CALBLOCK-PV-005: Survey Validation¶
Observation configuration file¶
Scheduling¶
Once. Early during PV phase.
In case of failure, repeat as soon as possible.
Time-critical¶
Yes. Must be observed early on during the PV phase, to see that the spacecraft and the ground segment perform as expected, and that there are no issues with the deep fields.
Dependencies¶
CALBLOCK-F-001: Self Calibration
CALBLOCK-F-007: VIS Nonlinearity, PTC, BFE and NISP LED flats
Objective¶
During PV phase, it must be ensured early on that Euclid performs as expected, that the deep field locations are without problems, and that survey-like, substantial amounts of data can be processed on ground. To this end, Euclid must observe (1) a field with well-known source properties to 5 times the S/N of the wide survey, and (2) perform a single pass of the EDF-N and - if visible - the EDF-S. The latter has limited visibility and may not be observable during PV phase. The observations must be executed as soon as essential in-flight calibration products such as flat fields and Self-cal data have become available, to provide enough lead time in case adjustments are required to the survey and / or the ground segment.
The single, deep pointing should be done of an area with extensive ground-based and space-spaced 3rd-party data, the latter providing high resolution imaging, spectroscopy, and redshifts. In this way it can be verified that (1) Euclid reaches the required sensitivity to successfully perform its principal experiments, (2) the calibrated data and catalogs match the expectation, and (3) the ground segment is capable of properly processing and stacking deep data (which can also be done with self-cal data. The depth is required to recognize systematics that would remain undetected in typical, shallower wide-survey data.
The wide observations of the EDF-N - and possibly EDF-S - provide data for about 40 square degrees, representative for typical wide-survey operations. The test verifies that (1) the spacecraft and instruments operate as expected over a longer period of time with the ROS, (2) the ground segment is capable to process such large data sets, and (3) that there are no problematic issues with these particularly important positions on sky (which will be visited frequently).
Observations¶
A single pass of the EDF-N (and EDF-S, if possible)
Multiple passes of an area with well-known source fluxes, redshifts, and ideally HST imaging, to a S/N 5 times that of the wide survey area. Observations of one of the JWST PEARLS fields, HST Frontier Fields, color gradient calibration fields or photo-z training fields are ideal because high-quality, multiwavelength data exist for them.
VIS Cycling: The VIS ROS-inline calibrations follow the nominal wide-survey cycling, as described in ROS: inline VIS calibrations and cadences.
Fulfilling¶
Targets and pointing constraints¶
Pointing: Straylight suppression as per MOCDA-SYS-003.
EDF-N and EDF-S (if visible) for the wide-survey validation, and one of the deep fields listed below with ideally 5 times the SNR, time permitting.
# ID |
R.A. |
Dec |
Type |
Visibility |
EDF-N |
270.000 |
+66.00 |
wide |
perennial |
EDF-S |
61.230 |
-48.42 |
wide |
2023-07-20 => 2023-09-25 2023-12-03 => 2023-02-05 |
EDF-F |
52.930 |
-28.09 |
wide |
2023-07-28 => 2023-09-01 |
PEARLS-NEP-TDF |
260.700 |
65.823 |
deep |
perennial; apart from 2023-09-29 to 2023-10-02 |
MACSJ0717 |
109.392 |
37.747 |
deep |
2023-10-05 => 2023-10-29 |
MACSJ0416 |
64.037 |
-24.075 |
deep |
2023-08-13 => 2023-09-16 |
Abell 370 |
39.970 |
-1.579 |
deep |
2023-07-26 => 2023-08-20 |
CANDELS/COSMOS |
150.120 |
+02.35 |
deep |
2023-11-20 => 2023-12-13 |
CANDELS/GOODS-CDFS |
53.125 |
-27.80 |
deep |
2023-07-29 => 2023-09-01 |
CANDELS/GOODS-NORTH |
189.250 |
+62.25 |
deep |
2023-11-14 => 2023-12-28 |
VVDS-Deep |
36.500 |
-04.50 |
deep |
2023-07-21 => 2023-08-16 |
CDFS |
53.117 |
-27.80 |
deep |
2023-07-29 => 2023-09-01 |
SXDS |
34.500 |
-05.00 |
deep |
2023-07-19 => 2023-08-13 |
EGS |
215.000 |
+52.90 |
deep |
2023-12-14 => 2024-02-01 |
Instrument configuration¶
Instrument: Wide survey
Methodology / Uplink procedure¶
Entity: NISP, VIS
Commanding Method: NISP: Observation, VIS: Science
Dither Sequence: ROS
Inter-operability constraints¶
None
In-orbit duration¶
In-orbit Duration: 81.3 h (EDF-N and one single-pointing deep field)
51.4 h for a single pass of the EDF-N, and 29.9 h for the single pointing deep field, assuming 43 and 25 executions of the ROS.
In addition, if visible: 64.5 h for the EDF-S.
Data volume¶
338708 MB (without EDF-S)
25*ROS = 124525 MB for the single, deep field
43*ROS = 214183 MB for the single pass of the EDF-N
54*ROS = 268974 MB for the single pass of the EDF-S (if visible)
Processing input¶
Ground Processing Input Data: All baseline calibration products, can be from ground
Data Description: 25, 43, 54, times the ROS, for the single-pointing deep field, EDF-N and EDF-S, respectively. The EDF-S may not be visible.
Processing method¶
Standard SGS processing. Offline comparison of field depth, redshifts.
Processing output¶
Most importantly, the limiting \(5\sigma\) magnitudes of the photometric exposures for point and extended sources, e.g. derived from number count histograms. Comparison with pre-launch expectations.
Likewise, line sensitivity of the NISP-S spectra.
Comparison of NISP-S redshifts, and Euclid photo-zs with known spectroscopic redshifts in the field.
Standard pipeline output products (catalogs)
Required accuracy, constraints¶
Successful flux and redshift measurements of sources
Processing tools¶
L1 pipelines
Validation¶
Determine the depth, number counts, and relative photometric accuracy of the exposures. This can be used to validates the top-level requirements in the MRD and CalCD-A directly.
The achieved image quality (PSF size and ellipticity) must be within expectations. A detailed weak lensing PSF study is not needed as this point, because it requires the output of CALBLOCK-PV-008: Phase Diversity Calibration.
Recovery¶
A performance below the CalCD-A requirements is mission-critical. The root cause must be investigated and a mitigation strategy implemented, such as improved calibrations, adjusted NISP MACC modes, and / or change in survey design.
Quality control parameters¶
DataModel: https://gitlab.euclid-sgs.uk/
Contact person¶
Calibration lead, Survey Scientist