CHEOPS SIMULATED DATA SET EXAMPLES ********************************** README, aka "Which files contain what?" 1. High level products containing the information most relevant for data analysis ================================================================================= - Data Reduction Visit Report CH_PR*_RPT_COR_DataReduction_V0000.pdf. 
This report provides an illustrated summary of the data reduction steps applied by the pipeline - Light curve extracted for several aperture sizes CH_PR*_SCI_COR_Lightcurve-{DEFAULT,OPTIMAL,RINF,RSUP}_V0000.fits
These files also contain flags/events, estimates for background and contaminants, roll angle and target centroid position (at the cadence of stacked images, if applicable). The aperture information is provided in the DR Visit Report and as keywords AP_RADI and AP_TYPE in the FITS file. - Event flags The 'EVENT' column in the SCI_COR_Lightcurve data structures should be decoded according to the position of decimal digits in the flag: |7|6|5|4|3|2|1|0| - pos. 0: SAA (0: outside; 1: inside) we can also define 2: border of SAA (need definition) - pos. 1: Temperature (0: within range; 1: outside range (soft); 2: outside range (hard); - pos. 2: EARTH (0: above threshold; 1: below threshold (soft=35 degrees); 2: below threshold (hard=25 degrees); 9: earth occultation) - pos. 3: MOON (0: above threshold; 1: below threshold (soft=5 degrees); 2: below threshold (hard=5 degrees);) - pos. 4: SUN (0: above threshold; 1: below threshold (soft=120 degrees); 2: below threshold (hard=120 degrees);) - pos. 5: CR pixel (0: below threshold; 1: >1% aperture CR contaminated; 2: >5% frame CR contaminated )
For example: The event 901 means: 9=earth occultation & 0=Temp OK & 1 =inside SAA (the rest of the digits to the left of the 9 are 0 = OK) - Corrected subarray data cube CH_PR*_SCI_COR_SubArray_V0000.fits
This file contains the fully corrected stacked images, the metadata (WCS, angles between LOS and Sun/Earth/Moon), the target centroid position, and the smearing information. From these files the DRP extracts the light curves to CH_PR*_SCI_COR_Lightcurve-*_V0000.fits. - CHEOPS reduced light curves are in FITS files called 
CH_PR*_SCI_COR_Lightcurve-*_V0000.fits. 2. Mid-level products, possibly useful for deeper analysis ========================================================== - Target centroid position at cadence of individual exposures: CH_PR*_SCI_RAW_Centroid_V0100.fits - Spacecraft attitude (RA, Dec, roll) at cadence of AOCS data: CH_PR*_SCI_RAW_Attitude_V0100.fits - Imagettes data cube at cadence of individual exposures, or at cadence of stacked imagettes if applicable: CH_PR*_SCI_RAW_Imagette_V0100.fits - Star catalogue of Gaia field stars: CH_PR*_EXT_PRE_StarCatalogue-OBSID*_V0000.fits - Raw FullFrame array with side/top margins and metadata: CH_PR*_SCI_RAW_FullArray_V0100.fits - Information based on the restituted/measured orbit (angles, latitude/longitude, Earth occultation and SAA flags): CH_PR*_AUX_RES_VisitConstraints_V0100.fits - Quick Look reports (one per pass): CH_PR*_RPT_RAW_QuickLook_V0100.pdf - Calibrated subarray data cube: CH_PR*_SCI_CAL_SubArray_V0000.fits 3. Low level products, mostly relevant to the SOC and the Instrument Team ========================================================================= - log files: CH_*.log - Raw subarray data cube: CH_PR*_SCI_RAW_SubArray_V0100.fits - Raw products per pass: CH_PR*_TG*_PS*.fits - Pre-processing visit report: CH_PR*_RPT_RAW_Visit_V0100.pdf - House Keepings: CH_PR*_SCI_RAW_Hk*_V0100.fits - Event report: CH_PR*_SCI_RAW_EventReport_V0100.fits - Visit combination summary: CH_PR*_PIP_REP_Text-visit_combination_V0100.fits 4. Differences with real data ============================= While these simulated data sets are largely identical to expected real data from CHEOPS, a number of differences exist. They are listed below for the sake of completion but are not foreseen to impact most possible usage of these simulated data sets. 1. Roll angle is not (yet) provided in CH_PR*_SCI_COR_Lightcurve-*_V0000.fits. Instead, the Roll angle may be retrieved at cadence of individual exposures from CH_PR*_SCI_RAW_Attitude_V0100.fits. 2. Target centroid position is provided in CH_PR*_SCI_COR_Lightcurve-OPTIMAL_V0000.fits but in the wrong column (Location_X/Y instead of Centroid_X/Y) 3. Target centroid position is currently provided relative to the bottom left corner of the window frame. It will in the future be relative to the bottom left corner of the CCD full frame. The pixel coordinates of the bottom left corner of the window frame relative to the bottom left corner of the CCD is provided in the header of the first extension of SCI_COR_SubArray as X/Y_WINOFF. 4. Smearing information is empty in CH_PR*_SCI_COR_SubArray_V0000.fits. 5. The event flagging by the data reduction pipeline is still based on the angles to SUN/MOON/EARTH from the AUX_RES_VisitsConstraints, which is sampled at a 5-minute cadence. With this coarse cadence, some frames may be flagged inappropriately. For Straylight event flagging (EARTH=1 or 2), the data reduction pipeline uses angles between line-of-sight and Earth to set the flags instead of using the predicted straylight levels and applicable thresholds. Some frames may be flagged inappropriately.