Miscellaneous results of flight calibration analysis Star fields and stellar calibrations: Relative geometry spacecraft cameras Intensity calibration Focus Comet LINEAR Straylight Flat fields (very quick look)

Relative pointing 0/2048 y 2048/2048 Prepixels amplifier A Prepixels amplifier B 0/0 2048/0 x S/c pointing direction on NAC: 1001,1051 S/c pointing direction on WAC: 1039, 962 NAC center on WAC: 1037, 954 WAC center on NAC: 1091, 1370

Intensity calibration Definition of calibration factor A = C/ I A: Calibration factor [DN s-1 / W m-2 nm-1 sterad-1] C: Count rate [DN s-1] I: Irradiance of the lamp [W m-2 nm-1 sterad-1] at the central wavelength of the filter combination

Results (WAC) Laboratory Standard Star

Results (WAC) Visible range: Stellar calibration comparable to Lab values Better internal consistency Discrepancy to theoretical expectations remains UV range: Unfortunately no good UV calibration < 330 nm available 375 and 388 are ok

Results (NAC) Laboratory Standard Star

Results (NAC) UV and near-IR: Everything (Star, lab, and theoretical prediction) consistent Visible: Stellar calibration ~ 20 % above Lab. Calibration, expectation in between Partly resolved by relative spectral response Partly unexplained Neutral density filter inconsistency remains

Significance of relative spectral response

Focus NAC: Star FWHM 1.4-2.1 pixels dependent on filter combination Exception: near focus plate expectedly out of focus (~ 3 pixels FWHM) Wings of PSF clearly visible in some filters WAC: FWHM 1.4-1.7 pixels dependent on filter combination

Focus WAC NAC

Unexplained effect in star fields Nearly (but not exactly) vertical stripes Meteors? Too dark, too large if at typical solar system velocity (kms/s) Spacecraft junk? Too dark, if resolved Extension of ~20 pixels difficult to explain, if unresolved Instrumental effect Consistent motion along field of view seen in 3 images Seen in 2 different filters WAC starfield from 5 June

Comet LINEAR Straylight with default filter combinations ~ 100 DN/s with the NAC ~ 200 – 2000 DN/s with the WAC Due to various anomalies at the end of slot 2 presentable images obtained with the NAC only Plasma tail clearly visible

Comet imaging Comet 2002 T7/LINEAR observed on 1 May 5 images in different colours with the NAC

OSIRIS NAC Multicolour Image Comet C/LINEAR 2002 T7 - 95 106 km distance – 1. May 2004

Images with internal lamps Visible: No changes to pre-flight on first look UV: Intensities (=leakage of visible/IR light) surprisingly high Dark current needs to be evaluated