List of parameters


A large number of parameter types are available in the Bernese GNSS Software for different (and potentially very specific) applications. They are listed below:


Station

  • Station Coordinates:
    Rectangular coordinates X, Y, Z in the ITRF (at present the ITRF2008 is used). The results are also expressed in the (user defined) geodetic datum (λ, β, h).
  • Station Velocities:
    In program ADDNEQ2, station velocities may be set up if a long time series of NEQ systems containing the same stations is available.
  • Epoch specific station coordinates:
    A set of station coordinates is assigned to each epoch (kinematic surveys).
  • Scaling factors:
    Scaling factors for up to three crustal deformation models provided in global grid files can be estimated to validate the model and/or to investigate the impact of the model on GNSS-derived parameters.
  • HELMERT-parameters:
    Transformation parameters (translation, rotation, scale) between the coordinate parameters from different normal equations can be estimated.


Clock

  • Receiver Clock Corrections:
    Estimation using code and phase zero-difference data (e.g., for time transfer) relative to a reference clock.
  • Satellite Clock Corrections:
    Estimation using code and phase zero-difference data.
  • Differential code biases:
    P1-P2 and P1-C1 code biases for receivers and satellites. Also, multipliers to verify the tracking technology of a receiver may be estimated.
  • GLONASS inter-frequency bias:
    Due to the different frequencies of the GLONASS signals from different satellites inter-frequency biases exist. Those are estimated when processing GLONASS zero-difference data.


Atmosphere

  • Station Specific Troposphere Parameters:
    Time- and station-specific zenith delay and gradient parameters may be introduced and solved for. High temporal resolution is possible, as well as reducing the number of parameters in ADDNEQ2.
  • Ionosphere Maps:
    Regional or global ionosphere single-layer maps may be determined. The electron density in the layer is described with spherical harmonics.
  • Scaling factors for higher order ionosphere terms:
    Scaling factors for each component of the higher order ionosphere terms (second and third order and ray banding) can be estimated to validate the input data for the HOI corrections and/or to investigate the influence of the corrections on GNSS-derived parameters.
  • Stochastic Ionosphere Parameters:
    Epoch- and satellite-specific ionosphere parameters may be introduced (together with a priori weights) to support ambiguity resolution.


Antenna

  • Satellite Antenna Phase Center Offsets:
    Such offsets may be assigned to different types of spacecraft (e.g., GPS Block IIA or Block-IIR, or GLONASS satellites).
  • Satellite Antenna Phase Center Variations:
    Phase patterns may be assigned to different types of spacecraft.
  • Receiver Antenna Phase Center Variations:
    Antenna phase center variations may be modeled using different techniques. Model parameters may be determined.
  • Mean Receiver Antenna Phase Center Offsets:
    May be estimated for antenna calibration experiments if site coordinates are accurately known.
  • GNSS-specific parameters:
    Biases for station coordinates and vertical troposphere between the observations from different GNSS may indicate deficiencies in the GNSS-specific receiver antenna calibration.


Orbit

  • Orbit Elements:
    Osculating orbital elements at initial time t0 of arc: semi-major axis a, eccentricity e, inclination i, right ascension of ascending node Ω, argument of perigee ω, and argument of latitude u0 at time t0.
  • Radiation Pressure Parameters:
    A total of nine parameters per satellite and arc may be introduced, three in each of three orthogonal directions (direction sun-satellite, solar panel axis, and normal to the first two). Constant and periodic once-per-revolution terms may be introduced.
  • Pseudo-Stochastic Orbit Parameters:
    Velocity changes in pre-determined directions at user-defined epochs may be introduced for each satellite. Up to three directions (e.g., radial, along-track, and out-of-plane) may be defined per epoch.
  • Earth Orientation Parameters:
    Polar motion (x and y components), UT1-UTC, nutation in obliquity and in longitude may be modeled. Only drifts may be estimated for the latter three parameter types. High time resolution is possible.
  • Center of Mass:
    The center of mass of the Earth may be estimated, which makes sense for global analyses.


Other

  • Phase Ambiguities:
    One initial phase ambiguity parameter has to be assigned to each (linearly independent) double difference. Resolved ambiguities may be introduced in subsequent program runs.
  • SLR range biases:
    SLR range biases can be introduced or estimated: one bias per station/satellite/group of satellites.