Archive for October, 2009

Automating data processing with the Scheduler

October 21st, 2009 by Ricardo Píriz

With the latest version of magicGNSS (1.4), and if you have a *pro* account, you will be able to automate your station data processing in ODTS or PPP, using the new Scheduler. This is how the Scheduler settings look like:

Scheduler

Just select the algorithm you want to automate (ODTS or PPP). Previously you should have run an ODTS or PPP scenario to be used as template by the Scheduler. Every time it runs, the Scheduler reads the scenario Duration, the list of Stations, and the Settings, from the template scenario. Make sure your template scenario is properly configured! (more…)

About satellite clock interpolation

October 5th, 2009 by Ricardo Píriz

Starting on GPS Week 1406 (Dec 17, 2006), the International GNSS Service (IGS) publishes final GPS satellite clocks at a rate of 30 seconds, in addition to the usual 5-minute rate. These high-rate satellite clocks are very useful for Precise Point Positioning (PPP), the algorithm in magicGNSS that processes stand-alone station data to calculate the station position, clock, and tropo delay.

Using 30-sec satellite clocks as input for PPP, one can choose a 30-sec station data rate without having to interpolate the input satellite clock values. magicGNSS supports 30-sec and 5-min data rates in PPP. As from today, if you select a 30-sec data rate in PPP and final 30-sec satellite clocks are available from IGS, they will be used instead of 5-min clocks. Remember that IGS final products have a latency of 2 to 3 weeks.

Until now if you selected a 30-sec data rate in PPP, the input 5-min clocks from IGS had to be interpolated. Clock interpolation is a bad thing because the interpolated values do not reflect the true satellite clock behavior at the interpolation epochs. The following figures show the effect of clock interpolation on the CONZ clock estimation from PPP:

conz_clock_5min

5-min station clock from PPP (no interpolation)

conz_clock_30secInt

30-sec station clock from PPP (interpolation, WRONG!)

conz_clock_30sec

30-sec station clock from PPP (no interpolation)