1 / 16

EIS Calibration and Operation

EIS Calibration and Operation. H. Hara NAOJ. Calibration on the ground. Component-level calibration - Multi-layer mirror reflectance - Multi-layer grating efficiency - Filter transmissions - CCD camera calibration - FMIR position accuracy for raster scan

havily
Download Presentation

EIS Calibration and Operation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. EIS Calibration and Operation H. Hara NAOJ

  2. Calibration on the ground • Component-level calibration - Multi-layer mirror reflectance - Multi-layer grating efficiency - Filter transmissions - CCD camera calibration - FMIR position accuracy for raster scan - CMIR mechanism position accuracy for FOV setting • Instrument-level calibration - Effective area calibration: preliminary one is in SSW - Wavelength calibration - Instrumental width in emission lines short band: 47mA long band: 58mA - Primary mirror focus check - Grating focus check Published in Seely et al. 2004, App. Opt., 43, No7,1463

  3. On-Orbit Calibration • On-Orbit calibration - Cross-check of effective area by using density insensitive line ratio - Wavelength calibration in an orbit - Estimation of contamination and degradation - Estimation of absorption by Earth’s atmosphere in low-altitude sun-synchronous orbit - Check of MDP compression (DPCM/JPEG) performance using the actual solar spectra/images. - Calibration rocket flight planned (EUNIS) by NASA GSFC group

  4. EIS Science Operation (SO) • Team core science • Initial science targets • Proposal from users Preparation for EIS SO Merging EIS SO in S/C operation - Obs. table - S/C CMDs EIS Planning EGSE Observation Planning Science ISACS-PLN Feedback Plan approved for EIS operation Feedback Final S/C plan Line selection Exp. duration Compression FOV size etc. Data rate Compression Instrument CAL Check of Obs. Table using PM Outcome Uplink station Analysis Data check Data for analysis Level0 data Level1 data Level2 data Spacecraft Data Reformat EGSE Users Observation in orbit Telemetry Downlink stations JAXA data storage Data centers

  5. Summary • Deep understanding of the Calibration Issues and Science Operation leads to good science. For easy analysis knowledge of calibration will be installed in EIS analysis software. • Various observations can be performed with the EIS Sequence structure (EIS observation table).

  6. END

  7. Al III, Al IV and Ne IV lines EIS Calibration Spectrum 2" slit • Calibration is being carried out with the source used for SOHO CDS calibration (Hollandt et al., 2002, Lang et al., 2000) • Source is a secondary standard radiometrically calibrated by PTB, Berlin at the BESSY I electron storage ring • Stable high-current hollow-cathode discharge lamp provides appropriate EUV emission lines • Following EIS calibration, the source will be re-calibrated at BESSY II

  8. EIS Effective Area

  9. EIS Science Targets Bright Point Limb/beyond the limb Active region/Flares Quiet Sun/ Network brightening Coronal Hole Coronal Hole Boundary Polar Plume

  10. Data Rate CCD1 CCD0 CCD readout height Software window (SW) EIS data size to MDP = total sum of software windows =  (window width)i * (window height)i Assemble all SWs DPCM MDP EIS data of CCSDS format JPEG Compression ratio = compressed data size/ input data size to MDP Data rate ~ [EIS data size to MDP] * [Compression Ratio] / Cadence

  11. EIS Data Flow Data compression DPCM(loss less) or 12bit-JPEG Small spectral window (25 max) CCD Readout Electronics 2Mbps max 1.3 Mbps EIS ICU S/C MDP control  260 kbps max for short duration, 45 kbps average Large hardware CCD window Observation table 1 slit obs. 40 slot obs. 250 slot obs. Spec.width 16 40 250 Spatial width 256 512 256 No. of lines 8 4 4 Compression* 25% 20 % 20% Cadence 3 sec 6 sec 20 sec Rate 42.7 kbps 42.7 kbps 40 kbps Average rate depends on number of downlink station. Telemetry data format *for 16 bit/pixel data 13 min cadence for 44 rastering

  12. EIS Observation Sequence On-board S/C commands Change SEQ Start Stop Change SEQ Start Change SEQ Start Stop Stop OBS5 OBS1 OBS4 OBS2 OBS3 Stop Start Upload new plan Uplink commands Data rate Time

  13. EIS Observations An example of 240" 240" FOV Discontinuous raster 240 " 240 " 1" slit raster 2" slit raster Wider instrumental width EUV imaging of less contamination by other lines 40" slit raster 266" slit raster (no mirror motion) Contribution of other emission lines

  14. MDP JPEG Compression AR spectrum for 5 sec integration Fe XII 256 pixels Fe XII Fe XV Fe XI Fe XII Fe XII Fe XIII Fe XXIV Ca XVII Fe XIII Fe XIV Fe XVI 224 pixels He II Fe XIV

  15. JPEG compression error X: signal – offset [DN] ; offset~ 500 Y: decomp( comp( Original ) ) – Original [DN] DN17nm DN29nm

  16. Compression Error for Q=85 Compression ratio = 0.19 v FWHM I original original original Diff/ FWHM Diff/ I Diff/ v = = =

More Related