Python Implementation of Recommendation ITU-R P.1546-6

This code repository contains a python software implementation of Recommendation ITU-R P.1546-6 with a method for point-to-area predictions for terrestrial services in the frequency range 30 MHz to 4000 MHz.

This version of the code corresponds to the reference version of the code approved by ITU-R Working Party 3K and published on ITU-R SG 3 Software, Data, and Validation Web Page as digital supplement to Recommendation ITU-R P.1546.

The package can be downloaded and installed using:

python -m pip install "git+https://github.com/eeveetza/Py1546/#egg=Py1546"   

and imported as follows

from Py1546 import P1546

| File/Folder | Description | |----------------------------|---------------------------------------------------------------------| |/src/Py1546/P1546.py | python implementation of Recommendation ITU-R P.1546-6 | |/tests/validateP1546.py | python script used to validate the implementation of Recommendation ITU-R P.1546-6 in P1546.bt_loss() | |/tests/validation_profiles/ | Folder containing a proposed set of terrain profiles and inputs for validation of MATLAB implementation (or any other software implementation) 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 P1546.bt_loss can be called

1. by invoking only the first nine required input arguments:

E, Lb = P1546.bt_loss(f,t,heff,h2,R2,area,d_v,path_c,pathinfo);

2. by explicitly invoking all the input arguments:

E, Lb = P1546.bt_loss(f,t,heff,h2,R2,area,d_v,path_c,pathinfo, \
                         q,wa,PTx,ha,hb,R1,tca,htter,hrter,eff1,eff2,debug,fidlog)

3. or by explicitly omitting some of the optional input arguments:

Ep, Lb = P1546.bt_loss(f,t,heff,h2,R2,area,d_v,path_c,pathinfo, \
                       q,wa,PTx,[],[],[],[],[],[],[],[],debug,fidlog)

Required input arguments of function P1546.bt_loss

| Variable | Type | Units | Limits | Description | |-------------------|--------|-------|--------------|--------------| | f | scalar double | MHz | 30 ≤ f ≤ 4000 | Frequency | | t | scalar double | % | 1 ≤ p ≤ 50 | Time percentage for which the calculated basic transmission loss is not exceeded | | heff | scalar double | m | | Effective height of the transmitting/base antenna, height over the average level of the ground between distances of 3 and 15 km from the transmitting/base antenna in the direction of the receiving/mobile antenna.| | h2 | scalar double | m | | Receiving/mobile antenna height above ground level | | R2 | scalar double | m | | Representative clutter height around receiver. Typical values: R2=10 for area='Rural' or 'Suburban' or 'Sea', R2=15 for area='Urban', R2=20 for area='Dense Urban' | | area | string | | 'Land, 'Sea', 'Warm', 'Cald' | Area around the receiver.| | d_v | array double | km | sum(d_v) ≤ ~1000 | Array of horizontal path lengths over different path zones starting from transmitter/base station terminal.| | path_c | array string | | 'Land', 'Sea', 'Warm', 'Cold' | Array of strings defining the path zone for each given path lenght in d_v starting from the transmitter/base terminal. | | pathinfo | scalar int | | 0, 1 | 0 - no terrain profile information available, 1 - terrain information available |

Optional input arguments of function P1546.bt_loss

| Variable | Type | Units | Limits | Description | |-------------------|--------|-------|--------------|--------------| | q | scalar double | % | 1 ≤ q ≤ 99 | Location percentage for which the calculated basic transmission loss is not exceeded. Default is 50%. | | wa | scalar double | m | ~50 ≤ wa ≤ ~1000 | The width of the square area over which the variabilitiy applies. Needs to be defined only if pathinfo= 1 and q≠50. Default: 0 dB. | | Ptx | scalar double | kW | Ptx > 0 | Tx power; Default: 1. | | ha | scalar double | m | | Transmitter antenna height above ground. Defined in Annex 5 §3.1.1. Limits are defined in Annex 5 §3. | | hb | scalar double | m | | Height of transmitter/base antenna above terrain height averaged over 0.2d and d, when d is less than 15 km and where terrain information is available. | | R1 | scalar double | m | | Representative clutter height around transmitter. | | tca | scalar double | deg | 0.55 ≤ tca ≤ 40 | Terrain clearance angle.| | htter | scalar double | m | | Terrain height in meters above sea level at the transmitter/base.| | hrter | scalar double | m | | Terrain height in meters above sea level at the receiver/mobile.| | eff1 | scalar double | deg | | The h1 terminal's terrain clearance angle calculated using the method in §4.3 case a), whether or not h1 is negative.| | eff2 | scalar double | deg | | The h2 terminal's terrain clearance angle calculated using the method in §11, noting that this is the elevation angle relative to the local horizontal.| | debug | scalar int | | 0, 1 | If debug= 1, the results are written in log files. Default: 0. | | fidlog | 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 | |------------|--------|-------|-------------| | Ep | double | dB(uV/m) | Electric field strength | | Lb | double | dB | Basic transmission loss |

Notes

Notes: If sea path is selected for a t value less then 50% the default 10% table use is a cold sea path.

Not implemented in this version of the code:

• Annex 7: Adjustment for different climatic regions
• Annex 5, Section 4.3a): C_h1 calculation (terrain database is available and the potential of discontinuities around h1 = 0 is of no concern)

Software Versions

The code was tested and runs on:

• python3.9

References

• Recommendation ITU-R P.1546

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

• MATLAB/Octave Implementation of Recommendation ITU-R P.1546