Single-slit response functions

Single slit response functions The single-slit response functions used for analysing the star mapper transit data were constructed per passband, slit group, field of view and upper- and lower branch of the slit group. The coding is as follows:

  • Slit group, I: iChevron (inclined); V: vertical
  • Branch, L: lower, U: upper
  • Field of view, P: preceding, F: Following

Charts are organized per field of view, and per channel. The profiles are normalize to give a response 1.0 at the centre of the curve. Curves have been determined for 18 time intervals over the mission. The chart above shows the results for 6 of these, distributed over the mission.

The profiles for the inclined slits are always wider than for the vertical slits.

SSRF derivatives Next to the profiles, also the derivatives for the first time interval are shown, again organized in the same way. Here the vertical slits are in blue, the inclined slits in red. The derivatives play a crucial role in the determination of the transit time of the image.