gnss-sdr/utils/skyplot

GNSS Skyplot utility

A Python script that generates polar skyplots from RINEX navigation files, showing satellite visibility over time.

Features

• Processes RINEX navigation files.
• Calculates satellite positions using broadcast ephemeris.
• Plots satellite tracks in azimuth-elevation coordinates.
• Color-codes satellites by constellation (GPS, Galileo, GLONASS, BeiDou).
• Customizable observer location.
• Outputs high-quality image in PDF format.
• Non-interative mode for CI jobs (with --no-show flag).

Requirements

• Python 3.6+
• Required packages:
  • numpy
  • matplotlib

Usage

Basic Command

./skyplot.py <RINEX_FILE> [LATITUDE] [LONGITUDE] [ALTITUDE] [--no-show]

Arguments

Argument	Type	Units	Description	Default
RINEX_FILE	Required	-	RINEX nav file path	-
LATITUDE	Optional	degrees (°)	North/South position	41.275°N
LONGITUDE	Optional	degrees (°)	East/West position	1.9876°E
ALTITUDE	Optional	meters (m)	Height above sea level	80.0 m
--no-show	Optional	-	Do not show plot	-

Examples

• Skyplot from default location (Castelldefels, Spain):

  ./skyplot.py brdc0010.22n
  

• Skyplot from custom location (New York City, USA):

  ./skyplot.py brdc0010.22n 40.7128 -74.0060 10.0
  

• Skyplot from custom location (Santiago, Chile):

  ./skyplot.py brdc0010.22n -33.4592 -70.6453 520.0
  

• Non-interactive mode (for CI jobs):

  ./skyplot.py brdc0010.22n -33.4592 -70.6453 520.0 --no-show
  

Output

The script generates a PDF file named skyplot_<RINEX_FILE>.pdf (with dots in <RINEX_FILE> replaced by _) with:

• Satellite trajectories over all epochs in the file.
• Color-coded by constellation.
• Observer location in title.
• Time range in footer.