OBJECTIVE

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CONVENTIONS
AND
MODELLING
FOR
REPRO3

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The final version of the repro3 reference frame SINEX file is now available at:
ftp://igs-rf.ign.fr/pub/IGSR3/IGSR3_2077.snx
ftp://igs-rf.ign.fr/pub/IGSR3/IGSR3_2077.ssc (without covariance matrix)
The associated discontinuity list and post-seismic deformation models are respectively available at:
ftp://igs-rf.ign.fr/pub/IGSR3/soln_IGSR3.snx
ftp://igs-rf.ign.fr/pub/IGSR3/psd_IGSR3.snx

Stations categorized by priority for Reference Frame Determination for repro3, provided by Paul Rebischung
Stations by priority
Antenna Information for each station
Receiver information for each station

The ANTEX file to be used for repro3 can be downloaded from igsR3_2077.atx

The antenna model was selected based on tests of different ANTEX files and assessing their impacts upon the reference frame for the period starting in 2017 through to the end of 2018

Test Reprocessing results from Paul Rebischung, with solutions provided by CODE, ESA, GFZ, GRG, and TuGraz

— should be implemented

• please also check for any ongoing electronic updates

As of early 2018, the IERS officially adopted a new (linear) mean pole for purposes of computing rotational deformation (pole tide). See the updated Chapter 7 at http://iers-conventions.obspm.fr/chapter7.php By adopting a linear mean pole, no corrections are required to C21/S21 going forward.

• only to be implemented during the reprocessing run. Do not implement this in the operational stream otherwise a discontinuity in the velocities will be introduced
• There is the possibility of applying this correction at the solution level, rather than at the observation level
• Here is a presentation by John Ries outling the case for a linear mean pole model here

HF-EOP recommends the use of the Desai&Sibois/Egbert model for diurnal and sub-diurnal EOP variation. Coefficients for this model and software to generate EOP predictions can be obtained from https://ivscc.gsfc.nasa.gov/hfeop_wg/

The SRP model to be applied is dependent upon the constellation, and satellite block being processed.
• ACs should upgrade from just ECOM1 modelling, with the exception of GPS Block IIF and IIR satellites
• ECOM2 or JPL GSPM modelling should be used for other GPS Block Types, or a box-wing model

Reflected (albedo) and retransmitted radiation from the Earth may cause scale (1 - 2 cm) and translational effects at GNSS altitudes; see:

• C.J. Rodriguez-Solano, 2009
• U. Hugentobleret al., 2009
• C.Rodriguez-Solano, 2011et al.

A recommended model for these effects,in the form of Fortran source code was originally developed within the scope of the IGS Orbit Modeling Working Group for repro2, this has recently been updated by Thomas Herring to include new values for GLONASS-M and GLONASS-K satellites (31 July 2019).
• ERPFBOXW.f Computation of Earth Radiation Pressure acting on a box-wing satellite
• SURFBOXW.f Computes the force on the satellite surfaces for a given radiation vector
• PROPBOXW.f Provides the satellite dimensions and optical properties for different satellites blocks:
  • GPS: GPS-I,GPS-II,GPS-IIA,GPS-IIR,GPS-IIR-A,GPS-IIR-B,GPS-IIR-M,GPS-IIF,GPS-IIIA
  • GLONASS: GLONASS-M,GLONASS-K
  • GALILEO: IOV, FOC

FES has recently been updated to FES2014b, a description of the products can be found here. A link to the spherical harmonic coefficients in geopotential be found at the bottom of the page.

Technicial note on satellite transmit power for GPS and GLONASS, by Peter Steigneberger is available from here

— recommend ACs apply all planets into model

Other ITRF observing techniques are considering the highest fidelity time-variable gravity model, this is not strictly required for GNSS orbits, but it will be important to stay consistent with their implementation.

— should be consistent with the TVG model, and again consistent across all observing techniques

Long Product Name Convention

use RINEX3 in preference to RINEX2 Provide solutions in updated SINEX formats that support RINEX3