
Laboratory for Atmospheric and Space Physics

Ground Calibration

The ground calibration of SIM consists of a number of component level activities that are combined to produce the SIM measurement equations, the flow diagram for this process is shown on the left. These activities include:

  1. Measurement of the SIM ESR optical efficiency at the NIST SIRCUS facility. This is an ongoing calibration activity that is conducted with SIM flight spare components.
  2. Establish the instrument’s wavelength scale using atomic lines of mercury and a Schott BG-20 glass filter that has it wavelength scale tied to the wavelength scale of the National Solar Observatory’s Fourier transform spectrometer at Kitt Peak Observatory.
  3. The transmission of the prism glass as a function of wavelength and polarization.
  4. Measurement of the spectrometer’s instrument function with a wavelength stabilized laser and ray tracing models.


Measurement Equation Block Diagram

Measurement Equation Block Diagram (click image to enlarge)