ntia / p528-gui

A graphical user interface application for Recommendation ITU-R P.528

Rec ITU-R P.528 GUI

Persistent Identifier:

This code repository contains a Graphical User Interface (GUI) frontend to the U.S. Reference Implementation of Recommendation ITU-R P.528. It allows a user to set input parameters and generate a loss-versus-distance curve with modes of propagation (Line-of-Sight, Diffraction, and Troposcatter) identified.

Inputs

• Height of the low terminal
• Height of the high terminal
• Frequency
• Time percentage
• Polarization

See p528 for additional details on these input parameters.

Outputs

The image below illustrates p528-gui for an example set of input parameters. The data representing this figure can be exported to a CSV data file.

Configure and Build

The tool is built on the .NET Framework and Windows Presentation Foundation, and is thus limited to execution on Microsoft Windows. It uses the OxyPlot package for the rendering of the plot.

Install

To aquire a pre-built executable of this tool, navigate to the Releases page and download the most recent release. Once downloaded, unzip the .zip file such that all the files are in the same folder. Double-click on the .exe file to launch the application. Recommendation ITU-R P.528 comes bundled with the executable.

References

• Recommendation ITU-R P.528
• U.S. Reference Implementation of Recommendation ITU-R P.528

Contact

For questions, contact Billy Kozma, [email protected]

p528-gui's Issues

CSV export doesn't contain any data

In a particular situation, the CSV data export products a file with no data - only 0's.

To reproduce:

1. Open app and press "Render"
2. Switch units to ft/n miles
3. Press "Render" again
4. Export CSV data

The csv output file wont have any data - only 0's. See the attached output.csv as an example.
output.csv

This bug was reported on 10-Dec by Robert Witzen of International Civil Aviation Organization (ICAO).

Support unofficial upper frequency limits

Changes made to P.528 to allow higher than frequency limits than defined in Recommendation text are detailed in NTIA/p528#12

Updates to the GUI should be made to support and reflect addition of warning flags.

Full support down to 100 MHz and up to 30 GHz

The current application shows a warning if the entered frequency is between 100-125 MHz, as this frequency range is not part of the official Rec. The newly proposed P.528-5 has a lower frequency limit of 100 MHz, so this warning should be removed.

Incorrect Min Low Terminal Height Error Message

If the user operates in "Multiple Low Terminal Heights" mode and enters a Terminal 1 Height less than the min (either 1.5 for meters or 5 for feet), then they are shown an error message incorrectly referencing Terminal 2.

Update Input Validation to use Data Binding and Validation Rules

Input validation is currently implemented manually. And values are manual read/write to input textboxes. Leverage WPF databinding and validation features to reduce and simplify the code, while also making it more robust.

Add support for polarization input

The proposed P.528-5 revision supports both horizontal and vertical polarization. Update the UI controls to support this user defined input parameter

Update Y-Axis to Basic Transmission Loss

The y-axis should be updated to show basic transmission loss (positive value), instead of basic transmission gain (negative value). This is changed from P528-4 to P.528-5. The orientation of the plots should remain the same for familiarity, which means larger values should go down on the y-axis

Program crash if all modes of prop are not present in curve data

If a user generates a curve which does not include data for line-of-sight, diffraction, and troposcatter regions, the application will crash. An example of this is if the x-axis distance is reduced such that the maximum value of the x-axis is less than the minimum distance for troposcatter to be predicted for a given link geometry.

The cause of this is that the program ensures the curve is continuous by taking the first diffraction point and adding it to the last point in the line-of-sight line segment (same with troposcatter/diffraction). However, the program does not first check to make sure the point exists. Hence, if the data was generated such that there are no diffraction and/or troposcatter data points, this operation causes the program to crash.

This bug was reported on 10-Dec by Robert Witzen of International Civil Aviation Organization (ICAO).