The following list of processing features and characteristics is only a selection on the very top level.

It is related to the usual processing steps and some selected product aspects.

(This list is available as pdf):

*RINEX*- Support of RINEX 2.x, 3.x, and 4.x
- Verification of the station name with respect to the filename
- Extended verification of the RINEX headers w.r.t. an internal station information list including receiver/antenna+radome type,

serial number, and antenna displacements. - Check the availability of antenna+radome phase center corrections
- Removal of observations of systems without system-specific receiver antenna corrections
- Automated exclusion of stations with equipment changes, or presenting a reduced data tracking, or with indicated data problems) when importing the data.

*Preprocessing*- Detection and handling of inconsistencies between code and phase data regarding the receiver clock
- Determination of unknown GLONASS frequency numbers
- Baseline selection with advanced conditions regarding GNSS, marginally observed satellites, and beneficial baselines for ambiguity resolution.
- Automated adjustment of the screening technology for the cycle slip detection and outlier rejection according to the baseline length
- Automated exclusion of data intervals with exceptionally high number of cycle slips
- Removal of satellites with unusual high number of data problems
- Automated detection of misbehaving stations/satellites based on post-fit residuals Ambiguity resolution
- Optimized multiple-step ambiguity resolution scheme with different algorithms according to the baseline length, even for very long baselines
- Ambiguity resolution for PPP introducing consistent phase biases
- Self-calibrating single-difference ambiguity resolution for GLONASS
- Consider 1/4-cycle biases resulting from the simultaneous tracking of GPS L2C and L2P signals with some receiver types
- Re-initialization of ambiguities resolution results for all or a specific GNSS Processing
- Double-difference network solution with correct correlations
- Zero-difference network solution solving for all receiver and satellite clock parameters (equivalent to a consistent double difference solution)
- Precise Point Positioning (PPP) with ambiguity resolution
- Multi-GNSS (GPS/GLONASS/Galileo/BeiDou/QZSS) solutions or single GNSS configurations for dual-frequency datasets
- Numerous parameter types can be setup at the same time; generation of normal equations without inversion
- Flexible observation sampling, in particular for epoch parameters

*Modeling*- Modeling of tides, subdaily Earth rotation, and nutation are conforming with IERS Conventions (2010)
- Interpolation of ocean tidal loading to 342 constituents (HARDISP) according to IERS Conventions (2010)
- S1/S2 atmosphere pressure loading tidal corrections
- Center of mass corrections for ocean and atmospheric tidal loading
- Use of various gravity fields easily implementable
- DE421 ephemeris series for planets as well as the gravitational effect of ocean and solid Earth tides in the orbit integrator (ORBGEN)
- Piece-wise linear troposphere parameter representation, with possibility to enforce continuous parameterization at session boundaries
- A priori model for hydrostatic component of troposphere (mapped with dry-GMF or VMF3 mapping function)
- Horizontal troposphere gradient parameters
- Introduction of (globally) estimated troposphere delays on normal equation level
- Ionosphere corrections from global or regional ionosphere maps
- Higher order ionosphere corrections (2nd and 3rd order and ray bending) including scaling factors

*Station motion modelling*- Post-seismic deformations are applied according to the ITRF specification
- Tools to use only linear velocities for a given interval to derive a linear velocity field
- Station motions corrections for plate motions, tides, and ocean tidal loading
- Geophysical deformation models can be introduced as grids and validated by estimating scaling factors

*Normal equation handling*- Geodetic datum definition including automated verification of the reference coordinates
- Efficient parameter transformation for various purposes (reduce the resolution of parameters in time; long-arc for orbit determination)
- Flexible management to select parameters for pre-elimination or deletion (e.g., exclusion of boundaries of the normal equation to

guarantee continuity or keep station dependent parameters for specific sites for collocation) - Manipulations of normal equations without inversion
- Adaption of a priori values for most of the parameters
- Selected parameters can be added to existing normal equations
- SINEX generation based on "normal equation" or "covariance" representation
- Computation of repeatability for parameters of the input normal equations
- Evaluation of the time series by program FODITS (Find Outliers and Discontinuities in Time Series, see PhD thesis Ostini, 2012)

*Antennas*- Import of antenna phase center corrections from ANTEX format
- Receiver and satellite phase center corrections can be considered for each frequency to be processed
- Antenna misalignment towards north may be considered (where applicable)
- Individual GNSS-specific as well as receiver antenna corrections can be introduced
- Receiver and satellite antenna phase center parameters can be estimated

*Orbit modeling and estimation*- Satellite orbits import from precise orbit files depending on the accuracy code
- Satellite attitude modelled according to the manufacturer specification (as far as known)
- Estimation of six initial orbital elements and a set of up to nine dynamical orbit parameters in different frames:
- ◦ Sun-oriented frame at the satellite center of mass
- ◦ Terminator defined frame at the satellite center of mass
- ◦ Flight direction oriented frame at the satellite center of mass

the elevation of the Sun above the orbital plane, and the satellite attitude mode - Macromodels for non-gravitational force modelling of LEO and GNSS satellites(direct Solar radiation and Earth Albedo effects)
- Estimation of stochastic pulses during the orbit integration based on precise orbit files
- Estimation of stochastic pulses or empirical accelerations from GNSS observation data during the orbit improvement
- Detection and determination of GNSS repositioning events

*LEO orbit determination*- Detailed non-gravitational force modelling (direct solar radiation pressure, Earth radiation pressure, air drag and lift)

based on satellite macro model - Flexible estimation of scaling factors for non-gravitational forces
- Zero-difference ambiguity resolution
- New BSW format for satellite attitude quaternions, including conversion program

- Detailed non-gravitational force modelling (direct solar radiation pressure, Earth radiation pressure, air drag and lift)
*Observation specific System Biases*- Support of multi-GNSS code bias handling using observation specific biases
- Estimation capability of multi-GNSS code biases including automated datum definition according to the IGS standards
- Support of system, receiver-satellite or frequency dependent observation code bias estimation
- Consider phase biases for PPP ambiguity estimation
- Verification of the tracking technology by estimating multipliers

*Clock product generation*- Combination of clock RINEX files
- Automated selection of a reference clock
- Extrapolation of series from clock RINEX file
- Phase-based interpolation of clock corrections to generate high-rate clock products

*Simulation of GNSS observations*- According to a given geometry (satellite orbits and station positions) GNSS observations can be computed
- Assumptions with respect to the noise level, receiver/satellite clocks, ionosphere, troposphere,

and cycle slips can be introduced - These synthetic data can be processed on zero-difference or double-difference level
- The correct integer ambiguity is known to be zero in case of ambiguity resolution tests

**Quick Links**

Features

- Overview

- Detailed features

- Typical Use

- Ready-to-use processing examples

- Technical description

- General dataflow

- User support

- V52 vs V54

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