AUTHORS : A. Martel and G. Hartig
The goal of this campaign is to obtain a potentially final set of all calibration data for the HRC Build 1 and WFC Build 4 flight detectors with RAS/HOMS (Refractive Aberrated Simulator/Hubble Opto-Mechanical Simulator), which provides an external, OTA-like illumination above its refractive cutoff wavelength of ~3500 Ang. A host of activities will be undertaken to acquire pre-launch data that would be prohibitive or impossible to obtain on-orbit or at GSFC. The SBC has been fully calibrated in the first thermal vacuum campaign (TV1) and so is not considered in this campaign.
LOCATION AND DATE : BATC : Feb 20 - Mar 2, 2001
INSTRUMENT CONFIGURATION :
ACS is fully integrated and all flight detectors are in final alignment in RAS/HOMS in ambient environment. The lab chillers are attached to the ASCS I/F plate. It is assumed that at the start of the calibration program, the instrument is in its flight configuration and has been fully verified. No adjustments, alignments, or other modifications to hardware or software are expected once this program commences. If such changes are made, some aspects of the calibration may be rendered invalid. The clean room is light-tight. By default, all the data will be acquired with MEB 1, although if time permits, comparison data will also be obtained with MEB 2. The default gain settings are 1 e-/DN for the WFC and 2 e-/DN for the HRC, with a bias offset of 3 for both detectors. The WFC will be read-out with all four amplifiers (ABCD) and the HRC with amp C, the least noisy of its four amps. A brief description of the chip formats is available.
The different light stimuli and optical elements used in RAS/HOMS for this campaign are described in detail in Calibration Facilities, Test Apparatuses, and Stimuli.
CALIBRATION ACTIVITIES :
The calibration activities for this campaign are divided into several items, listed in the following table. The estimated execution time for each activity is tabulated, as well as the command mode, either in real time (RT) or by SMS.
|1. Image Qual. vs Field Pos.||HeNe||Normal||15||RT/SMS||9 field pos. for WFC
1 field pos. for HRC
|2. Aperture Location and Scale||HeNe||Normal||0||RT/SMS||Same data as Item 1.|
|3. Ext. "White Light" FF||150 W Lamp||Diffuser (PP)||45||RT/SMS||Complete flat-field program.|
|4. Ext. Monochr. FF||QTH+Monochr.||Diffuser (PP)||26||RT/SMS||Fringe flats and ramp filter evaluation.|
|5. Wheel Pos. vs Ramp Wavelength||QTH+Monochr.||Diffuser (PP)||20||RT||Get 5 wavelengths/segment/aperture.|
|6. Grism Dispersion||Hg, Ar Line Lamps||Pinhole Array + Lens||2||RT||Cover 5800-11000 Ang with G800L.|
|7. Straylight Evaluation (Point Source)||HeNe||Normal||14||RT||Scan edges and gap (WFC) with PSF fibers.|
|8. Straylight Evaluation (Field)||HeNe||Inv. Field Masks +
|8||RT||Use 3 mask sizes and adjacent centration with all fibers.|
|9. Geometric Distortions||QTH||Ronchi+Diffuser (FP)||4||RT||Two sets with Ronchi ruling offset by 90 deg..|
|10. Shutter Performance||QTH||Diffuser (FP)||10||SMS||Shading, linearity, and accuracy.|
|11. Coronagraph Performance||HeNe||Normal||8||RT||Scan Fastie finger and both spots with one PSF/fiber.|
|12. Gain Measurements||T2, T4||Internal||12||SMS||Measure the primary gain settings (1,2,4), onset of non-linearity, and saturation.|