Figures and Statistics for Precise Point Positioning (PPP)

PPP Strategy:
A Precise Point Positioning (PPP) is performed using the ERPs, SP3 orbits, and satellite clocks from the IGS Final/Rapid combination as well as from the individual contributing Analysis Centers. Clocks and RINEX observations are decimated to 5-min intervals.

The PPP is done on a daily basis for each of the available stations defining the IGS Reference Frame ( 274 stations for IGS14). For each set of AC orbits, ERPs, and satellite clocks, a PPP solution is done in three steps. Step 1 involves fitting the satellite positions from the SP3 orbit files to the extended CODE (6+9) orbit model using the associated ERPs in the ECF->Inertial transformation. Step 2 involves preprocessing of the clocks and RINEX observations to detect and eliminate clock jumps and cycle slips. Step 3 is the data reduction with iterative post-fit cleaning; outliers in the phase residuals are taken to be greater than 25 mm and outliers in the code residuals are taken to be greater than 2.5 m. A-priori modeling of the tropospheric delay is done using the Global Mapping Function (GMF) and Global Pressure and Temperature (GPT) model. Prior to 11 April 2013, The Niell Mapping Function (NMF) and standard meteorological data were used. The products from each AC are processed seperately; this way the cleaning for one AC has no effect on the results for the other ACs.

Helmert transformations are performed between the global network compiled from the PPP results and both the IGS Reference Frame and the IGS combined SINEX solution. The Helmert transformation parameters and station residual statistics are given over the past 7 days. North, east, up residuals (after the Helmert transformation) for each of the stations are presented including its mean and standard deviation over the past 7 days.

The PPP results give a measure of the internal consistency for each set of AC clocks, orbits, and ERPs. Over time, the PPP analysis also reveals information about the stability of station coordinates and the realization of a given reference frame.

Starting on 19-Aug-2012 (GPS Week 1702; mjd=56158), the IGS Finals products switched from being based on weekly SINEX integrations to being based on daily ones. Associated with this switch is a change to comparing with daily SINEX files, instead of a weekly one. The switch began impacting the Rapid PPP starting on 05-Sep-2012 (GPS Week 1704, day 3; mjd=56175).

Software:
Bernese GNSS Software v. 5.2, Developed by the Astronomical Institute of the University of Bern, Switzerland
(Bernese v. 5.0 was replaced on 11 April 2013)

PPP using Rapid Orbits and Clocks

PPP Rapid Transformations recent weeks GIF PS history GIF PS
PPP Rapid Rotations and Scales recent weeks GIF PS history GIF PS
PPP Rapid Station RMS
(IGS RF)		 recent weeks GIF PS history GIF PS
PPP Rapid Station RMS (SINEX irf) recent weeks GIF PS history GIF PS


PPP using Final Orbits and Clocks

All AC and IGR/IGS results in one plot for each component.

Trans. Rot.
GIF recent weeks Scale X Y Z X Y Z history Scale X Y Z X Y Z
PS recent weeks Scale X Y Z X Y Z history Scale X Y Z X Y Z


PPP Final Station RMS (IGS RF) recent weeks GIF PS history GIF PS
PPP Final Station RMS (SINEX irf) recent weeks GIF PS history GIF PS


Figures for the individual ACs (and IGR/IGS).
Transformation parameters from the SINEX combinations are included for comparison.

Translations and Scale from:

GIF recent weeks cod emr esa gfz jpl mit igr igs history cod emr esa gfz jpl mit igr igs
PS recent weeks cod emr esa gfz jpl mit igr igs history cod emr esa gfz jpl mit igr igs


Rotations from:

GIF recent weeks cod emr esa gfz jpl mit igr igs history cod emr esa gfz jpl mit igr igs
PS recent weeks cod emr esa gfz jpl mit igr igs history cod emr esa gfz jpl mit igr igs


 

12 April 2013, originator IGS ACC