GPS SP3 files not updating on CDDIS

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russelan
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Joined: Tue Aug 30, 2022 10:23 am America/New_York
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GPS SP3 files not updating on CDDIS

by russelan » Tue Nov 29, 2022 1:34 pm America/New_York

The GPS SP3 Ultrarapid and Rapid products that are stored at https://cddis.nasa.gov/archive/gnss/products/ have not been updated since 2022:11:27 21:05:03 UTC. Usually these files are uploaded at a consistent cadence. Does anyone know of when this will be resolved or if this data is now being hosted at a different location?

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russelan
Posts: 3
Joined: Tue Aug 30, 2022 10:23 am America/New_York
Answers: 0

Re: GPS SP3 files not updating on CDDIS

by russelan » Wed Nov 30, 2022 2:12 pm America/New_York

I have resolved my issues with this data. Here is what I found in case others run into the same issue.

IGS is adopting a new coordinate frame (IGS20) and file naming scheme as seen in this announcement: ​https://igs.org/news/igs20/.

As part of this change they are modifying the file naming scheme used for the GPS SP3 files (​http://acc.igs.org/repro3/Long_Product_Filenames_v1.0.pdf). The GPS week and day of week in the file name have been replaced by UTC year and day of year.

Example previous Rapid name:
igr22380.sp3.Z
Example new Rapid name:
IGS0OPSRAP_20223310000_01D_15M_ORB.SP3.gz

Example previous Ultrarapid name:
igu22380_06.sp3.Z
Example new Ultrarapid name:
IGS0OPSULT_20223310600_02D_15M_ORB.SP3.gz

The project I am working on saw a negligible difference in the results with the change in the coordinate frame. For GPS weeks 2222-2237, you can use data in https://cddis.nasa.gov/archive/gnss/products/WWWW/igs20/ (where WWWW is the GPS week) to compare the IGS20 coordinate frame data with the previous system.

CDDIS might need to update this page to reflect the new naming scheme:
https://cddis.nasa.gov/Data_and_Derived_Products/GNSS/orbit_products.html

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