Good evening all,
I am fairly new to the use of Orekit and am unsure whether what I’m encountering is a general Orekit error or a Python wrapper error. I am currently attempting to use Orekit’s RinexNavigationParser to parse GALILEO navigation messages acquired from CDDIS before feeding them into some propagation algorithms. I was expecting a slight difference between the file itself and the extracted AbsoluteDate for time scale conversion. However, the AbsoluteDate’s extracted from each message are approximately 20 years into the future of each nav message’s epoch, e.g for ABPO00MDG_R_20213350000_01D_EN.rnx satellite ID E31, the epoch is 2021-11-30T23:30:00 at the first message but is ingested as 2041-07-16T23:29:42.000.
The code I am using to ingest the file and extract the appropriate GALILEO message is as copied below, inside a for loop not shown:
fp = os.path.join(sat_fp, file)
rnx_parser = navigation.RinexNavigationParser()
rnx_file = org.orekit.data.DataSource(fp)
parsed_rnx = rnx_parser.parse(rnx_file)
# Orekit raises an error if no data is found related to a given sat id
try:
sat_data = parsed_rnx.getGalileoNavigationMessages(sat_id)
except orekit.JavaError:
# Skip to next file if no data is found
continue
The RINEX version in this case is 3.04, and I’ve tested 2022 and 2021 GALILEO data; both show the approx. 20-year jump. I’ve attached two example RNX files for reference from the CDDIS database.
ABPO00MDG_R_20213350000_01D_EN.rnx (950.9 KB)
ABPO00MDG_R_20223350000_01D_EN.rnx (968.5 KB)
I appreciate any insight you all may be able to offer, either if this is a Python wrapper error, an Orekit error, or if I am not performing the ingestion correctly.
I’m happy to provide any more information that may be missing from this initial post.
Thank you for your help!