Atmospheric dispersion PSF Effect

[astronomyk]

The easiest way to apply the atmospheric dispersion will be to create a PSF cube where the kernel is offset by the amount of atmospheric dispersion relevant to each wavelength layer. This is especially needed for LSS modes where the AD causes the target to move out of the slit at certain wavelength when the slit is not aligned with the zenith.

• For the case of a FOV cube, the PSF cube should match the waveset of the FOV
• For the case of a FOV image, the PSF cube should use a waveset where the centre of the PSF is shifted by n*pixel_scale (where n=(0..1]). The PSF kernel cube should then be collapsed before being applied to the FOV image