Atmosphere

The Atmosphere settings cover the following options:

• Ionosphere Settings
• Troposphere Settings

The settings which apply for both Ionosphere and Troposphere is the atmospheric attenuation.

Parameter	Description
Atmospheric attenuation	Atmospheric attenuation of satellite signals in [dB].

NOTE

Default values are provided for both ionospheric and tropospheric delays. The according computational model is freely selectable.

Ionosphere

Parameter	Description
Import Model from File	Imports model parameters from a RINEX navigation message file. If the header contains ionospheric correction entries for multiple GNSS systems only one model is imported. This example shows GPS and BEIDOU ionospheric parameters for the Klobuchar model. Only the first parameters (GPS) will be imported. Note: the read parameters are sorted internally by their GNSS system (satflag) and can differ from the order in the RINEX file.
Ionosphere Model	Determines which computational model is used by the simulation. Klobuchar NeQuick IONEX TEC maps

See Ionosphere models for a detailed list of utilized models.

The Ionosphere model selected in the drop-down Ionosphere Model is used as computational base when computing Ionosphere delays in the simulation. Depending on the model chosen, automatic conversion to other models is not always available:

Model	Description
Klobuchar	Klobuchar parameters are automatically converted to NeQuick and vice versa. NOTE: IONEX TEC maps are not changed, when Klobuchar or NeQuick parameters are changed.
NeQuick	NeQuick parameters are automatically converted to Klobuchar and vice versa. NOTE: IONEX TEC maps are not changed, when Klobuchar or NeQuick parameters are changed.
IONEX TEC maps	Ionex TEC maps are only used for delay computation. When a model is loaded from a file, Klobuchar & NeQuick parameters are automatically derived from the Ionex TEC maps.

Model Parameters

The Ionosphere model parameters can be set here. Depending on the selected model, only one table is available:

Parameter	Description
Klobuchar Parameters	Ionosphere parameters for the Klobuchar Ionosphere Model: : hold the Klobuchar coefficients. : hold the Klobuchar coefficients.
NeQuick Parameters	Ionosphere parameters for the NeQuick Ionosphere Model: a0 - a2: the effective ionisation level 1st-3rd order parameters. SF1 - SF5: the ionospheric disturbance flags for region 1-5.
IONEX TEC maps	Ionosphere TEC maps utilized internally by Global Ionsphere Maps (GIM)

See Ionosphere models for a detailed list of utilized models.

Noise

Parameter	Description
Apply Noise	Determines, whether AWGN is applied to ionosphere-based delays.
Noise σ [m]	The standard deviation of the normal distribution.

Troposphere

Parameter	Description
Set Parameters manually	If enabled, parameters for the chosen troposphere model can be set manually. Otherwise a fixed internal model is used.
Troposphere Model	Available models are: Hopfield Galileo Reference GPT2w Saastamoinen

See Troposphere models for a detailed list of utilized models.

Hopfield

Parameter	Description
Temperature [°C]	Temperature
Atmospheric Pressure [mbar]	Air pressure
Humidity [%]	Relative Humidity
Heigth Polytropic Layer Wet [km]	Height of polytropic wet layer

Galileo Reference

Parameter	Description
Temperature [°C]	Temperature
Atmospheric Pressure [mbar]	Air pressure
Humidity [%]	Relative Humidity

GPT2w

Parameter	Description
Temperature [°C]	Temperature
Atmospheric Pressure [mbar]	Air pressure
Humidity [%]	Relative Humidity
Grid Cell Size [° x °]	Grid cell size in [°] of the grid file. Supported values are [1°, 5°]

Saastamoinen

Parameter	Description
Temperature [°C]	Temperature
Atmospheric Pressure [mbar]	Air pressure
Humidity [%]	Relative Humidity

Noise

Parameter	Description
Apply Noise	Determines, whether AWGN is applied to troposphere-based delays.
Noise σ [m]	The standard deviation of the normal distribution.