/Py1812

Python Implementation of Recommendation ITU-R P.1812

Primary LanguagePythonGNU General Public License v3.0GPL-3.0

Python Implementation of Recommendation ITU-R P.1812

This code repository contains a python software implementation of Recommendation ITU-R P.1812-6 with a path-specific propagation prediction method for point-to-area terrestrial services in the frequency range 30 MHz to 6000 MHz.

This is a translation of the original reference MATLAB/Octave Implementation of Recommendation ITU-R P.1812 approved by ITU-R Working Party 3K and published by Study Group 3 on ITU-R SG 3 Software, Data, and Validation Web Page.

The package can be downloaded and installed using:

python -m pip install "git+https://github.com/eeveetza/Py1812/#egg=Py1812"

and imported as follows

from Py1812 import P1812
File/Folder Description
/src/Py1812/P1812.py python implementation of Recommendation ITU-R P.1812-6
/tests/validateP1812.py python script used to validate the implementation of Recommendation ITU-R P.1812-6 in P1812.bt_loss()
/tests/validation_profiles/ Folder containing a proposed set of terrain profiles and inputs for validation of software implementations of this Recommendation
/tests/validation_results/ Folder containing all the results written during the transmission loss computations for the set of terrain profiles defined in the folder ./validation_profiles/

Function Call

The function P1812.bt_loss can be called

  1. by invoking only the required input arguments:
Lb, Ep = P1812.bt_loss (f, p, d, h, R, Ct, zone, htg, hrg, pol, phi_t,  phi_r,  lam_t,  lam_r)
  1. by invoking both the required and optional input arguments (the latter can be invoked in any order as key = value pairs):
Lb, Ep = P1812.bt_loss(f, p, d, h, R, Ct, zone, htg, hrg, pol, phi_t, phi_r, lam_t, lam_r, \
            pL = val_pL, sigmaL = val_sigmaL, Ptx = val_Ptx, DN = val_DN, N0 = val_N0 \
            dct = val_dct, dcr = val_dcr, flag4 = val_flag4, debug = val_debug, fid_log = val_fid_log)

Required input arguments of function tl_p1812

Variable Type Units Limits Description
f scalar double GHz 0.03 ≤ f ≤ 6 Frequency
p scalar double % 1 ≤ p ≤ 50 Time percentage for which the calculated basic transmission loss is not exceeded
d array double km ~0.25 ≤ max(d) ≤ ~3000 Terrain profile distances (in the ascending order from the transmitter)
h array double m (asl) Terrain profile heights
R array double m Representative clutter heights
Ct array int 1 - Water/sea, 2 - Open/rural, 3 - Suburban, 4 - Urban/trees/forest, 5 - Dense urban Array of representative clutter types. If empty or all zeros, the default clutter type used is Open/rural
zone array int 1 - Sea, 3 - Coastal land, 4 - Inland Radio-climatic zone types
htg scalar double m 1 ≤ htg ≤ 3000 Tx antenna height above ground level
hrg scalar double m 1 ≤ hrg ≤ 3000 Rx antenna height above ground level
pol scalar int pol = 1, 2 Polarization of the signal: 1 - horizontal, 2 - vertical
phi_t scalar double deg -80 ≤ phi_t ≤ 80 Latitude of Tx station
phi_r scalar double deg -80 ≤ phi_r ≤ 80 Latitude of Rx station
lam_t scalar double deg -180 ≤ lam_t ≤ 180 Longitude of Tx station
lam_r scalar double deg -180 ≤ lam_r ≤ 180 Longitude of Rx station

Optional input arguments of function tl_p1812

Variable Type Units Limits Description
pL scalar double % 1 ≤ pL ≤ 99 Location percentage for which the calculated basic transmission loss is not exceeded. Default is 50%.
sigmaL scalar double dB location variability standard deviations computed using stdDev.m according to §4.8 and §4.10; the value of 5.5 dB used for planning Broadcasting DTT; Default: 0 dB.
Ptx scalar double kW Ptx > 0 Tx power; Default: 1.
DN scalar double N-units/km DN> 0 The average radio-refractivity lapse-rate through the lowest 1 km of the atmosphere at the path-center. It can be derived from an appropriate map. Default: 45.
N0 scalar double N-units The sea-level surface refractivity at the path-centre. It can be derived from an appropriate map. Default: 325.
dct scalar double km dct ≥ 0 Distance over land from the Tx antenna to the coast along the great-circle interference path. Default: 500 km. Set to zero for a terminal on a ship or sea platform.
dcr scalar double km dcr ≥ 0 Distance over land from the Rx antenna to the coast along the great-circle interference path. Default: 500 km. Set to zero for a terminal on a ship or sea platform.
flag4 scalar int If flag4= 1, the alternative method from Attachment 4 to Annex 1 is used to calculate Lbulls without using terrain profile. Default: 0.
debug scalar int If debug= 1, the results are written in log files. Default: 0.
fid_log scalar int Only used if debug= 1 File identifier of the log file opened for writing outside the function. If not provided, a default file with a filename containing a timestamp will be created.

Outputs

Variable Type Units Description
Lb double dB Basic transmission loss
Ep double dB(uV/m) Electric field strength

Software Versions

The code was tested and runs on:

  • python3.9

References