C++ Implementation of Recommendation ITU-R P.452

This code repository contains a C++ software implementation of Recommendation ITU-R P.452 with a prediction procedure for the evaluation of interference between stations on the surface of the Earth at frequencies above about 0.1 GHz.

Version

This implementation corresponds to the original reference MATLAB/Octave implementation of Recommendation ITU-R P.452-18 approved by ITU-R Working Party 3M and published by Study Group 3 on ITU-R SG 3 Software, Data, and Validation Web Page.

Folder structure

File/Folder	Description
/src/P452.cpp	C++ implementation of Recommendation ITU-R P.452-18
/src/maps/	Subfolder containing data maps provided with Recommendation ITU-R P.452 (see Integrating ITU Digital Products).
/tests/	Folder containing validation tests against the reference MATLAB/Octave implementation from ITU-R SG 3 Software, Data, and Validation Web Page

Integrating ITU Digital Products

This software uses ITU digital products that are integral part of Recommendations. These products must not be reproduced or distributed without explicit written permission from the ITU.

Download and extract the required maps to ./src/maps:

• From ITU-R P.452-18:
  • DN50.TXT
  • N050.TXT
• Ensure all files are placed in ./src/maps before running the code.

Function Call

Lb = tl_p452(maps, f, p, d, h, g, zone, htg, hrg, phit_e, phit_n, phir_e, phir_n, Gt, Gr, pol, dct, dcr, press, temp);

Required input arguments of function tl_p452

Variable	Type	Units	Limits	Description
maps	class P452DigitalMaps			Object containing all the digital maps (DN50, N050) necessary for computation
f	double	GHz	~0.1 ≤ f ≤ ~50	Frequency
p	double	%	0.001 ≤ p ≤ 50	Time percentage for which the calculated basic transmission loss is not exceeded
d	vector<double>	km	0 < max(d) ≤ ~10000	Terrain profile distances (in the ascending order from the transmitter)
h	vector<double>	m (asl)		Terrain profile heights
g	vector<double>	m (asl)		Clutter + Terrain profile heights
zone	vector<int>		1 - Coastal Land, 2 - Inland, 3 - Sea	Radio-climatic zone types
htg	double	m		Tx antenna height above ground level
hrg	double	m		Rx antenna height above ground level
phit_e	double	deg	-180 ≤ phit_e ≤ 180	Tx Longitude
phit_n	double	deg	-90 ≤ phit_n ≤ 90	Tx Latitude
phir_e	double	deg	-180 ≤ phir_e ≤ 180	Rx Longitude
phir_n	double	deg	-90 ≤ phir_n ≤ 90	Rx Latitude
Gt Gr	double	dBi		Tx/Rx antenna gain in the direction of the horizon saalong the great-circle interference path.
pol	int		pol = 1, 2	Polarization of the signal: 1 - horizontal, 2 - vertical
dct	double	km	dct ≥ 0	Distance over land from the Tx antenna to the coast along the great-circle interference path. To be set to zero for a terminal on a ship or sea platform.
dcr	double	km	dcr ≥ 0	Distance over land from the Rx antenna to the coast along the great-circle interference path. To be set to zero for a terminal on a ship or sea platform.
press	double	hPa		Dry air pressure.
temp	double	deg C		Air temperature.

Outputs

Variable	Type	Units	Description
Lb	double	dB	Basic transmission loss

Validation

Validation can be performed by compiling the code and runing the tests as follows

./build.sh

Software Versions

The code was tested and runs on:

• Apple clang version 4.0.0 (tags/RELEASE_400/final) on x86_64-apple-darwin22.6.0

Prerequisites

The code uses googletest for automatised testing.

References

• Recommendation ITU-R P.452

• ITU-R SG 3 Software, Data, and Validation Web Page

• MATLAB/Octave Implementation of Recommendation ITU-R P.452