SOSM sensor model

sensor_model default

   response_limits <lower-wavelength> <upper-wavelength>

   response_curve
      wavelength <wavelength-value> <response>
      ...
   end_response_curve

   noise_equivalent_irradiance <power/area-value>

   detection_threshold <real-value>
   detection_threshold_above_horizon <real-value>
   detection_threshold_below_horizon <real-value>

   installation_adjustment_table <file-name>
   atmosphere <atmosphere-type>
   resolution <wavenumber-increment>
end_sensor_model

This page describes how to create a sensor definition for use with the Spectral Optical Sensing Model (SOSM). Each sensor definition must be contained in its own file. A sensor definition is made available to a simulation by using the sosm_interface load_sensor command.

Commands

response_limits <lower-wavelength> <upper-wavelength>

Defines the region in which the sensor can detect signals.

Default None - must be provided.

Example:

response_limits 3 um 5 um

response_curve … end_response_curve

wavelength <wavelength-value> <response>

The response_curve block defines the response of the sensor as a function of wavelength. The sensor model will use this curve to determine the response for the wavenumber bins.

Default Uniform response of 1.0

noise_equivalent_irradiance <power/area-value>

Default None - must be provided.

detection_threshold <real-value>

Default None - either this command or the detection_threshold_above/below_horizon command defined below must be provided.

detection_threshold_above_horizon <real-value>

detection_threshold_below_horizon <real-value>

Default None - either these commands or the detection_threshold command defined above must be provided.

installation_adjustment_table <file-name>

Specifies the name of a file which contains a table that defines a function whose independent variables are the azimuth and elevation of the target with respect to the sensing platform, and the dependent variable is a factor between 0 and 1 inclusive that used to scale the target irradiance. This is typically used to account for occlusion by structure or variable window transmittance.

The format of the file is as follows. The azimuth and elevation values are in degrees and the factors must be in the range between 0 and 1 inclusive. A value of 1 indicates the signal is passed unmodified, while a value of zero means the target is obscured by the structure or aperture. Intermediate values indicate partial obscuration.

*header-line-1*
*header-line-2*
*header-line-3*
*<number-of-az-values> <number-of-el-values>*
*      el1   el2   el3      eln*
*az1   f11   f12   f13      f1n*
*az1   f21   f22   f23      f2n*
*az1   f31   f32   f33      f3n*

*azm   fm1   fm2   fm3      fmn*

Default No installation adjustment.

atmosphere <atmosphere-type>

Default DEFAULT

resolution <wavenumber-value>

Default 20 cm-1

Example:

resolution 20 cm-1