p618PropagationLosses

Calculate Earth-space propagation losses, cross-polarization discrimination, and sky noise temperature

Since R2021a

Syntax

[pl,xpd,tsky] = p618PropagationLosses(p618cfg)

[pl,xpd,tsky] = p618PropagationLosses(p618cfg,Name,Value)

Description

[pl,xpd,tsky] = p618PropagationLosses(p618cfg) returns Earth-space propagation losses pl, cross-polarization discrimination xpd, and sky noise temperature tsky, as defined in the ITU-R P.618 recommendation [1]. p618cfg specifies the P.618 configuration parameters.

This function requires MAT-files with digital maps from International Telecommunication Union (ITU) documents. If they are not available on the path, download and uncompress the data files from https://www.mathworks.com/supportfiles/spc/P618/ITURDigitalMaps.tar.gz to a location on the MATLAB path.

example

[pl,xpd,tsky] = p618PropagationLosses(p618cfg,Name,Value) specifies additional options using one or more name-value pair arguments.

Examples

collapse all

Calculate Propagation Losses, Cross-Polarization Discrimination, and Sky Noise Temperature

Open Live Script

This example requires MAT-files with digital maps from ITU documents. If they are not available on the path, execute the following commands to download and unzip the MAT-files.

maps = exist('maps.mat','file');
p836 = exist('p836.mat','file');
p837 = exist('p837.mat','file');
p840 = exist('p840.mat','file');
matFiles = [maps p836 p837 p840];
if ~all(matFiles)
    if ~exist('ITURDigitalMaps.tar.gz','file')
        url = 'https://www.mathworks.com/supportfiles/spc/P618/ITURDigitalMaps.tar.gz';
        websave('ITURDigitalMaps.tar.gz',url);
        untar('ITURDigitalMaps.tar.gz');
    else
        untar('ITURDigitalMaps.tar.gz');
    end
    addpath(cd);
end

Create a default P.618 configuration object.

cfg = p618Config;

Specify the time percentage of excess for the rain attenuation per annum as 0.01 and the time percentage of excess for the total attenuation per annum as 0.001.

cfg.RainAnnualExceedance = 0.01;
cfg.TotalAnnualExceedance = 0.001;

Calculate the propagation losses, cross-polarization discrimination, and sky noise temperature.

[pl,xpd,tsky] = p618PropagationLosses(cfg)

pl = struct with fields:
    Ag: 0.2269
    Ac: 0.4552
    Ar: 6.7981
    As: 0.2633
    At: 15.6091

xpd = 32.8876

tsky = 267.4689

Calculate Earth-space Propagation Losses Using Name-Value Pair Arguments

Open Live Script

This example requires MAT-files with digital maps from ITU documents. If they are not available on the path, execute the following commands to download and untar the MAT-files.

maps = exist('maps.mat','file');
p836 = exist('p836.mat','file');
p837 = exist('p837.mat','file');
p840 = exist('p840.mat','file');
matFiles = [maps p836 p837 p840];
if ~all(matFiles)
    if ~exist('ITURDigitalMaps.tar.gz','file')
        url = 'https://www.mathworks.com/supportfiles/spc/P618/ITURDigitalMaps.tar.gz';
        websave('ITURDigitalMaps.tar.gz',url);
        untar('ITURDigitalMaps.tar.gz');
    else
        untar('ITURDigitalMaps.tar.gz');
    end
    addpath(cd);
end

Create a P.618 configuration object with a signal frequency of 20 GHz.

cfg = p618Config('Frequency',20e9);

Specify the surface water vapor density as 2.8 $\frac{g}{m^{3}}$ , the total columnar content of the cloud liquid water as 1.4 $\frac{kg}{m^{2}}$ , and the median value of the wet surface refractivity as 1.2. Set the earth station height as 0.5 km. Calculate the Earth-space propagation losses.

pl =  p618PropagationLosses(cfg,'StationHeight',0.5,...
                            'WaterVaporDensity',2.8,...
                            'TotalColumnarContent',1.4,...
                            'WetSurfaceRefractivity',1.2)

pl = struct with fields:
    Ag: 0.8649
    Ac: 1.0987
    Ar: 0.8907
    As: 0.1372
    At: 2.8590

Calculate Propagation Losses in Light Rainfall

Open Live Script

This example requires MAT-files with digital maps from ITU documents. If they are not available on the path, execute the following commands to download and unzip the MAT-files.

maps = exist('maps.mat','file');
p836 = exist('p836.mat','file');
p837 = exist('p837.mat','file');
p840 = exist('p840.mat','file');
matFiles = [maps p836 p837 p840];
if ~all(matFiles)
    if ~exist('ITURDigitalMaps.tar.gz','file')
        url = 'https://www.mathworks.com/supportfiles/spc/P618/ITURDigitalMaps.tar.gz';
        websave('ITURDigitalMaps.tar.gz',url);
        untar('ITURDigitalMaps.tar.gz');
    else
        untar('ITURDigitalMaps.tar.gz');
    end
    addpath(cd);
end

Create a P.618 configuration object that occupies a signal frequency of 20 GHz.

cfg = p618Config('Frequency',20e9);

Calculate the propagation losses in a light rainfall of 1 mm/hr with an earth station height of 0.75 km.

pl =  p618PropagationLosses(cfg,'RainRate',1,'StationHeight',0.75)

pl = struct with fields:
    Ag: 0.7996
    Ac: 0.8793
    Ar: 0.0177
    As: 0.3187
    At: 1.7514

Input Arguments

collapse all

`p618cfg` — P.618 configuration
p618Config object

P.618 configuration required for the calculation of the propagation losses, cross-polarization discrimination, and sky noise temperature, specified as a p618Config object.

Name-Value Arguments

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Before R2021a, use commas to separate each name and value, and enclose Name in quotes.

Example: 'StationHeight',1.5 specifies the earth station height as 1.5 km.

`StationHeight` — Height of earth station
nonnegative scalar

Height of the earth station above the mean sea level in km, specified as the comma-separated pair consisting of 'StationHeight' and a nonnegative scalar. The maximum supported value is 100. If the local data is not available as an input, the function uses the digital maps provided in ITU-R P.1511 section 1, Annex 1 [3] to obtain the station height value.