GnssToolbox - Python package for GNSS learning

Installation

This package requires Python 3

Required packages :

• gpsdatetime - https://pypi.org/project/gpsdatetime/ (J. Beilin - ENSG)
• re
• math
• numpy
• copy
• time
• os
• json
• from operator import attrgetter

Installation is accomplished from the command line.

• From pypi

user@desktop$pip3 install pygnsstoolbox

• From package source directory

user@desktop$~/gnsstoolbox$ python3 setup.py install

For usage see gnsstoolbox cheatsheet and beamer slides shipped with the package.

Import modules

""" Ephemerides management """
import gnsstoolbox.orbits as orbits

""" GNSS data (rinex "o" files) """ 
import gnsstoolbox.rinex_o as rx

""" Processing tools (rotations, coordinate conversions...) """
import gnsstoolbox.gnsstools as tools

""" Code processing """
import gnsstoolbox.gnss_process as proc

""" Constantes utiles """
import gnsstoolbox.gnss_const as const

""" Corrections (troposphere, antennas...) """
import gnsstoolbox.gnss_corr as corr

gnss_const

orbits

Structure

Orbit class contains all orbits informations :

GPS/Galileo nav element (nav_element)

Glonass nav element (nav_element)

Sp3 precise orbit (Sp3Pos class)

Data loading

• Broadcast ephemerides loading (*.yyn ou *.yyg)

Orb = orbits.orbit()
Orb.loadRinexN('brdm1500.13p')  

• Precise ephemerides loading (*.sp3)

Orb = orbits.orbit()
Orb.loadSp3(['igs17424.sp3','igl17424.sp3','grm17424.sp3'])

or

Orb.loadSp3('igs17424.sp3') 

Data access

• Get broadcast ephemerides for a satellite at an instant mjd

Eph = Orb.getEphemeris(constellation,PRN,mjd)
try:
	print("TOC : ",Eph.tgps.st_iso_epoch())
except:
	print("Unable to find satellite")	

• Get all precise ephemerides for a satellite

(orb,nl) = Orb.getSp3('G',5) 

# Satellite GPS, PRN 5
# 'G' : GPS, 'E' : Galileo, 'R' : Glonass

X = orb[:,1] # X coordinates at all sp3 epochs
Y = orb[:,2]
Z = orb[:,3]

Satellite coordinates/clock processing

• Process of ECEF coordinates and clock error (dte) for a satellite given by its constellation ('G','E','R'), its PRN, an instant mjd and et possibly a degree for Lagrange processing (precise orbits).

X, Y, Z, dte = Orb.calcSatCoord(const,PRN,mjd,degree)

A debug class object is implemented during coordinate processing. It contains all intermediaries results.

In order to get its attributes :

print(Orb.debug.__dict__)

• Process satellite clock error for a satellite given by its constellation ('G','E','R'), its PRN and an instant mjd.

dte = Orb.calcDte(const, PRN, mjd)

• Process satellite relativistic error for a satellite given by its constellation ('G','E','R'), its PRN and an instant mjd.

dt_relat = Orb.calcDtrelatNav(const, PRN, mjd)

Rinex_o

Structure

class rinex_o

class header

class epoch

class sat

Data loading

Loading observation Rinex file (*.yyo)

Rnx = rx.rinex_o()
Rnx.loadRinexO('smne1500.13o') 

Data access

• Get epoch object for a given MJD :

t=gpst.gpsdatetime()
t.rinex_t('13  5 30  1  0 30.0000000')
Ep = Rnx.getEpochByMjd(t.mjd)

• Get header object for a given MJD :

Hd = Rnx.getHeaderByMjd(t.mjd)

• Get attribute from any header

X0 = Hd.X

• Print all header or epoch informations

print(Hd)
print(Ep)

• Get any observable from an epoch :

C1 = Ep.getObs("C1","G", 31)

or

S = Ep.getSat("G", 31)
C1 = S.getObs("C1")

or (only for C/A code)

C1 = Ep.getSat("G", 31).C1

• Get all common data for 2 datasets at a given MJD

Ep_base,Ep_rover = rinex_base.getCommonEpochs(rinex_rover, 56442)

gnsstools

• toolGeoCartGRS80 : geographic to cartesian coordinates conversion. All angles should be given in radians.

X,Y,Z = tools.toolGeoCartGRS80(lon,lat,h)

• toolCartGeoGRS80 : cartesian to geographic coordinates conversion. All angles are given in radians.

lon,lat,h = tools.toolCartGeoGRS80(X,Y,Z)

• toolCartLocGRS80 : cartesian to topocentric coordinates conversion.

x, y, z = tools.toolCartLocGRS80(X0,Y0,Z0,X,Y,Z)

• toolAzEle : azimut and elevation (radians) for one or several satellites Xs,Ys,Zs (scalar or vector) seen from a point with X,Y,Z coordinates.

Az, Ele = tools.toolAzEle(X,Y,Z,Xs,Ys,Zs)

• toolAzEleH : azimut, elevation (radians) and ellipsoidal height for one or several satellites Xs,Ys,Zs (scalar or vector) seen from a point with X,Y,Z coordinates.

Az, Ele, h = tools.toolAzEleH(X,Y,Z,Xs,Ys,Zs)

• toolRotX, toolRotY, toolRotZ : alpha radians rotation around X, Y ou Z axis.

X,Y,Z =  tools.toolRotX(X,Y,Z,alpha)

• matCart2Local : matrix from cartesian to local coordinates. Longitudes and latitudes given in radians.

R =  tools.matCart2Local(lon, lat)

gnss_process

• TrilatGps : trilateration with 4 parameters (X,Y,Z,cdtr)

X,Y,Z,cdtr,sigma0_2,V,Qxx = trilatGps(PosSat,Dobs,X0)

• TrilatGnss : trilateration with 4, 5 or 6 parameters (X,Y,Z,cdtr,[cGGTO,cGPGL])

X,Y,Z,cdtr,cGGTO,cGPGL,sigma0_2,V,Qxx =  trilatGnss(PosSat,Dobs,X0,sat_index)

• TrilatGnssPonderationElev : trilateration with 4, 5 or 6 parameters (X,Y,Z,cdtr,[cGGTO,cGPGL]) avec with weighting given from elevation of each satellite.

X,Y,Z,cdtr,cGGTO,cGPGL,sigma0_2,V,Qxx =  trilatGnssPonderationElev(PosSat,Dobs,X0,sat_index,ElevSat)

Licence

Copyright (C) 2014-2025, Jacques Beilin - ENSG-Geomatics

Distributed under terms of the CECILL-C licence.