Last December we introduced the new module COMP to compare satellite orbits. As from today you can also compare satellite clocks and station coordinates using COMP.

As in the case of orbits, clocks from ODTS (estimated and predicted) can be compared to IGS products (only rapid and final clocks, but not ultra-rapid ones yet, sorry). IGS rapid and final clocks are automatically downloaded and stored on the magicGNSS server. Rapid IGS clocks have a latency of around 2 days and final clocks have a latency of nearly two weeks. When comparing with IGS clocks, COMP tries always to choose the final IGS clock, and if it is not available it chooses the rapid one instead.

IGS clocks use the IGS Time Scale (IGST) as reference, whereas ODTS “fixes” the Reference Clock (a station) to zero and refers all estimated clocks to the Reference Clock. Then, in order to compare IGS and ODTS clocks, we propose the following two methods on the Settings tab:

The fist method is selected by default and normally gives slightly better results than the second one. If all goes well you should get typical ODTS vs IGS clock comparisons of the order of 0.2 ns (RMS).

You can also compare clocks (estimated and predicted) between two different ODTS scenarios. Estimated station coordinates from two different ODTS scenarios can also be compared with COMP.

This entry was posted on Friday, February 13th, 2009 at 7:57 pm and is filed under Announcements, Tips & Tricks. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.