gpsdatetime 1.0.45

Python GPS date/time management package

gpsdatetime - Python GPS date/time management package

This is a python library for GNSS date/time transformations

Usage

Initialize gpsdatetime object

import gpsdatetime as gpst

• init from current computer date/time

t = gpst.gpsdatetime()

• init from modified julian date

t=gpst.gpsdatetime(mjd=54605.678)

• init from decimal year (warning on time precision)

t=gpst.gpsdatetime(dy=2008.382417522245)

• init from GPS week and second of week

t=gpst.gpsdatetime(wk=1400, wsec=600700)

• init from usual time elements

t=gpst.gpsdatetime(yyyy=2016, mon=1, dd=7, h=3, min=5, sec=5)

• init from SINEX time string

t=gpst.gpsdatetime('16:004:46888')

• init from sinex date elements

t=gpst.gpsdatetime(yyyy=2016, doy=004, dsec=45677)

• init from iso time string

t=gpst.gpsdatetime('16:01:04T03:05:05Z')

• init from RINEX time string

t=gpst.gpsdatetime('18 10  9 12 20 45.00000')

or

t=gpst.gpsdatetime('2018 10  9 12 20 45.00000')

Update date/time

Several functions are provided in order to update date/time.

Function	Parameters	Purpose
just_now		update from current date/time
ymdhms_t	year, month, day+[hour/minute/second]	update with date
yyyyddds_t	year, day-of-year, second-of-day
gpswkd_t	GPS week, day of week
gpswks_t	GPS week, second of week
mjd_t	modified julian day
jd_t	Julian day
snx_t	'20:123:43200'	update with Sinex time string
rinex_t	'2018 10 9 12 20 45.00000'	update with Rinex time string
iso_t	'16:01:04T03:05:05Z'	update with iso time string
timestamp_t	'10/Aug/2023:09:33:43 +0000'	update with timestamp time string

Time calculations

• add 5 seconds (or substract 2s) to gpsdatetime object t

t += 5
t -= 2

• add x days, hour, seconds to current object

t.add_day(x)
t.add_h(y)
t.add_s(z)

• test wether t is before t1 or not

if t < t1:
    print('t before t1')

• duration between two time objects

t1 = gpst.gpsdatetime()
t2 = gpst.gpsdatetime()
Delta_t  = t2 - t1 # result in seconds

• set t object to current date at 0h00

t.day00()

• set t object to current week on sunday morning 0h00

t.wk00()

• set t object to beginning of current hour

t.h00()

• set t object to beginning of current minute

t.m00()

Get attributes

Attribute	Description	Unit
s1970	seconds from 01-01-1970 à 0h00Z	second
mjd	Modified Julian Date (MJD = JD – 2400000.5)	decimal days
jd	Julian Date	decimal days
jd50	Julian Date from J1950	decimal days
wk	GPS week	week I4
wsec	seconds in GPS week	float [0..604800]
yyyy	year (4 digits)	year I4 [1902..2079]
yy	year (2 digits)	year (I2)
mon	month number	I2 [1..12]
dd	day of month	I2 [1..31]
hh	hour	I2 [0..24]
min	minute	I2 [0..60]
sec	second	I2 [0..60]
doy	day of year (DOY)	I3 [1..366]
wd	day of week (DOW)	I1 [0..6]
dsec	second of day	float [0..86400]
dy	decimal year	float [0..366]
GMST	Greenwich Mean Sidereal Time	decimal hours
EQEQ	Equation of equinoxes	decimal hours
GAST	Greenwich Aparent Sidereal Time	decimal hours

y = t.yyyy
# y = 2020

Print time strings

• Return iso time string :

iso_t = t.st_iso_epoch()
# 2020-10-01T12:00:26Z 

or

iso_t = t.st_iso_epoch(2)
# 2020-10-01T12:00:26.00Z 

• Return Ephem (https://pypi.org/project/ephem/) time string : 2020/10/01 12:00:26.0

s = t.st_pyephem_epoch()

• Return Rinex time string : 2020 10 01 12 00 26.0000000

s = t.st_rinex_epoch()

• Return Sinex time string : 20:010:43226

s = t.st_snx_epoch()

• Return time stamp

s = t.st_timestamp_epoch()

• Print all date/time elements

print(t)
"""
gpsdatetime (version 1.0.38)
-----------------------------------------------------------------
s1970 : 1677283200.000000
YYYY_MM_DD : 2023/02/25  
HH:MM:SS : 00:00:00.000000000
GPS week : 2250
Day of week : 6 (SAT)
Second of week : 518400.000000000
Second of day : 0.000000000      
session : a
Modified Julian Date : 60000.000000  
Julian Date : 2460000.500000
YYYY : 2023  DOY : 056
GMST (dec. hour) : 10.306795
GAST (dec. hour) : 10.306635
Eq. of Equinoxes (dec. hour) : -0.000160
-----------------------------------------------------------------
"""

Installation

Installation is accomplished from the command line.

• From pypi

user@desktop$pip3 install gpsdatetime

• From package source directory

user@desktop:~/gpsdatetime$ python3 setup.py install

licence

Copyright (C) 2014-2023, Jacques Beilin / ENSG-Geomatique

Distributed under terms of the CECILL-C licence.