exposure-qa-EXPID.fits¶
- Summary:
These files contain the per-exposure QA measurements. Those are propagated when making coadd reductions, and helps to decide during operations if the observation is valid or not.
- Naming Convention:
exposure-qa-{expid}, where{expid}is the 8-digit exposure ID.- Regex:
exposure-qa-[0-9]{8}\.fits- File Type:
FITS, 441 KB
Contents¶
Number |
EXTNAME |
Type |
Contents |
|---|---|---|---|
IMAGE |
Keywords only |
||
FIBERQA |
BINTABLE |
Per-fiber information table |
|
PETALQA |
BINTABLE |
Per-petal information table |
FITS Header Units¶
HDU0¶
No data, checksum/datasum header keywords only.
Required Header Keywords¶
Required Header Keywords Table
KEY |
Example Value |
Type |
Comment |
|---|---|---|---|
CHECKSUM |
C4gFE4Z9C4fCC4Z9 |
str |
HDU checksum updated 2021-07-16T14:31:54 |
DATASUM |
0 |
str |
data unit checksum updated 2021-07-16T14:31:54 |
Empty HDU.
HDU1¶
EXTNAME = FIBERQA
This table contains the per-fiber information which helps to decide if the observation is valid or not. That information is also used to define some column content of the PETALQA extension.
Required Header Keywords¶
Required Header Keywords Table
KEY |
Example Value |
Type |
Comment |
|---|---|---|---|
NAXIS1 |
86 |
int |
length of dimension 1 |
NAXIS2 |
5000 |
int |
length of dimension 2 |
NIGHT |
20210514 |
int |
Exposure night |
EXPID |
88364 |
int |
Exposure ID |
NGOODFIB |
4611 |
int |
Number of fibers with EFFTIME_SPEC above the threshold |
NGOODPET |
10 |
int |
Number of petals with good fibers |
WORSTRDN |
5.072375888924774 |
float |
Worst read noise for all amplifiers of all cameras |
FPRMS2D |
0.01157238915902728 |
float |
[mm] RMS of the positioners accuracy (measured-requested) in the CS5 location of the focal plane |
PMINEXPF [1] |
0.8370916420971888 |
float |
Deprecated |
PMAXEXPF [1] |
1.27911264193688 |
float |
Deprecated |
EFFTIME |
217.9705047607422 |
float |
[s] Spectroscopic effective time |
TILEID |
21181 |
int |
Tile ID |
EXPTIME |
589.277 |
float |
[s] Tile exposure time |
MJD-OBS |
59349.20075297 |
float |
[d] Modified Julian Date of observation |
TARGTRA |
199.993521 |
float |
[deg] Target right ascension (to TCS) |
TARGTDEC |
32.447031 |
float |
[deg] Target declination (to TCS) |
MOUNTEL |
84.320435 |
float |
[deg] Mount elevation angle |
MOUNTHA |
-6.689017 |
float |
[deg] Mount hour angle |
AIRMASS |
1.004188 |
float |
Airmass |
ETCTEFF [1] |
1015.311096 |
float |
[s] Effective time computed (on-the-fly) by the ETC |
TILERA |
199.992 |
float |
[deg] Tile center Right Ascension |
TILEDEC |
32.447 |
float |
[deg] Tile center Declination |
GOALTIME [1] |
180.0 |
float |
[s] Aimed EFFTIME_SPEC |
GOALTYPE [1] |
BRIGHT |
str |
Sky conditions used for some noise estimation |
FAPRGRM [1] |
bright |
str |
Program to which this tile belongs |
SURVEY [1] |
main |
str |
Survey of origin of the targets |
EBVFAC [1] |
1.02512649227135 |
float |
10.0 ** (2.165 * median(EBV) / 2.5)) |
MINTFRAC [1] |
0.85 |
float |
Fraction of GOALTIME to be reached by EFFTIME_SPEC to consider the tile has completed |
CHECKSUM |
YP2AYM16YM1AYM13 |
str |
HDU checksum updated 2021-07-16T14:31:54 |
DATASUM |
2084006317 |
str |
data unit checksum updated 2021-07-16T14:31:54 |
Required Data Table Columns¶
Name |
Type |
Units |
Description |
|---|---|---|---|
TARGETID |
int64 |
Unique target ID |
|
PETAL_LOC |
int16 |
Petal location [0-9] |
|
DEVICE_LOC |
int32 |
Device location on focal plane [0-523] |
|
LOCATION |
int64 |
Location on the focal plane PETAL_LOC*1000 + DEVICE_LOC |
|
FIBER |
int32 |
Fiber ID on the CCDs [0-4999] |
|
TARGET_RA |
float64 |
deg |
Target Right Ascension |
TARGET_DEC |
float64 |
deg |
Target Declination |
FIBER_X |
float64 |
mm |
Fiber CS5 X location on focal plane |
FIBER_Y |
float64 |
mm |
Fiber CS5 Y location on focal plane |
DELTA_X |
float64 |
mm |
Fiber difference between measured and requested CS5 X location on focal plane |
DELTA_Y |
float64 |
mm |
Fiber difference between measured and requested CS5 Y location on focal plane |
EBV |
float32 |
mag |
Galactic extinction E(B-V) reddening |
QAFIBERSTATUS |
int32 |
Fiber status bitmask, inflated with further QA diagnoses |
|
EFFTIME_SPEC |
float32 |
s |
Spectroscopic effective time, based on template-based squared signal-to-noise ratio |
HDU2¶
EXTNAME = PETALQA
This table contains some per-petal QA information which helps to decide if the observation is valid or not, and if a petal should be considered as “bad” (i.e. as if it would not have been observed), because of a too-low quality.
Required Header Keywords¶
Required Header Keywords Table
KEY |
Example Value |
Type |
Comment |
|---|---|---|---|
NAXIS1 |
62 |
int |
length of dimension 1 |
NAXIS2 |
10 |
int |
length of dimension 2 |
CHECKSUM |
8aaf9WRc8aXc8WXc |
str |
HDU checksum updated 2021-07-16T14:31:54 |
DATASUM |
666368269 |
str |
data unit checksum updated 2021-07-16T14:31:54 |
Required Data Table Columns¶
Name |
Type |
Units |
Description |
|---|---|---|---|
PETAL_LOC |
int16 |
Petal location [0-9] |
|
WORSTREADNOISE |
float32 |
Worst read noise (each individual value being the worst across amplifiers) |
|
NGOODPOS |
int16 |
Number of valid positioners |
|
NGOODFIB |
int16 |
Number of good fibers |
|
NSTDSTAR |
int16 |
Number of standard stars used by the spectroscopic pipeline for calibration |
|
STARRMS |
float32 |
RMS of the r-band flux ratio of standard stars |
|
TSNR2FRA [1] |
float32 |
Deprecated |
|
EFFTIME_SPEC |
float32 |
s |
Median of the EFFTIME_SPEC values for all good fibers from that petal |
NCFRAME |
int16 |
Number of cframe files for that petal |
|
BSKYTHRURMS |
float32 |
Sky throuput RMS for the b-camera |
|
BSKYCHI2PDF |
float32 |
Reduced chi2 for the sky fibers for the b-camera |
|
RSKYTHRURMS |
float32 |
Sky throuput RMS for the r-camera |
|
RSKYCHI2PDF |
float32 |
Reduced chi2 for the sky fibers for the r-camera |
|
ZSKYTHRURMS |
float32 |
Sky throuput RMS for the z-camera |
|
ZSKYCHI2PDF |
float32 |
Reduced chi2 for the sky fibers for the z-camera |
|
BTHRUFRAC |
float32 |
Relative (single petal vs. all petals) throughput for the b-camera |
|
RTHRUFRAC |
float32 |
Relative (single petal vs. all petals) throughput for the r-camera |
|
ZTHRUFRAC |
float32 |
Relative (single petal vs. all petals) throughput for the z-camera |
Notes and Examples¶
These
exposure-qa-{expid}files are used to compute several of the tile-qa-TILEID-GROUPID entries.The QAFIBERSTATUS bitmasks are defined here bitmasks.
Some FIBERQA extension header keywords are originally coming from the fiberassign-TILEID file (TILEID, TILERA, TILEDEC, GOALTIME, GOALTYPE, FAPRGRM, SURVEY, EBVFAC, MINTFRAC).
The FIBERQA EFFTIME_SPEC is proportional to the TSNR2 values in the TSNR2 extension of the redrock-SPECTROGRAPH-TILEID-GROUPID file; for the BACKUP and BRIGHT programs, the TSNR2_BGS is used; for the DARK program, the TSNR2_ELG or TSNR2_LRG is used.
For the SURVEY=cmx m33 tile (TILEID=80615) tile and all the SURVEY=sv1 tiles (except TILEID=80971-80976, the dc3r2 ones), proper-motion correction was applied at the fiberassign design step; thus the following columns can have different values than in the desitarget products:
TARGET_RA,TARGET_DEC,REF_EPOCH,PLATE_RA,PLATE_DEC, andPLATE_REF_EPOCH.