IONO_ESTIMATOR
Below is an example of the IONO_ESTIMATOR block:
[IONO_ESTIMATOR]
UNCORRECTED_IONO_DELAY_MEAN = 7.25
UNCORRECTED_IONO_DELAY_STD = 2.5
KLOBUCHAR_ZENITH_IONO_DELAY_STD = 3.9
NTCMG_ZENITH_IONO_DELAY_STD = 1.8
IONO_DELAY_STD_INFLATION_FACTOR = 1.0
UNCORRECTED_IONO_DELAY_MEAN
Default: 7.25
Parameter Class: Tunable
Impact of Change: Low
Technical Info: Fallback ionospheric delay correction, in meters-equivalent delay at the L1 frequency. Used only when ionosphere correction is enabled but no SBAS, NTCM-G, or Klobuchar data is available.
Practical Tuning Info: Leave at the default in almost all cases.
UNCORRECTED_IONO_DELAY_STD
Default: 2.5
Parameter Class: Tunable
Impact of Change: Low
Technical Info: Assumed standard deviation, in meters-equivalent delay at the L1 frequency, of the fallback ionospheric delay estimate when no ionosphere model is available. This uncertainty is added to the measurement model so pseudorange measurements are weighted less strongly when ionospheric error is not well known.
Practical Tuning Info: Leave at the default in almost all cases.
KLOBUCHAR_ZENITH_IONO_DELAY_STD
Default: 3.9
Parameter Class: Tunable
Impact of Change: Low
Technical Info: Assumed zenith-delay uncertainty, in L1-equivalent meters, used when the Klobuchar ionosphere model is available. PpRx computes the ionospheric delay from the broadcast Klobuchar parameters, then uses this value to estimate how much residual error may remain after correction.
Practical Tuning Info: Leave at the default for typical broadcast Klobuchar correction. Increase this value when the Klobuchar model is expected to be less reliable, such as during high ionospheric activity.
NTCMG_ZENITH_IONO_DELAY_STD
Default: 1.8
Parameter Class: Tunable
Impact of Change: Low
Technical Info: Assumed zenith-delay uncertainty, in L1-equivalent meters, used when the NTCM-G/NeQuick ionosphere model is available. PpRx computes the ionospheric delay from the broadcast NTCM-G/NeQuick parameters, then uses this value to estimate how much residual error may remain after correction.
Practical Tuning Info: Leave at the default for typical broadcast NTCM-G correction. Increase this value when the NTCM-G model is expected to be less reliable, such as during high ionospheric activity.
IONO_DELAY_STD_INFLATION_FACTOR
Default: 1.0
Parameter Class: Tunable
Impact of Change: Medium
Technical Info: Global multiplier applied to the ionospheric delay uncertainty from any ionosphere path, including uncorrected fallback, Klobuchar, NTCM-G/NeQuick, and SBAS. Higher values make the estimator treat pseudorange measurements as less certain due to ionospheric activity.
Practical Tuning Info: Leave at 1.0 for most cases. This value can be increased (e.g. up to 2) for periods of high ionospheric activity.
When multiple ionosphere models are available, PpRx uses the first model that can provide a correction in the following order: SBAS, NTCM-G/NeQuick, Klobuchar, then the uncorrected fallback values.