J.P. Halain – Centre Spatial de Liège HI straylight performances Design, pre-flight test data and in flight results J.P. Halain – Centre Spatial de Liège with J.M. Defise, E. Mazy, A Mazzoli - CSL (Belgium) D Moses, J Newmark, C Korendyke, D Socker - NRL (US) C. Eyles, R. Harrison, C Davis - UB, RAL (UK) March 2007 SECCHI Consortium Meeting - Paris

SECCHI Consortium Meeting - Paris Summary HI Instrument concept Main challenges HI Straylight requirements Instrument design (diffractive and reflective baffles) HI pre-flight performance measurements Spot and photometry results Sun-limb, off-pointing and out-FOV straylight results HI preliminary in-flight straylight results Off-pointing results Straylight pattern analysis In and out-FOV results March 2007 SECCHI Consortium Meeting - Paris

SECCHI Consortium Meeting - Paris HI Instrument Concept Main challenges: Faint detection capability (10-15 B0)  high stray-light rejection requirements Large FOV  specific optics Solar light Forward Baffle Internal Baffle HI 1 HI 2 March 2007 SECCHI Consortium Meeting - Paris

HI Straylight Requirements Major stray-light contributors Direct solar light (B0 !) Bright sources in and out FOV (Earth) Payload elements near the UFOV Background composed of F-corona, planets, stars, Earth and moon Stray-light requirements Instrument background straylight requirements: < 3x10-13 B/B0 for HI-1 < 10-14 B/B0 for HI-2 HI-1 HI-2 March 2007 SECCHI Consortium Meeting - Paris

HI Design – Forward Baffle Front baffle concept with the location of the HI-1 & 2 optical systems Intensity profiles measured with the 5-knive edge mock up in air and in vacuum, measured @CSL HI cascading knives-edges forward baffle computed efficiency March 2007 SECCHI Consortium Meeting - Paris

HI Design – Internal Baffle Internal baffle ray-tracing model Computed performance at HI-2 entrance (log) Straylight level in HI-1 and HI-2 (nominal orbit) March 2007 SECCHI Consortium Meeting - Paris

HI pre-flight performance measurement HI-A and HI-B flight models optical performances and end-to-end straylight verification NB: instrument axis at 3.65-arcdeg HI instrument Black enclosure Light source collimator March 2007 SECCHI Consortium Meeting - Paris

Pre-flight: HI-A In-field results HI-A spot measurements : (1 px = 13.5µm) 38.8µm < HI-1 RMS spot diameter < 54.3µm 31.5µm < HI-2 RMS spot diameter < 78.1µm Design values: 45µm < HI-1 < 67µm 105µm < HI-2 < 145µm Half Energy Spot Width [µm] NB: - photometry results of HI-A pre-flight calibration are limited by smearing - straylight results are limited by chamber background March 2007 SECCHI Consortium Meeting - Paris

Pre-flight: HI-B In-field results HI-B spot measurements : (1 px = 13.5µm) 37.9µm < HI-1 RMS spot diameter < 49.8µm 68.6µm < HI-2 RMS spot diameter < 164.8µm (border of FOV) Design values: 45µm < HI-1 < 67µm 105µm < HI-2 < 145µm Half Energy Spot Width [µm] HI-B Photometry HI-1B detector conversion: 30345 photon/DN@670nm HI-2B detector conversion: 52626 photon/DN@670nm March 2007 SECCHI Consortium Meeting - Paris

Pre-flight: HI-1B straylight (sun limb) Straylight verification with reference black panels and collimated laser beam @670nm Super Black Panel 130DN = 3∙10-13 B/B0 (at requirement level) Underscan columns = 126 DN B0 = 1.33 1013 DN =4 1017 ph 720s integration time Laser Beam (B0) 133DN = 5∙10-13 B/B0 127DN = 7.5 10-14 B/B0 Curtain Edge HI-1B image taken @CSL March 2007 SECCHI Consortium Meeting - Paris

Pre-flight: HI-1B straylight (off-pointing) 5∙10-13 B/B0 7.5∙10-13 B/B0 3∙10-13 B/B0 Ring appears 4∙10-11 B/B0 8∙10-12 B/B0 1.2∙10-11 B/B0 0.17 0.33 2∙10-9 B/B0 4∙10-12 B/B0 1.2∙10-12 B/B0 5∙10-7 B/B0 1.8∙10-10 B/B0 10-9 B/B0 0.5 0.66 1.0 March 2007 SECCHI Consortium Meeting - Paris

Pre-flight: HI-1B straylight (1-arcdeg) Ring pattern dominate diffractive pattern in HI-1 straylight Diffractive pattern Ring pattern Detail of HI-1B image taken @CSL , with collimated beam at 1.5-arcdeg from sun-limb direction March 2007 SECCHI Consortium Meeting - Paris

Pre-flight: HI-1B straylight (diffraction) 3.6∙10-11 B/B0 5∙10-7 B/B0 Detail of HI-1B image taken @CSL , with collimated beam at 1.5-arcdeg from sun-limb direction March 2007 SECCHI Consortium Meeting - Paris

Pre-flight: HI-1B straylight (out FOV) Various offset angles at border of HI-1 FOV (3.65 – 23.65-arcdeg) Ring pattern visible + other ghosts In FOV 2.5 3.5 4 4.5 5 4.1∙10-8 B/B0 5∙10-8 B/B0 4.6∙10-8 B/B0 5.5∙10-8 B/B0 4.6∙10-9 B/B0 1.5∙10-7 B/B0 24 25 26 27 30 4.2∙10-8 B/B0 3∙10-8 B/B0 4∙10-8 B/B0 2.4∙10-8 B/B0 1.1∙10-8 B/B0 March 2007 SECCHI Consortium Meeting - Paris

Pre-flight: HI-2B straylight (sun limb) At Requirement level: 1.2∙ 10-14 B/B0 Super Black Panel Super Black Panel 1.2∙ 10-13 B/B0 Laser Beam (B0) Earth occulter 1.5∙ 10-15 B/B0 Black enclosure HI-2B image taken @CSL March 2007 SECCHI Consortium Meeting - Paris

Pre-flight: HI-1&2B (sun limb) Laser Beam (B0) Combination of HI-1B and HI-2B images taken @CSL March 2007 SECCHI Consortium Meeting - Paris

Pre-flight: HI-2B straylight (out FOV) Various offset angles at border of HI-2 FOV (18.36 – 88.36-arcdeg) Internal baffle illuminated + ghosts 4.3∙10-8 B/B0 2.7∙10-8 B/B0 1.2∙10-10 B/B0 2.6∙10-8 B/B0 10 15 90 1.7∙10-8 B/B0 6.4∙10-10 B/B0 4.5∙10-10 B/B0 4.3∙10-8 B/B0 100 120 140 March 2007 SECCHI Consortium Meeting - Paris

First Flight Image – HI-1A 13-Dec-2006 Approximate Location of Sun Ecliptic Plane F-Corona Symmetric with Ecliptic March 2007 SECCHI Consortium Meeting - Paris

First Flight Image – HI-2A 13-Dec-2006 Inner Baffle Illuminated by Earthshine Approximate Location of Sun Earth Occulter Ecliptic Plane F-Corona Symmetric with Ecliptic March 2007 SECCHI Consortium Meeting - Paris

In-flight: HI-1A & B straylight (off pointing) Off-pointing 10-Jan-07 and 13-Jan-07 HI-1A 1.2∙10-12 B/B0 1.1∙10-11 B/B0 > 5∙10-10 B/B0 1.0 1.5 HI-1B 2∙10-12 B/B0 1.2∙10-11 B/B0 4.8∙10-10 B/B0 1.0 1.5 March 2007 SECCHI Consortium Meeting - Paris

In-flight: HI-1A straylight (off pointing) Off-pointing 30-Jan-07 9.8∙10-12 B/B0 5.3∙10-13 B/B0 8.2∙10-13 B/B0 4∙10-12 B/B0 3.5∙10-12 B/B0 5∙10-12 B/B0 0.24 0.5 1∙10-12 B/B0 1.9∙10-12 B/B0 7.9∙10-11 B/B0 6∙10-12 B/B0 1.1∙10-11 B/B0 5∙10-10 B/B0 0.75 1.0 1.5 March 2007 SECCHI Consortium Meeting - Paris

In-flight: HI-1 straylight comparison March 2007 SECCHI Consortium Meeting - Paris

In-flight: HI-1A straylight (1.5-arcdeg) 2∙10-10 B/B0 Diffractive pattern 7.9∙10-11 B/B0 Ring pattern > 5∙10-10 B/B0 1.5 Similar combination of diffractive and ring pattern as measured @CSL (instrument pointing during tests 13.65-arcdeg vs. in flight pointing 13.98-arcdeg) March 2007 SECCHI Consortium Meeting - Paris

HI-1 straylight: ring pattern analysis Ray-tracing model of HI-1 lens barrel shows that the 2 last retainers generate the ring pattern FOV border (3.65-arcdeg) FOV border - 3 arcdeg (0.65-arcdeg) March 2007 SECCHI Consortium Meeting - Paris

HI-1 straylight: ring pattern analysis (2) FOV border - 7 arcdeg FOV border - 10 arcdeg FOV border - 15 arcdeg FOV border - 20 arcdeg March 2007 SECCHI Consortium Meeting - Paris

In-flight: HI-1 straylight (out-FOV) Earth arriving close to the HI-1B FOV on beg. February 07 (before entering in FOV) confirms the preliminary analysis of ring pattern (no diffractive pattern in the ring) 30 26 HI-1 B (1-Feb-07) HI-1 B (3-Feb-07) March 2007 SECCHI Consortium Meeting - Paris

In-flight: HI-1 straylight in-FOV Similar ring straylight pattern with a bright star (in FOV), probably due to other similar parts of the lens barrel (ghost). TBC. 1.3∙10-12 B/B0 > 2∙10-9 B/B0 March 2007 SECCHI Consortium Meeting - Paris

In-flight: HI-2 straylight (out-FOV) The 5 oval edges are in the FOV and imaged. Preliminary explanation is Earth close behind instrument and illuminate internal baffles from rear HI-2 A (13-Dec-06) HI-2 B (15-Jan-07) 88,425 March 2007 SECCHI Consortium Meeting - Paris

In-flight: HI-2 straylight (in and out FOV) Earth crossed HI-2B FOV beg. of February 140 120 100 90 80 50 20 10 In FOV Earth behind instrument is not the only straylight sources in HI-2 (SWAVES boom ?) March 2007 SECCHI Consortium Meeting - Paris

SECCHI Consortium Meeting - Paris Conclusions Preliminary straylight comparisons In-flight straylight / ghosts are qualitatively similar to the pre-flight measurements Comparable sun limb straylight level in HI-1, but lower in-flight off-pointing values Ring pattern in HI-1 preliminary analysis result Work plan for CSL Continue HI-1 and HI-2 in-field and at border of FOV analysis Straylight quantitative results to be continued and refine (additional off-pointing) Earth and SWAVES boom effect in HI-2 to be confirmed when Earth will be further Comparison of HI-2 straylight with Earth-S/C-Sun angle Ghosts and straylight to be re-evaluated when in nominal orbit with Earth far enough In-flight calibration and F-Corona removal for straylight analysis results improvement Instrument other performances analysis Compare PSF to have a model of PSF for de-convolution Characterize PSF as function of position in CCD Characterize distortion for correction March 2007 SECCHI Consortium Meeting - Paris

SECCHI Consortium Meeting - Paris Back-up slides March 2007 SECCHI Consortium Meeting - Paris

Pre-flight: HI-1A straylight (0-arcdeg) Beam (B0) 2.1x10-10 B/B0 2x10-9 - 5x10-10 B/B0 7.1x10-11 B/B0 March 2007 SECCHI Consortium Meeting - Paris

Pre-flight: HI-2A straylight (0-arcdeg) Beam (B0) 2x10-10 B/B0 4x10-11 - 2x10-12 B/B0 March 2007 SECCHI Consortium Meeting - Paris