be loaded. The Odyssey UTM database can be used for both primary and secondary terrain databases


== Pathloss 4.0 - Build date September 19, 2007 ==
Fixed metric conversion bug in the SDB import function

== Pathloss 4.0 - Build date June 26, 2007 ==

Area coverage display export to DXF files now supports the latest AutoCad verions
== Pathloss 4.0 - Build date January 12, 2007 ==

The ESRI GRIDFLOAT terrain database format has been added in this build. This has been tested with the USGS supplied GRIDFLOAT hard-drive.

== Pathloss 4.0 - Build date October 12, 2006 ==

=== Link text file import ===
A C Factor (Vigants - Barnett reliability) has been added as an input paramter.
=== MapGrid GeoTiff Files ===
Problems with some byte order formats are corrected.
== Pathloss 4.0 - Build date August 11, 2006 ==
A German translation has been added in this build. The translation was done by:

  tkt teleconsult
  Kommunikationstechnik GmbH
  Kuchengrund 8
  D-71522 Backnang / Germany
  www.tkt-teleconsult.de

tkt teleconsult also provide training for the Pathloss program

== Pathloss 4.0 - Build date June 27, 2006 ==
Batch printing worksheets (microwave and VHF-UHF) to a single pdf file can now be carried out.
Import link text file (Network module site data - site list - import) A rain file or the 0.01% rain rate can be specified as the default rain setting.
== Pathloss 4.0 - Build date March 20, 2006 ==
Corrects a crash problem associated with the radio configuration field in the Summary module.
Importing MapInfo mid-mif links corrected
== Pathloss 4.0 - Build date February 28, 2006 ==
Batch printing profiles to a single pdf file can now be carried out.

The vertical angle and minimum antenna height were added to the Microwave CSV report
== Pathloss 4.0 - Build date December 12, 2005 ==
Capri modifications for radio configuration and capacity Added the following fields to microwave CSV reports: ATPC, power reduction and 0.01% rain rate
== Pathloss 4.0 - Build date November 16, 2005 ==
Site and link text import functions in the network module were modified to handle double quotation marks text qualifiers.The site text import buffer size was increased from 256 to 2048 characters.
== Pathloss 4.0 - Build date October 24, 2005 ==
The multiselect SRTM file buffer size was increased from 256 to 4096 bytes.
== Pathloss 4.0 - Build date September 20, 2005 ==
=== Network Backgrounds ===
Revisions were made to the network elevation background displays to limit the red color to the elevations within a file which were invalid

=== CDED file conversion ===
Modifications were made to the USGS DEM to binary conversion to handle the case of the last block in the file being less than 1024 bytes.
== Pathloss 4.0 - Build date September 11, 2005 ==
Map Grid modifications to the profile clearance display added. 

Initial antenna heights are the structure heights if any

Right button click shows the clearance.
== Pathloss 4.0 - Build date August 23, 2005 ==
The color ranges in elevation backgrounds in the Network module could be affected by no data areas when using SRTM data. This was most noticeable when the elevation range was above 250 meters.
== Pathloss 4.0 - Build date August 17, 2005 ==
Switching area coverage displays in the network module from a line of sight display to a signal coverage display could cause a program crash on large networks.
== Pathloss 4.0 - Build date July 19, 2005 ==
Changing site elevations in the network module did not automatically recalculate the path inclination and elevation angles for the associated path profile.
== Pathloss 4.0 - Build date June 24, 2005 ==
There appears to be several no data values for the different sources of SRTM data. This build attempts to handle all of them. The problem shows up in the background of the network module. A single data spike can spoil the color references used to create the background.
== Pathloss 4.0 - Build date June 14, 2005 ==
The following problems have been corrected:

Bitmap icons in the Worksheets randomly did not appear on some operating systems. 

Map Grid GeoTiff files - US State Plane Coordinates - NAD83 - US Survey Feet 

GeoTiff files with the NAD83 datum and units in US survey feet did not register correctly in the index. 

SRTM bil files with units in decimal seconds (DS) did not register correctly in the index.
=== Reflection Module ===
On reflective paths, it is common practice to tilt the antennas upwards with the intention of increasing the antenna discrimination to the reflection point. This also reduces the main receive signal. The effects of tilting the antenna can now be seen in the reflection analysis module.
=== Importing Link Text Files ===
If the text files contain radio and antenna codes, these will be expanded to complete the worksheet data entry. It is now possible to import links and immediately run and interference calculation without further data manipulation.
=== Microwave Interference ===
The Interference cross reference report now includes the composite threshold degradation for multipath and rain. The update pl4 files with the interference threshold degradation selection now handles any pl4 file in memory.
=== SRTM bil and hgt Files ===
A multiselect feature has been added to create the index for SRTM bil and hgt files.
=== Canadian CDED Files ===
These are now appearing in an illegal USGS DEM file format which contains line feed characters at the end of each block. These exceptions can now be handled
=== Grid ASCII UTM terrain database ===
The use "standard UTM zones in index" option did not span files with different UTM zone numbers
=== Fresnel Zones ===
On profiles with about 5000 points, drawing Fresnel zones with the label option checked could cause a program crash.

== Pathloss 4.0 - Build date May 14, 2004 ==
Minor revisions to the raf to mrs radio file conversion
== Pathloss 4.0 - Build date March 18, 2004 ==
=== NED US & Alaska - SRTM Terrain Database ===
Data is normally entered by importing a bil file. The function Edit-Add in the grid data display did not operate correctly. It was not possible to carry out manual data entry

The JPL SRTM data is available in 1 degree x 1 degree blocks. This is a BIL format; however the files use the SPARC-MOROROLA byte order. Provision has been made to create an index of these files. The file suffix must be hgt.
== Pathloss 4.0 - Build date March 06, 2004 ==
Coverage file export to MapInfo. If one of the ranges were disabled in the coverage line attributes, the range information imported into MapInfo would be shifted.
== Pathloss 4.0 - Build date February 18, 2004 ==
Enhanced GTOPO30 terrain database files are now available from the USGS. The enhancements are based on SRTM data. Only the dem and hdr files are required. The new header file uses a carriage return for a line termination. This produces a read error in the Pathloss program.
== Pathloss 4.0 - Build date January 23, 2004 ==
The following terrain database options have been added:
* Canadian CDED 1:50,000 0.75 sec resolution
* NED CONNUS (NAD 83) indexed
* NED Alaska (NAD 27) indexed
* SRTM (WGS84) indexed

== Pathloss 4.0 - Build date October 03, 2003 ==
On space diversity systems, calculated with the "ITU-R P.530 strict - equipment signature" Regional Standards option, the value of the maximum diversity improvement factor could affect the results under the following conditions:

The overall performance was controlled by the selective component and the diversity improvement factor for the non selective component was
greater than 200.
== Pathloss 4.0 - Build date October 01, 2003 ==
NED data BIL files. This was initially released under the assumption that all elevations were 16 bit. Some files (in Florida) have 8 bit elevations. These are now treated as unsigned values in the range from 0 to +255 meters. The other possibility is from -127 to +128 meters. This latter possibility is still under investigation.
== Pathloss 4.0 - Build date September 17, 2003 ==
Additional error handling has been added to the area coverage calculation to handle data irregularities using SRTM data.
== Pathloss 4.0 - Build date July 08, 2003 ==
Area coverage calculations used an optimization technique to improve calculation times. If the hub site horizon did not change when the
mobile distance was incremented, the previous height gain calculation was used. This was not reset when the diffraction algorithm was changed in the diffraction module.
== Pathloss 4.0 - Build date July 02, 2003 Interim ==
Support for the USGS NED terrrain data provided.

Only VHF-UHF antenna data files with patterns from -180 to +180 worked. Patterns from 0 to 360 degrees did not work.
== Pathloss 4.0 - Build date June 23, 2003 Interim ==
On very short paths with large fade margins, a program crash could occur using G826.
=== Minimum K ===
The minimum value of K for a given path length is now available in the antenna heights and diffraction modules.
=== ITU530-9 ===
The area terrain roughness calculation for within 55 kilometers of the equator did not work.
== Pathloss 4.0 - Build date June 06, 2003 Interim ==
=== Microwave Worksheet ===
Space diversity operation (baseband switching / IF combining) is automatically selected when a radio data file is loaded.

When cochannel operation is selected in the Reliability dialog box, the cochannel calculation is automatically carried out. This step loads the
antenna data file and reads the antenna XPD.

The fade occurrence factor is included in the full report.
=== Network Module - Performance ===
The objectives are not scaled to the individual path lengths for G821 and G826 calculations.
=== Interference Calculations ===
Atmospheric absorption is now included on the interferer to victim RX path.
== Pathloss 4.0 - Build date April 16, 2003 ==
The following problems were corrected in the April 16, 2003 build:

Incompatible file format error messages in the Map Grid module occurred as a result of changes in the March 11 build.

Area coverage calculations using the South Africa NES terrain database could not be carried out.

A version of DTED files produced by Geomatics Canada could not be read.

Area coverage calculations carried out directly in the Network or Map Grid modules (double click on the site mark and then click the area
coverage button) could cause the program to crash if the "line of sight only" option was checked.

Sector number and site class (ptp - ptmp - remote) were added to the pl4 file - network file discrepancy. In an advanced release of this build,
the sector numbers were not initialized in the discrepancy dialog.
== Pathloss 4.0 - Build date April 1, 2003 ==

Daylight saving time problem
== Pathloss 4.0 - Build date March 11, 2003 ==
=== Network module ===
The initial data structure used in the network module had a limitation of 256 links from any site. With some point to multipoint systems, this
has been exceeded. The new limit is 64000; however, program builds prior to March 11, 2003 will not be able to read network files created with
the March 11, 2003 and later builds. The March 11 build will be able to read all network files.

The import text links feature no longer prompts to save a file. The analyze fade fade margin feature in network  sections now uses the
value of K specified in the diffraction module. You can prepare one report at K = 1.333 and another report at K = 0.666

=== VHF-UHF Worksheet ===
An option has been added to not print the log normal and Raleigh fade probabilities.
== Pathloss 4.0 - Build date March 04 12, 2003 ==
=== Network module - import text links ===
An option has been added for frequencies expressed in MHz, KHz or Hz
== Pathloss 4.0 - Build date February 12, 2003 ==
Network module link text file import - corrected problem with the 3rd tx frequency import.

File save error messages for pl4 and gr4 files have additional information to diagnose network permission issues
== Pathloss 4.0 - Build date February 04, 2003 ==
=== DTED Level 2 ===
DTED Level 2 is now supported in the following format:

DTED indexed files - The index can be read directly from the DTED file.
In the Index grid data entry form, selct Files - File Index and multiselect the DTED files.

DTED DMA directory structure.

=== Network Sections ===
Microwave frequency assignments entered in sections did not print in worksheet reports.

=== Importing frequency plans ===
The channel id is limited to 7 characters. It was possible to over-run this length with the option "add high low identifier (H or L)"

=== Radio data files raf - mrs binary conversion ===
Tabs between the data entry and the comment were not correctly converted
== Pathloss 4.0 - Build date December 13, 2002 ==
Area coverage can be calculated directly in the network or map grid modules. Doulbe click on a site legend and click the area coverage
button.
== Pathloss 4.0 - Build date December 08, 2002 ==

=== Microwave worksheet ===
The orientation loss calculation in the elevation plane will now attempt to read the elevation plane data in the antenna data file. If there is no data, the horizontal data will be used. Most microwave antennas do not contain elevation data and the requirement for this data is only over five degrees about the horizontal.

A new example "orient" is available which illustrates the differences between antenna orientation in microwave and VHF-UHF applications.

If T to I values are not specified in an ASCII raf file, the default procedure will first check for a TtoI curve and use the value at 0 frequency offset.
== Pathloss 4.0 - Build date December 03, 2002 ==

The HGRS87 datum for Greece has been added to the list of available datums.

Hellenic grid reference system (HGRS87) has been added to the list of available grid coordinate systems (projections). This is a hybrid arrangement. The geographic coordinates (latitude and longitude) are relative to the WGS84 datum. The rectangular coordinates (easting and
northing) are referenced to the HGRS system. The following parameters have been used.


Ellipsoid GRS80

  A   = 6378137.0  km
  1/F = 298.2572221
  dX = -200.1 meters
  dY =   73.9 meters
  dZ =  246.0 meters
== Pathloss 4.0 - Build date November 14, 2002 ==
Canadian CDED 3 second terrain data above 68 degrees north is now supported.
== Pathloss 4.0 - Build date November 05, 2002 ==
Additional error checking has been added to the reflection module to handle VHF frequencies.The revisions made to the multipath module in the October 28 build, contained some diagnostic printing codes. This would cause an immediate crash in any constant gradient analysis. 
== Pathloss 4.0 - Build date October 28, 2002 ==
Additional error checking has been added to the multipath module
== Pathloss 4.0 - Build date October 15, 2002 ==
Problem with map grid module using add site and move site in southern
hemisphere corrected.
== Pathloss 4.0 - Build date October 11, 2002 ==
Longitudes hemisphere correction when importing text files has been made
== Pathloss 4.0 - Build date October 08, 2002 ==
Program uninitialization and program upgrade on computers equipped with USB floppy drives has been corrected.

The G821 worst month and annual ratios for performance summaries under sections in the network module have been corrected.

Total annual performance reports did not not show the last two lines of the report.
== Pathloss 4.0 - Build date September 21, 2002 ==
Additional error checking has been added to the height gain function in the multipath module.
== Pathloss 4.0 - Build date August 20, 2002 ==
Back to back antenna passive repeaters with different polarizations on each leg did not use the correct polarizations in an interference calculation.
== Pathloss 4.0 - Build date July 19, 2002 ==
Changes to share network file operation. See the document filelock.pdf for the latest features and operations.
== Pathloss 4.0 - Build date June 26, 2002 ==
Terrain database ESRI GRIDASCII geodetic. It was not possible to edit the cell size in the index associated with this terrain database.

The gr4 file sharing on networks has been expanded to show the user the specific changes made to the file. The user has the option to reload only the changes and retain the current screen fomatting or to reload the complete file.
== Pathloss 4.0 - Build date June 3, 2002 ==
Pathloss data file (pl4) locking and Network file sharing (gr4) has been added to improve working with shared files on a network. See the
documentation filelock.pdf on www.pathloss.com.  A private directory can be specified to carry out interference calculations
== Pathloss 4.0 - Build date May 25, 2002 ==
The addition of the Odyssey MGI terrain database option, inhibited operation of the Odyssey - Gauss Kruter terrain database.
== Pathloss 4.0 - Build date May 17, 2002 ==
=== Map Grid ===
Changes to bitmap backdrop file handling to improve performance
== Pathloss 4.0 - Build date May 15, 2002 ==
=== Planet - Odyssey UTM terrain databases ===
Revisions to resolve ambiguities on systems which span the equator See document Planet_UTM on the Pathloss web site www.pathloss.com
== Pathloss 4.0 - Build date May 08, 2002 ==
=== Map grid module ===
Revisions to backdrops for bitmap files
=== Batch Printing ===
Batch worksheet printing implemented in the microwave and VHF-UHF worksheets
=== Diffraction Loss ===
Tropospheric scatter loss calculation is now an option in area coverage and diffraction loss calculations
=== Network Sections ===
Operations can be made on the associated files as well as creating new files. This provides considerable more flexibility and allows one to change the radio type on a group of files.
== Pathloss 4.0 - Build date April 22, 2002 ==
=== Network module - Import Text Links ===
When a link is imported from a text file, a transmission calculation was not made before the pl4 file was saved. In this condition, it was not possible to immediately carry out an interference calculation. The error message "no receive signal at site a" was issued.

If a terrain database is configured, a terrain profile will be automatically generated when a link is imported.
== Pathloss 4.0 - Build date April 17, 2002 ==
The MGI - WGS84 projection has been added to the map grid module Double clicking on a network file (gr4) will now start the program in
the network module 
== Pathloss 4.0 - Build date April 11, 2002 ==
=== Network module - import link text files ===
Coordinates with degrees minutes and seconds in separate columns

If the degree field for either latitudes or longitudes was negative to indicate the hemisphere, the addition of degrees minutes and seconds was
wrong.
== Pathloss 4.0 - Build date April 08, 2002 ==
Terrain database capability for the  WGS84-MGI Austria has been added as an additional option for the Planet - Odyssey databases.

=== Coordinates ===
A dash between degees and mintues and minutes and seconds was interpreted as a minus sign.
== Pathloss 4.0 - Build date March 27, 2002 ==
=== WGS 84 to MGI Austria ===
A new grid coordinate system has been added to the program. The latitudes and longitudes are referenced to the WGS 84 datum. The corresponding grid coordinates are referenced to the Austrian MGI Lambert Conforma Conic grid. The specific parameters used in the translation are:

  3 parameter WGS84 datum translation to MGI Hermannskogel
  dx = 594
  dy =  84
  dz = 471
  
  Bessel ellisoid
  major_axis = 6377397.155 ;
  reciprical flattening = 299.15281280 ;
  
  std_parallel1 = 46 N
  std_parallel2 = 49 N
  lat_origin = 48 N
  lng_origin = 13 deg 20 minutes E
  false_easting  = 400000 meters
  false_northing = 400000 meters

=== Network module CSV link reports ===
The file name and notepad fields in these reports could be placed in the wrong column.

=== Diffraction Module ===
If a range of trees was entered right up against an antenna and the height of the trees was greater than the antenna, the structure loss would be different if the profile was reversed.

=== Gauss Kruger Coordinates (Transverse Mercator) ===
The maximum easting was 5000 km. This was changed to 8000 km
== Pathloss 4.0 - Build date March 18, 2002 ==
=== USGS 30 second data conversion ===
DEM files with elevations times 10 were not correctly converted if the first column contained only 0 elevations.
=== raf-mrs files ===
4psk is an allowed modulation description and is treated as QPSK. If a tab was used between a data descriptor and the number of points (TX_EMMISSION 15) instead of a space, a read error would occur.
== Pathloss 4.0 - Build date March 12, 2002 ==
=== Network CSV Link reports (microwave and VHF /UHF) ===
The note pad was not printed since the December 10 build date. When using the single line per link option, the order of sites was either alphabetical or a geographic orientation. A new option which uses the order in the pl4 file has been added. This option will allow only the remote sites in a point to point link to be printed. 
== Pathloss 4.0 - Build date March 06, 2002 ==
The import link text feature in the network module did not carry out unit conversions if the import was set to feet 
== Pathloss 4.0 - Build date February 15, 2002 ==
Network module - The merge function now works 
== Pathloss 4.0 - Build date February 14, 2002 ==
=== Network module - Sections ===
The help file for this section is now complete. Layer setting capability has been added. 

The Text Link Import feature did not correctly handle coordinates with degrees, minutes and seconds in separate columns.
== Pathloss 4.0 - Build date Feb 01, 2002 ==
=== Microwave worksheet - Template ===
Options are provided for handling the TX channel table as follows:

  * use the tx channels in the template file 
  * keep the tx channels in the existing file 
  * erase the tx channels in the existing file
  * Network Module - CSV link reports 

The following fields have been added to these reports

  * elevation
  * tower height
  * file name
  * Area Coverage

If a set of coverage files (ter4, cvg4, prd4) was moved to another directory, the results could not be re-run. This was due to the fact that the full path names were stored in the data files.

=== Network Text Import Sites and Links ===
The coordinate format degrees minutes seconds did not handle decimals in the text file. 
== Pathloss 4.0 - Build date January 10, 2002 ==
Site elevations in prd4 coverage files were incorrectly displayed in the miles-feet units system. This is a display issue only. 
== Pathloss 4.0 - Build date January 08, 2002 ==
Terrain data reports using the copy as formatted text has been corrected.
== Pathloss 4.0 - Build date January 04, 2002 ==
=== Network module - sections ===
Generating profiles without specifying a template could cause a program crash. A misleading error message "call signs not specified at all sites" was issued
== Pathloss 4.0 - Build date December 18, 2001 ==
=== Network Module ===
The default scaling method in the network module has been changed from Arbitrary scale -fit to page to constant size.

The sub network section now analyzes the fade margins on VHF-UHF applications. Each PL4 file defined in the subnetwork is loaded and the diffraction loss is calculated and added to the worksheet. The resulting fade margin is compared to the objective and the results are written to a notepad report.
=== CSV reports - link list microwave ===
This report now handles all antenna definitions including diversity antennas. Each antenna type is listed on a separate line.
=== Import Text file ===
The import coordinate formats can be expressed as a floating point number e.g. 49.232334 or as degree minutes and seconds separated by any character including a space. The hemisphere qualifier NSEW over-rides all other settings.

In the import site text the positive longitude east / west worked backwards.

In the import link text, the file save dialog is presented under the following conditions: 

  * the first file to be saved - subsequent saves will be made in this directory 
  * the file name contains an illegal character 
  * a file with the same name exists

The mark site is now persistent. This can be erased by moving the site name of double clicking on the site legend.
== Pathloss 4.0 - Build date December 12, 2001 ==
Several problems in the Map Grid module were corrected. 
== Pathloss 4.0 - Build date December 10, 2001 ==
=== Microwave Worksheet ===
The fade occurence factor (intermediate calculation parameter) is shown in the reliability data entry form.

It is possible to import and export frequency plans as text files in the channel lookup tables.
=== Network module - CSV link reports ===
The CSV link report feature has been expanded to include VHF-UHF applications.

The reported SESR values in the CSV link report were not correct if the % Unavailability option was checked. This option is for total annual performance only and now does not affect the G821 / G826 results.
== Pathloss 4.0 - Build date November 26, 2001 ==
=== Microwave worksheet ===
The frequency selective outage calculation using the equipment signature was based on a Siemens algorithm. This has been  hanged to the algorithm in Paragraph 5.1 of Recommendation ITU-R  P.530-8/9 
== Pathloss 4.0 - Build date November 20, 2001 ==
The revisions made to the terrain data report in the October 29 program build could cause a crash on some printer drivers. 

The quad diversity improvement factor using ITU-530 methods was too optimistic. This factor is calculated as the ratio of the unprotected to the protected reliability. The actual reliability / outage calculations were correct. face=Arial,Helvetica> 

If the "treat multipath as SES only" option was checked and a radio file was loaded the option would be reset to SES and unavailability. 

Additional checking for data changes have been implemented in the Network and Map Grid modules. The user is informed that the data has changed and is provided with an opportunity to save the file. 

In the radio data entry form in the microwave worksheet, a menu item is provided to select different receive thresholds. The selection for BERses used in G826 calculations would actually calculate this value and the associated BER using the 10-3 and 10-6 thresholds using the alpha parameters. A separate menu item has been provided to carry out this calculation. 

Provision has been made to remove all interference calculations from the pl4 files. This feature is accessed in the network module from the Interference menu 
== Pathloss 4.0 - Build date November 16, 2001 ==
The tiff file reader used in the map grid module was modified to accomodate tiff files written by ATDI's map server. 
== Pathloss 4.0 - Build date November 13, 2001 ==
The angle diversity space diversity improvement factor using the Alcatel or Harris methods was too low by a factor of 10. The Nortel and ITU-530 methods are unchanged. 
== Pathloss 4.0 - Build date October 29, 2001 ==
The terrain data report has been revised to show the terrain listing without the second column. Structure descriptions now appear on the same line. 

The excess clearance view in the microwave antenna heights module now shows the latitude, longitude and grid coordinates of the point. The data can now be copied. 

Revisions made to the save as Alcatel ans file format 
== Pathloss 4.0 - Build date October 11, 2001 ==
The implementation of ITU-530-9 uses a file of global dndh values spaced at 1.5 degrees. The data retrieval procedure reads the nearest four corners and interpolates the value at the specific latitude. The interpolation procedure did not correctly determine the value. 

PL4 files containing passive repeaters can now be imported into the network module via the Site Data - Site List - Pathloss Files procedure. Note any changes made to a passive repeater either in the network module or in the pl4 files will not update the other display. A warning message is issued to this effect. 

In the network module under Site Data - Site List - Import, the Site Text and Link Files did not correctly handle a minus sign as the first character. The operation now uses the following precedents: 

If the suffix N, S for latitudes and E, W for longitudes is used, the coordinates will be formatted for these hemispheres regardless of the presence of a minus sign or the setting for positive latitudes north / south  and positive longitudes east - west. Otherwise the coordinates will be determined by both the presence of the minus sign and the hemisphere settings for latitudes and longitudes. 

eg longitude 

-0 15 32 == 00 15 32 E for longitudes positive in western hemisphere

-0 15 32 == 00 15 32 W for longitudes positive in eastern hemisphere 

 0 15 32 == 00 15 32 W for longitudes positive in western hemisphere 

 0 15 32 == 00 15 32 E for longitudes positive in eastern hemisphere 

== Pathloss 4.0 - Build date October 02, 2001 ==
Development of new features in the sub network module. These features require either the interference or coverage modules. 
== Pathloss 4.0 - Build date September 23, 2001 ==
=== Interference calculations ===
The choice of TtoI or IFR curve is established by comparing the traffic code with the TtoI curve identity. For example the following entries in the raf file: 

MODULATION 128QAM 

CAPACITY   STM1 

would generate the traffic code STM1-128QAM The corresponding TtoI curve would be identified as TtoI_STM1-128QAM  45 
in the raf file. A case sensitive comparison was made. This has been changed to a case sensitive comparison. 
=== Saved Calculations ===
The pathloss program saves all calculations including Fresnel zones, reflective planes, diffraction loss and reflection analysis. File 
corruption problems have been reported from time to time due to these calculations. This problem has been corrected. 
== Pathloss 4.0 - Build date September 19, 2001 ==
=== Network and Map Grid modules. ===
Opening and closing the site always caused the display to reset to show all sites. A manual reset menu item has been added. If there are less than 10 sites, the display will automatically reset; otherwise the existing zoom state will be maintained. Note that if a new site is added which is outside the present network area, then the site will not be displayed until the display is manually reset. 

The reset attributes under site legend, site names and link style now only reset the visible layer. If a sub network is active, the action will be limited to the sub network. 
== Pathloss 4.0 - Build date September 12, 2001 ==
Sub network capability has been added to the network module. This feature is initially used for the interference calculation; however, 
additional functionality is planned. 
== Pathloss 4.0 - Build date September 07, 2001 ==
Details of the changes in this program build are available in the document Sept-2001.pdf. This information has also been incorporated into the document [[http://www.pathloss.com/downloads/docs/addendum.pdf]]. 
=== Section Objectives ===
Define any number of sections and the performance objectives for each section. The report shows the calculated values and the objectives. This new feature is accessed in the network module under Sections - Objectives 
=== G.821 - G.826 worksheet format ===
The worksheet formats for G.821 and G.826 have been revised to show unavailability and performance for both multipath and rain in both directions. 
=== Save as Alcatel ans format ===
Pathloss files can now be saved in the Alcatel USA ans format. This is accessed under Files - Save as - Alcatel ans 
=== Radio Data Files ===
The conversion from the ASCII raf files to the binary mrs file did not add the mrs file name extension. This occurred in the May_2001 program build. 
=== ITU Rain calculation ===
The extensions to the ITU rain calculation incorporated in the July 31, 2001 program build caused a program error at frequencies below 2000 MHz.

== Pathloss 4.0 - Build date July 31, 2001 ==
=== Microwave worksheet - ITU-530 rain attenuation ===
The ITU-530 rain algorithm reduces to a quadratic equation. The solution is of the form P = (-b +- sqrt(b*b - 4*a*c) /2a. For small values of P (i.e. large fade margins), the sqrt term is negative and the calculation cannot proceed. The error message "Rain error - lower limit exceeded - ITU530" is given when the red X is clicked. To overcome the problem in this region, a value for P is now extrapolated from the curve of fade margin versus P. 
=== Microwave worksheet - Space and frequency diversity improvement factors ===
If the calculated space or frequency diversity improvement factor was less than 1, the calculation terminated. The value is now set to one. In space diversity applications, it is the responsibility of the user to remove the space diversity configuration. 

The main reason for this change is for the G826 calculation which actually carries out two separate calculations - one at the residual bit error rate and the second at the SDH SES bit error rate. If a problem occurs in the residual bit error rate calculation due to a diversity improvement factor < 1, the error situation becomes too complex. 

=== Terrain database GRIDASCII GEO and UTM ===
Minor changes were carried out to correct reading problems at the edges of map files. 
== Pathloss 4.0 - Build date July 12, 2001 ==
This build includes the ITU-R P.530-9 reliability method. The area roughness is calculated from the currently configured terrain data base. The refractivity gradient is read from the file dndz_01.bin supplied with the maintenance update. 
=== Microwave radio look up tables ===
A file in use error was registered when saving a radio lookup table after it had been loaded. 

The CSV Link reports missed some items when writing the data to the actual CSV file. 
== Pathloss 4.0 - Build date July 06, 2001 ==
In space diversity applications, the notes at the bottom of the microwave worksheet report, showed either BB switching or IF combining and did not change if this parameter option was changed. This error is a result of changes in the May 2001 program build and does not affect any calculations. 

The changes made in the June 25, 2001 program build could cause metric - implerial conversion problems when a pathloss file (pl4) in miles feet was loaded into the program set to metric defaults. 
== Pathloss 4.0 - Build date June 29, 2001 ==
A feature to import links from text files has been added. The link details must be on a single line. This feature can be accessed from the Site List in either the Network or Map Grid modules.
=== Select Import - Link Text File. ===
The horizontal scroll limit in the interference cross reference report has been increased. 
== Pathloss 4.0 - Build date June 25, 2001 ==
Grid coordinates in CSV reports would not be updated if the Update Files selection was used in the Site Data list before the report was generated. 
== Pathloss 4.0 - Build date June 10, 2001 ==
In the edit correlation procedure, the arrow showing the interference could be very large on some network displays. The goto case button in the edit correlation dialog could produce an uninitialized input data screen. 
== Pathloss 4.0 - Build date June 06, 2001 ==
Map Grid A prompt to save the background definition file is now issued Create bitmap array failed if the image file was not a tiff file Net Work Edit multipath and rain correlation could cause a program crash if there were no interference cases. Accessing the Summary module from the Network or Map Grid module could cause a program crash. Radio codes names (mrs files) have a limit of 15 characters not including the extensions. The raf to mrs conversion now warns the user that the file will be truncated if the name exceeds this limit. Microwave Worksheet Misleading error messages could occur when the G826 calculation option was selected. BBER and ESR for multipath and rain are now added together. 
== Pathloss 4.0 - Build date May 30, 2001 ==
This release includes the May 2001 program enhancements. See the web site for the May 2001 documentation. Coordinate transformation capability for all sites in the network display has beem added. This is accessed from the Network module under Site Data - Site List - Transform Coords. The coverage line attributes can now be accessed from the network and map grid modules under the defaults menu selection. A hatched option has been added which offers some measure of transparency. The lowest coverage level (below level) was previously drawn as an outline of the coverage area. It is now drawn exactly the same as the other ranges. It is now possible to show only those areas which are below the lowest range. 
== Pathloss 4.0 - Build date May 22, 2001 ==
Beta release of the May 2001 program build. Frequency added to Harris export 
== Pathloss 4.0 - Build date March 21, 2001 ==
Harris file export revisions 
== Pathloss 4.0 - Build date March 16, 2001 ==
Area coverage module Provision has been made to extract the radial terrain data information from version 3.0 or version 4.0 pathloss data files as an alternate to using a terrain database. 
== Pathloss 4.0 - Build date March 08, 2001 ==
The program could not be initialized on computers with a floppy drive connected to a USB port. 
== Pathloss 4.0 - Build date March 01, 2001 ==
Coordinate transformations between the NAD27 and NAD83 datums for the United States (including Alaska, Hawaii, Puerto Rico and the Virgin Islands) now use the NADCON data sets. This change affects coordinate transformation and operations using the USGS 30 meter (7.5 minute quads) terrain database. 

The Swedish Coordinate system has been added to the Gauss Kruger coordinate system. The data format for the latitude and longitude origins has been expanded to allow entry in degrees minutes and seconds. 
  
=== Interference ===
A network display with two links between the same two sites implemented as two separate Pathloss data files would not calculate. The program logic required more than two sites to allow the calculation. Furthermore, if both links had the same frequency the program would assume that this was the coordinate transmitter and the case would be ignored. The present logic to ignore a case is as follows: the victim and intererer frequencies are equal and the interferer is located at the victim,s coordinate site and the victim is located at the interferer's coordinate site and the victim and the interferer are from the same Pathloss data file 
== Pathloss 4.0 - Build date February 16, 2001 ==
The clearance display in the antenna heights module used in VHF-UHF applications would use the second set of clearance criteria which could only be accessed when a microwave application was active. 
The Gauss Kruger coordinate system has been implemented asa generalized Transverse Mercator projection. See the document gauskrug.pdf on the CTE web site for details (www.pathloss.com) 
  
=== CSV site and link reports (Network Module) ===
String values are now enclosed in "". It has been reported that not all fields print; however, this problem has not been simulated. Interference Case Detail Report The modify - pathloss data file function did not carry out the following: 
  
   * If a receiver did not have a threshold degradation, the file was not changed. The program will now erase the threshold degradation in the pathloss data file if the interferenece analysis does not include one. 
   * If a file contained multiple frequencies (1 for N), the receiver was modified for the last interference case. The worst threshold degradation is now used. 

== Pathloss 4.0 - Build date February 05, 2001 ==
Irish grid coordinate conversion Certain easting and northing combinations could cause a lock up when using the import text file in the site list in the network module. 
== Pathloss 4.0 - Build date Jauary 10, 2001 ==
The binary conversion of ASCII VHF-UHF antenna files did not work following the November 2000 revisions to the new NSMA format 
== Pathloss 4.0 - Build date December 27, 2000 ==
The antenna diameter was not transfered in the template function in the microwave worksheet. The inverse and forward coordinates data entry forms in the terrain data module could cause a program crash if the cancel option was selected. 
== Pathloss 4.0 - Build date December 18, 2000 ==
Area Coverage Coverage sectors whose end azimuth was 360 degrees could lock the program. 
== Pathloss 4.0 - Build date November 21, 2000 ==
The single file interference analysis could cause the file to reverse each time the interference calculation was run 
== Pathloss 4.0 - Build date November 15, 2000 ==
=== Intra System Interference Calculations ===
An update pathloss data files feature has been added to enter the threshold degradations into the individual pl4 files. This feature is accessed in the case detail report. Select Modify - Pathloss data files. The composite threshold degradation and the number of interference exposures will be added to the worksheet data. 
Microwave antenna patterns supplied by Andrews in the new NSMA format do not include the FSTLST field in the RPE data. The file conversion to the binary MAS format will ignore this value if it is missing instead of giving an incompatible file format error. 
== Pathloss 4.0 - Build date November 08, 2000 ==
ESRI GRIDASCII Terrain Data An option has been added to interpret the nodata values (-9999) as either sea level or to ignore elevation. The previous version always assumed that a nodata value was sea level. Note that it will be necessary to reconvert the ascii files to the binary format in order to use this option. The previous conversion assiged a zero to the nodata value. 
=== CSV Link Reports (Network Module) ===
The following fields have been added to this report: 
  * emission designator 
  * atmospheric absorption loss 
  * annual multipath 
  * annual rain 
  * total annual 
  * worst month multipath 
  * worst month rain 
  * worst month unavailabilty 
  * worst month ses 
  * the contents of the note pad 

The reliability can be expressed as outage seconds, percent availbility and percent unavailability in the report options. 
== Pathloss 4.0 - Build date November 01, 2000 ==
=== VHF-UHF Ascii Data File (*.vaf) ===
The initial format for these files was taken from "NSMA 16.2.4" and is described in the pathloss documentation. A newer format "NSMA WG16.99.050" is now also supported. The documentation for this format is available from www.nsma.org. All ascii VHF-UHF antenna data files have been converted to the new format. 
=== Microwave Ascii Data Files ===
Manufacturers have begun supplying microwave antenna ascii files in the "NSMA WG16.99.050" format. The documentation for this format is available from www.nsma.org. The conversion will automatically detect the format. 
=== Network Site Name Attributes ===
An function to reset the positions of the site names to the default values is provied in this release. A pushbutton is provided in the Default Site Name Attributes dialog. 
== Pathloss 4.0 - Build date October 26, 2000 ==
Coverage module Fixed problem with metric conversion problem on coverage displays which were originally generated in miles and feet 
== Pathloss 4.0 - Build date October 24, 2000 ==
Interference Calculations Intra system interference calculations for the currently loaded file can be run against the network. This option must be selected in the intra system interference dialog box. 

IMPORTANT NOTE - when using this option, the data for the memory file is taken from the file in memory. All other data is taken from the files on disk.

OHLOSS calculations in the case detail report can now be run for all OHLOSS cases. If an OHLOSS calculation shows that the path is line of sight, then that path will no longer be considered as an OHLOSS case. 
=== Move / Copy Network Files ===
This feature will move or copy the network file including all associated pathloss data files to a new folder.

The layers in the network module did not always check that both ends of a link were on a visible layer. This occured in CSV reports and in interference calculations.
=== Planet - Odyssey Terrain Data ===
An option has added to this terrain data base format when the data contains embedded buildings and trees. The elevation at the center of the cell is read instead of the weighted average of the four corners. 

The optional logo is now printed as a device independant bit map. This may correct the logo printing problems reported for some printer models. 
== Pathloss 4.0 - Build date October 17, 2000 ==
DTED USDMA directory strucure. The program interpreted 0 longitude as being in the western hemisphere. The eastern hemisphere is required to set the correct file name. Terrain data reports would not print on files which included passive repeaters. 
== Pathloss 4.0 - Build date October 11, 2000 ==
The error message "Load Notes Failure" could cause a program crash. The FCC EIRP warning did not work on Site 2 Small version 2.0 files did not load. 
== Pathloss 4.0 - Build date September 29, 2000 ==
The import text file function in the network module did not work with space or tab delimited files. A tab must be specified as \t in the delimiter character text entry. In the import text file in the terrain data module, only comma delimited files could be imported. Space and tab delimiters are now recogized. 
== Pathloss 4.0 - Build date September 04, 2000 ==
Coordinate entry in the southern hemisphere using a minus sign did not work since the August 25, 2000 program build 
== Pathloss 4.0 - Build date August 29, 2000 ==
Height above average terrain has been added. In the terrain data module, select Operations - HAAT. The calculation requires a terrain data base and is made in the range 3 to 16 kilometers. 
== Pathloss 4.0 - Build date August 25, 2000 ==
Odyssey UTM index function will accept negative values for the edges. Structures on version 2.0 files did not load properly. Clicking on a very dense network could cause a program crash if the number of links or sites under the cursor exceeded 48. The tolerance for the addition of range has been changed from 100 meters to one meter. If the distance from the select point to the nearest profile point is less than this limit, then the profile point will be used for the range start or end. 
== Pathloss 4.0 - Build date August 02, 2000 ==
Grid control scrolling using thumb tracking could produce erratic results. The Odyssey UTM terrain database index did not accept negative values for the extents of the file. These can occur when the data is reference to a non standard UTM zone. Terrain View had problems in the southern hemisphere due to changes in the July 12 build. 
== Pathloss 4.0 - Build date August 01, 2000 ==
Grid control scrolling using thumb tracking could produce erratic results. The Odyssey UTM terrain database index did not accept negative values for the extents of the file. These can occur when the data is reference to a non standard UTM zone. 
== Pathloss 4.0 - Build date July 12, 2000 ==
Moving site names in the network module now shows the site to which the site name applies. UTM coordinates can apply to either the northern or southern hemisphere. This ambiguity required the user to enter the northing as a negative number in the southern hemisphere. This has been solved by adding the letter N or S to the UTM zone i.e. 10N or 10S. If the letter is not entered, the default hemisphere (Configure - Geograpic Defaults will be used) 
== Pathloss 4.0 - Build date June 28, 2000 ==
Clutter calculations made in the diffraction module were not automatically transferred to the worksheet. Additional error checking was added to the tree loss calculation. Terrain views which covered areas north and south of the equator would not display. Provision to add sites in a text or CSV file into the site database has been added. This feature is under SDB - Add-Edit - Text-CSV files. 
== Pathloss 4.0 - Build date June 13, 2000 ==
The following changes were made to the rapid deployment feature: 
CSV report expanded to include free space loss, atmospheric absorption loss and availability 
The interference correction power increment does not operate on short links with a receive signal higher than the design receive level. 
Intra system interference Very long file names could cause a program crash when certain error messages were generated in the error log file. 
== Pathloss 4.0 - Build date June 07, 2000 ==
Additional error checking added to the diffraction and reflection modules to check for corrupted calculations and reflfective planes. The CSV site reports in the network module could cause a crash if no valid files were encounterd. The ESRI Grid Ascii UTM terrain data base, now allows all database reads to be reference to a specific UTM zone. An embedded building option is provided. In this case the average cell elevation is used. 
== Pathloss 4.0 - Build date May 20, 2000 ==
The data entry of the included angles on double passives repeaters did not operate correctly. Intra system interfence cross reference report The traffic code for both the victim and interferer has been added to this report. CSV Reports Two new comma delimited file reports have been added in the network module. These are through the menus: Site Data - Site List followed by Reports - CSV site list or CSV link list The user selects the fields to display. Both the site list and link list reports use pl4 file data only. Rapid Deployment A new transmission design report has been added. The operation is similar to the new CSV reports above. The user selects the fields to display. 
== Pathloss 4.0 - Build date April 26, 2000 ==
The import text file in the network module now allows the user to select the latitude and longitude sign conventions used in the file to be imported. The latitude and longitude entries in the ITU-530-6 and ITU-530-7 geoclimatic factor dialog box were not following the sign conventions specified in the Geographic Defaults. 
== Pathloss 4.0 - Build date April 18, 2000 ==
The New Zealand grid has been added to the Odyssey terrain database. A generalized text file import feature has been added to the indexes. This allows the user to define the fields and set particular options on the import. Indexes from Planet, Nokia Alcatel 955 and Comserarch data bases can be imported into the Odyssey index. The GridAscii UTM database could produce spurious elevations in the network background display. The data base did not work in the southern hemisphere. 
== Pathloss 4.0 - Build date April 11, 2000 ==
Rain performance in accordance with ITU-530-8 has been implemented as a seperate option. UK Ordnance Survey data base has been implemented under the Odyssey UK Grid. 
== Pathloss 4.0 - Build date April 03, 2000 ==
Odyssey terrain database UTM format did not work in the southern hemisphere 
== Pathloss 4.0 - Build date March 14, 2000 ==
The March 07 program build introduced a potential crash in the microwave worksheet. 
== Pathloss 4.0 - Build date March 07, 2000 ==
Error checking added to terrain data module to ensure that calculations will be erased if the terrain profile is modified. 
== Pathloss 4.0 - Build date February 29, 2000 ==
Diffraction Module The height gain algorithm is inhibited on line of sight paths. Network Module Traffic code and azimths have been added to the automatic label generation. The constant size option could set the label point size to zero Microwave Worksheet The date is printed at the end of the worksheet along with the calculation options. Summary Module The summary reports for VHF-UHF applications showed the antenna gain in dBi instead of dBd Odyssey-Planet UTM terrain database It is now possible to force the program to use a single file. This is required when a single file is used for several UTM zones. When a site or station was imported from a database into the program using the Summary module, the elevation and tower heights were not immediately registered in the Summary module. 
== Pathloss 4.0 - Build date February 18, 2000 ==
Duplicate distance checking in the terrain data module did not always work. The clutter calculation in the diffraction and area coverage modules could cause a program crash on some computers The windows GDI (graphic device interface) will fail if a certain number of points is exceeded. The maximum number depends on the operating system (95, 98, NT). An error message is issued and the profile will not be generated if the number of points exceeds 15000. The Constant Size scaling in the network module could cause a crash if the display was printed. 

== Pathloss 4.0 - Build date January 19, 2000 ==
Microwave worksheet The latitudes and longitude entries in the ITU 530-6 and 530-7 geoclimatic factor dialog boxes did not follow the sign convention specified in the Geographics Defaults dialog. VHF-UHF worsheet The receiver multicoupler loss entry could only be a positive number. This has been changed to allow a negative number to be entered. This denotes an amplifier gain. 
== Pathloss 4.0 - Build date January 11, 2000 ==
=== Network Module ===
Topographic backgrounds can be added to the network display. Refer to the document [[http://www.pathloss.com/downloads/docs/addendum.pdf|addendum.pdf]] for details of this feature. An add site feature has been added. In conjunction with the topographic backgrounds, this feature shows the coordinates and elevation at a point on the display. A new scaling option has been added which maintains text sizes and legend sizes constant independent of the zoom level. 
=== Rapid Deployment (Interference option only) ===
Initial release of the rapid deployment feature. Refer to the document [[http://www.pathloss.com/downloads/docs/rap_depl.pdf|rap_depl.pdf]] for details. This release includes the rain cell scanning feature. 
=== GTCo Digitizer operation ===
The digitizer did not work on Windows NT platforms Antenna lookup tables without an antenna diameter, would result in a undefined antenna diameter if loaded into the worksheet set for miles-feet. 
=== Micropath 6 set CD-ROM terrain data ===
The program could not access the Alaska CD-ROM 
=== Print Profile (VHF-UHF Applications) ===
Under some circumstances, the display settings would not be saved in the flat earth - K on ground profile format. 
=== Diffraction Module ===
Added additional error checking to handle certain saved calculations in the pathloss data files. 

== Pathloss 4.0 - Build date November 16, 1999 ==
MapInfo Export A MapInfo export is now available for area coverage analysis 
== Pathloss 4.0 - Build date November 07, 1999 ==
=== MapInfo Export ===
The MapInfo Export in the Network module has been completely revamped. Previously the export was accomplished using a combination of DXF files and a dBase5 table. Sites, links and the grid are now exported in MapInfo drawing exchange format. See [[http://www.pathloss.com/downloads/docs/addendum.pdf|addendum.pdf]] for details of the exported data. Multipath Module Additional error checking has been added to handle random program crashes in a height gain. I believe that the problem has been solved with this build. Pathloss 2.0 - 2.2 file This older file format is now supported. 
== Pathloss 4.0 - Build date October 31, 1999 ==
=== Profile Generation ===
If the Generate button was clicked again after the profile generation was started, the program could crash.
=== Network module - Site List ===
Attempting to sort the site list by the PRD file name column would cause a program crash.
=== Rapid Deployment ===
This build contains a preliminary release of the rapid deployment feature for Triton radios. Point to point radios will follow shortly complete with documentation. 
== Pathloss 4.0 - Build date October 11, 1999 ==
=== Radio Data Files ===
The ASCII to binary conversion of ASCII radio data files (*.raf) did not consider tabs as a deliminiter between the mnemonic and the data. Default transmit emission and receive selectivity masks are created using the spectrum 3 dB bandwith only. In addition to the spectrum bandwidth, previous versions required a valid modulation to be specified. If the ASCII data file does not include cochannel T to I values for similiar and CW modulations, default values will be entered if a valid modulation has been specified. 
== Pathloss 4.0 - Build date October 01, 1999 ==
Copying the worksheet as a graphic now adds the calculations and notepad contents after the worksheet. 
== Pathloss 4.0 - Build date September 17, 1999 ==
=== Summary Report ===
The transmit channel assignments have been reformatted to show the ATPC and power reduction in addition to the channel ID, TX frequency and polarization. Reports The copy as graphics menu selection is only valid in worksheet reports. This menu item has been disabled in all other text reports. 
== Pathloss 4.0 - Build date September 12, 1999 ==
=== Microwave Worksheet ===
The additions of TX channels in the September 08 build resulted in the report headers being out of sync with the worksheet data. 
== Pathloss 4.0 - Build date September 09, 1999 ==
=== Single profile generation ===
If the digital map file path was very long, a single profile generation could cause a program crash. Area coverage and terrain view did not produce this proglem. 
== Pathloss 4.0 - Build date September 08, 1999 ==
=== USA 3 Second Terrain Data ===
Programs shipping to the United States include a CD-ROM containing compressed 3 arc second data for the 50 states. The source of this data is the USGS 1:250,000 DEMs. The program reads the compressed data directly. See [[http://www.pathloss.com/downloads/docs/addendum.pdf|addendum.pdf]] or the help files for a description of this new terrain database. 

=== Operations using the Borland Database Engine (BDE) ===
Intra system interference calculations and all site database operations use BDE. Several problems with directory (folder) naming conventions have come up. It appears that international characters and spaces are not allowed. For example, the My Document folder cannot be used for a site data base. If the BDE error message "Invalid directory" occured in an intra system interference calculation, a program crash would occur. This has been fixed. Furthur investigations are continuing. 
=== Microwave Worksheet ===
The TX channel assignments and polarization are printed as line items in the worksheet report. 
=== Space Diversity Improvement Factor ===
A third option (Harris) has been added to the space diversity improvement factor calculation methods. The Harris method usess the Vigants space diversity improvement factor for both flat and dispersive fade margins. Another option for quad/hybrid diversity improvement has been added which uses the sum of the space and frequency diversity improvement factors. 
=== Default File Names ===
A default file name is created using the site names. If the site names contained illegal file name characters i.e. "\/.?*<>", the file save dialog box would not be created. The file would not be saved and there was no warning. Illegal characters are now stripped from the default file name. Spanish language revisions supplied by BellSouth Ecuador have been implemented. 
=== MapInfo Export ===
The network module now includes an export to MapInfo. The sites are exported as a dBASE5 table, The link lines and grid can be exported as DXF files. Note that the coordinate system in the DXF files uses latitude and longitude. This simplifies the traslation to the MapInfo coordinate system; however, if the file is loaded into any other program, the geographic representation will be lost. 
=== Link Layers ===
The right click link popup menu, now includes a Layer selection in which the link layer can be set. 
=== Network Printing ===
The Print menu selection in the Network module, now has the options of printing to file or multiple copies. 

== Pathloss 4.0 - Build date August 16, 1999 ==
The following terrain databases were not correctly coded as indexed databases: AUSLIG_3 second, South African National Exchange Standard, MTD (Spain) The effect was to misreport missing files.
=== Intra System Interference ===
High Low Violations This report could not be accessed if there were no interference cases. The August 10, 1999 program build did not correctly calculate filter improvement for negative frequency seperations. TX Channel Assignments When power reduction reduction was specified in a TX channel assignment, the effect was to increase the power instead of decreasing it. In addition, the power reduction could only be a positive number. This has been revised as follows: If a positive power reduction is specified, the transmit power will be reduced by the specified amount. If the power reduction factor is negative, the transmit power will be increased.
== Pathloss 4.0 - Build date August 04, 1999 ==
=== Radio Data Files ===
Curves for interference reduction factor have been added to the radio data files. These are effectively filter improvement curves. The format is: IRF_[traffic_code] [number of points] e.g. IRF_2E1-4QAM 33 0.00  -0.02 1.75  -0.11 3.50   0.14 5.25   0.83 7.00   1.22 .
=== Terrain View ===
A use palette option has been added to the terrain view dialog box. This should only be checked if the display cannot render the RGB colors.
=== Worksheets ===
Path distance is now automatically entered into the worksheet using the distance calculated from the coordinates if a terrain profile does not exist. 
== Pathloss 4.0 - Build date July 27, 1999 ==
This following additions and corrections have been made in this release: Microwave Worsheet Threshold to Interference ratios were negative when directly entered into the radio data entry form. The problem did not occur when lookup tables or radio data files were used. Terrain Databases The setup procedure did not show the correct data base name in the database setup dialog boxes. This was a side effect of inserting the Odyssey Irish and UK grid options. Changes were made to the GRIDASCII UTM conversion to handle the ESRI's new composite terrain and building databases. 
== Pathloss 4.0 - Build date July 18, 1999 ==
This following additions and corrections have been made in this release: Network Module Link label capability has been added in both a free format and an up dateable fixed format. Microwave Worksheet When the microwave worksheet was calculated, the data changed flag was set. This produced superfluous warning messages that the data had changed. Single Rectangular Passive Repeater If the difference between the true azimuths of a single passive repeater was greater than 180 degrees, the included angle was not correctly calculated.
== Pathloss 4.0 - Build date June 30, 1999 ==
This release adds the UK and Irish national grid coordinates. In conjunction with this, two new options have been added to the Odyssey terrain database to support these grid coordinate formats. The documentation is available in the maintenance file [[http://www.pathloss.com/downloads/docs/addendum.pdf|addendum.pdf]].

In some indexed terrain databases, if a file in the index could not be found, this was interpreted as a file read error and the database (primary or secondary) was locked out. 
== Pathloss 4.0 - Build date June 20, 1999 ==
The terrain view color ramp has changed and a color legend has been added. This release corrects the following problems: Loading a pathloss data file in the terrain data module, could result in a display with the structures drawn above the profile. The workaround was to change to another module and then return to the terrain data module. Long file names (40 characters not including the full path) could cause problems in the network module. The reflective plane used in the reflection module could result in an invalid plane if the cancel button was clicked after the plane had been defined. 
== Pathloss 4.0 - Build date June 09, 1999 ==
This build includes draft French and Spanish language files for screen displays and reports. These are not complete and are under review. Network Module Multiple links between two sites is now possible. These links must be added by importing pl4 files in the Site List. This will allow interference analysis of several radio links on the same path. A new report (frequency plan) has been added to the Site List. This report lists the frequencies, channel ids, polarization and for each link and the associated pl4 file. Coverage Module This build corrects the random variation in the progress bars for a large number of radials (720) and potential program crashes when the line of sight only option had been selected. 
== Pathloss 4.0 - Build date June 02, 1999 ==
This build corrects the following problems: Entering a zero frequency in the TX channels table would cause a program crash on frequency diversity applications in the microwave worksheet. The "use clearance criteria" option in the print profile module was intended to be used only with the flat earth K on ground profile format. Values of K and fresnel zone references in the curved earth formats were also set to the clearnce criteria if this option was checked. In the intra system case detail report, if a case was printed immediately after an OHLOSS calculation or a parameter modification, the program would crash. 
== Pathloss 4.0 - Build date May 31, 1999 ==
3.0 template files are now supported in version 4.0. The procedure is to load the template file using the Files - Open menu selection. This step reads and converts the version 3.0 template file to a standard Version 4.0 file. If the template will be used in an interference calculation, edit the template file as required to include the antenna and radio codes and the T to I and 10-6 BER thresholds. Save the file. The extention tpl is no longer used in version 4.0. Any pathloss data file can be used as a template. Multi Site Area Coverage Adding a new site in a network site list which contained an active coverage caclulation could cause a program crash. Oahu USGS 7.5 minute terrain database The 1.5 minute shift in the longitude for the 7.5 minute maps for the island of Oahu has been taken into account. 
== Pathloss 4.0 - Build date May 26, 1999 ==
The conversion of USGS 7.5 minute DEMs now handles 10 meter horizontal spacing. Previous builds were limited to 30 meters. Field strength calculations in the VHF-UHF worksheet and coverage module has been changed to the definition in ITU-R PN.525. The results are now identical to pathloss version 3.0. The results of previous builds will be approximately 2.2 dB different. The north - south reference arrows on coverage displays were not positioned at the radial ends on segmented displays. On coverage displays using field strength criteria, the mobile antenna gain is not included in the legend. The parameters box in the print profile module would display diversity fresnel zone references on non diversity applications. 
== Pathloss 4.0 - Build date May 12, 1999 ==
The May 11, build introduced a program fault when any of the DTED - USGS 1:250,000 DEM files were verified. Pathloss Version 4.0 - Build date May 11, 1999 Terrain database support for the the MDT - Spain format has been added in this build. The no data values (-999) are set to zero. Tree loss was not printed in diffraction loss reports. An area coverage segment which included a zero azimuth (e.g 310 degrees to 25 degrees) did not work. The coverage wase calculated the coverage from 25 deg to 310 deg). A new coverage project now resets the x and y drawing offsets to zero. When a coverage calculation was added in to the network module, the drawing extents were not correctly adjusted. A new option in the page setup dialog to retain the original drawing size. The Update files function in the Network Site List gave misleading displays if the data file did not include elevations. If the Micropath 3 second database was selected as the primary, the secondary data base selection was ignored. Revisions made to multiselect file open dialog boxes. The buffer size on the print profile batch print and the network import pl4 files has been set to 8192 bytes. All others are set to 4096 bytes. 
== Pathloss 4.0 - Build date April 21, 1999 ==
This build corrects the following: If a file was saved as version 3.0 (pl3) and the initials field in the print profile title block was longer than 2 characters, a file read error would occur when it was loaded into the version 3 program. The coverage file name is now shown in the drawing legend. The Micropath 6 CD-ROM set database would not read files for coordinates west of 160 degrees. The limit has been changed to 180 degrees to allow access to new maps for the Aleutian islands. USGS 30m file conversion now recognizes elevations which have been multiplied by a factor of 10. 
== Pathloss 4.0 - Build date April 18, 1999 ==
This build adds the following features to the network module The link list can now be sorted. The design modules can be accessed from the link list. The site list has a Mark Site menu selection. This closes the site list and draws a 1/2 inch blue circle around the selected site. This will help identify a site location in very dense networks. When an interference calculation is invoked, the program checks for the same call sign at different sites. The high low violations report keys on call signs and does not work unless each site has a unique call sign. The program did not release the memory used by coverage displays imported into the network module on program termination. The channel violation report could cause a program crash when a link was selected after the report closed. Area Coverage A 2 mm site mark is drawn on the solid coverage displays. The first level radius in the staggered radials selection (Select Print - Page Setup) is used to clear the center of the display. The radial displays can be saved as DXF files. If a solid coverage display is saved, only the polygon outlines are drawn. At this point we do not know the DXF format for a filled polygon in AUTOCAD. A subsequent build will include DXF file transfer for the legend. Terrain View Somehow the terrain view display lost its axis rotation capability along the way. Note that on Window 95/98, there are some problems. Best results are with Window NT Changing antenna heights using Configure - Antenna Heights could cause misleading profile displays in some modules. 
== Pathloss 4.0 - Build date April 06, 1999 ==
This build corrects the following problems: On Windows NT, clipboard operations did not size correctly on profile screen displays. Attempting to print or copy the antenna heights display could cause a computer crash. The high low violation report memu selection is now inhibited unless a valid interference analysis exists. 
== Pathloss 4.0 - Build date March 28, 1999 ==
Interference A high-low violation report has been added. This prints a listing of all transmit frequencies used in the analysis. High low violations are detected using the channel id naming convention (the letters H or L must be the last letter in the id) Diffraction changing antenna heights in the diffraction module using configure - antenna heights could cause the program to freeze. Additional error checking has been added to the algorighms. GTOPO30 global 30 arc second database The USGS 30 second database name has been changed to GTOPO30. The setup procedure now simply sets the directory. The database now uses a file naming convention to span multiple files. VHF-UHF Worksheet Radio lookup tables could cause a crash under some circumstances 

== Pathloss 4.0 - Build date March 21, 1999 ==
=== Windows NT Issues ===
The font size on the axis of profile displays did not represent the selected point size. 

The network and coverage display did not copy and paste correctly.

=== Intrasystem Interference ===
An interference cross reference report has been added. Each case is sumarized on a single in landscape orientation and uses the same case - subcase numbering as the case detail report. The intent is to first print this report and then use the examine the case detail.

A "Go to Case Number" button has been added which will allow you to selectively examine a case without toggling through all of the interference cases.

Sorting capability has been removed from the TX channel assignments lookup tables

== Pathloss 4.0 - Build date March 15, 1999 ==
=== Network module ===
Clicking on a site legend or link, in cases where the sites of links overlapped, resulted in the selection of the first site. If multiple sites or links are detected, a selection is now presented to the user. When a pathloss data file is imported into the site list, the file name will always be updated, even if the link already exists.
=== USGS 7.5 minute (30 meter grid) database ===
The ASCII to binary file conversion utility used a no-data value of -3200. The correct value is -32000. This could produce a glitch on the profile under some circumstances. Note that it will be necessary to reconvert all ASCII files to correct this.
=== Terrain databases - general ===
If the database files were located in the root of a drive, the files would not be read on some databases. 
=== General ===
File operations which allowed a multi selection were limited to approximately 12 files. This limit has been increased by changing the buffers size from 260 to 4096 bytes.

The pathloss program requires a default printer to access the network and coverage modules which determine the page size from the default printer. Additional error checking has been added to determine if a default printer exists.
=== Intra System Interference ===
The noise threshold calculation has been changed from NT = RX_THRESH_10_6 - T_TO_I + 6 dB to NT = RX_THRESH_10_6 - T_TO_I + 5.868253 dB. The obective was rounded e.g. -91.2 dBm would be shown as -92 dBm. This figure was only used as a test to clear interference cases. The net effect of these changes will be to reduce the calculated threshold degradation by 0.13 dB. Note that these changes will only appear in a new calculation. Existing calculations are stored in database tables and therefore will show the old values. 
== Pathloss 4.0 - Build date March 8, 1999 ==
Transmit channel assignments are now in a single data entry form complete with lookup table support. Please read the associated help file on the channel id naming convention. The letter H (high) or L (low) must be the last letter in the channel identifier in order to be correctly interpreted in an upcoming high - low violation report. On text reports the logo displayed on the screen did not switch on and off in response to the "use logo" option in the Page Setup dialog. The actual reports were printed correctly. 

Antenna clearance reports showed off path distances in kilometers/miles instead of meters/feet 

== Pathloss 4.0 - Build date February 28 1999 ==
First build of the final release of Version 4.0