Technical support
NGSO satellite calculations
Release number v1.0
Technical support
1. Introduction
The features described in this document are:
• Satellite/Station to satellite constellation…
• Satellite/Satellite constellation to station…
They are computing Earth to Space and Space to Earth interference to/from NGSO satellites and provide a
distribution of I/N values.
In all cases, the following box will be displayed that allows the user to enter the parameters of the
satellite constellation used in the I/N calculations:
2. Calculation parameters
Set up the constellation parameters:
Number of satellites: Total number of satellites in the constellation.
Number of plan: Number of orbital plans used by the constellation.
Pass number: The positions of the satellites are considered for calculations every (Period/Number of
passes) seconds.
Period in seconds: Duration of the analysis of the constellation.
Orbit tilt in degrees: Inclination or the orbital plane with respect to the equatorial plane.
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Phasis in degrees: If the phase is set to 0°, the different satellites of the constellation are uniformly
distributed every (360°/Number of planes) on each plane. Otherwise, they are distributed with a shift
of this phase.
Rain intensity 0.01% in mm/h, Vapour concentration in g/m3 and Temperature in Kelvin are used by
ITU-R P.618 propagation model.
Reference satellite: Selects a satellite from the database and attach it to the constellation.
Regarding propagation calculations, only ITU-R P.618 model is considered, without diffraction, leading
then to a worst case in terms of interference levels received.
It is anyway possible to introduce more losses in the propagation attenuations by using:
- Add. Losses in the station parameters;
- User attenuation instead of ITU-R P.618 in the satellite parameters:
3. Controls
: Access to the Interference rejection factors box (Interference rejection factors box.pdf,
http://www.data.atdi-group.com/doc/134.pdf).
: Loads a .618 file containing the constellation parameters previously saved.
: Saves the constellation parameters in a .618 file.
: Confirms the input, closes the box and runs the calculation.
: Closes the box without validation and stops the calculation procedure.
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4. Results
At the end of the calculation, a graphical distribution of I/N values will be displayed.
• Satellite/Station to satellite constellation…: The result will show the interference level
produced by activated stations on the map, on a constellation of satellites.
For each sample from 1 to “Pass number” passes, the I/N level is displayed.
For the total number of passes, the percentage of samples >, < and = to the specified I/N value
is also shown.
Inverted: If checked, the graphic will display the number of samples for each I/N value
considered.
“List”: it opens a Report box giving for each station and for each pass:
- the position of the satellite (latitude, Longitude, azimuth and elevation)
- the rain attenuation on that position
- the power received from the activated stations
- the frequency.
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• Satellite/Satellite constellation to station…: The result will show the interference level
produced by a constellation of satellites on activated stations on the map.
For each sample from 1 to “Pass number” passes, the I/N level is displayed.
For the total number of passes, the percentage of samples >, < and = to the specified I/N value
is also shown.
Inverted: If checked, the graphic will display the number of samples for each I/N value
considered.
“List”: it opens a Report box giving for each station and for each pass:
- the position of the satellite (latitude, Longitude, azimuth and elevation)
- the rain attenuation on that position
- the power received from the satellite
- the frequency.
Technical support NGSO satellite calculations - 5/5
