tile-qa-TILEID-GROUPID.fits¶
- Summary:
These files are mostly associated with
cumulativetile coadds. They contain information which helps to decide during operations if the observation is valid or not.- Naming Convention:
tile-qa-TILEID-GROUPID.fits, whereTILEIDis the tile number andGROUPIDdepends on theGROUPTYPEof the tile coadd.- Regex:
tile-qa-[0-9]+-(thru[0-9]{8}|[0-9]{8})\.fits- File Type:
FITS, 627 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 |
D5aEE4a9D4aED4a9 |
str |
HDU checksum updated 2021-07-16T19:03:01 |
DATASUM |
0 |
str |
data unit checksum updated 2021-07-16T19:03:01 |
Empty HDU.
HDU1¶
EXTNAME = FIBERQA
This table contains the per-fiber information which helps to decide if the observation is valid or not. For each fiber, the QA information is computed from the QA information for that fiber in all exposures used for that tile coadd reduction (see exposure-qa-EXPID). 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 |
124 |
int |
length of dimension 1 |
NAXIS2 |
5000 |
int |
length of dimension 2 |
TILEID |
20096 |
int |
Tile ID |
LASTNITE |
20210608 |
int |
Last night of data included in this coadd reduction |
NGOODFIB |
3992 |
int |
Number of fibers with EFFTIME_SPEC above the threshold |
NGOODPET |
9 |
int |
Number of petals with good fibers (only used for plotting routines) |
EFFTIME |
214.8598327636719 |
float |
[s] Median of EFFTIME_SPEC of fibers that are good in all exposures |
VALID |
T |
bool |
A tile is valid if EFFTIME > MINTFRAC*GOALTIME AND NGOODFIB > threshold |
RMSDIST |
0.01416921149939299 |
float |
[mm] RMS distance of good fibers |
TILERA |
229.546 |
float |
[deg] Tile Right Ascension |
TILEDEC |
-0.056 |
float |
[deg] Tile Declination |
GOALTIME |
180.0 |
float |
[s] Aimed EFFTIME_SPEC |
GOALTYPE |
BRIGHT |
str |
Sky conditions used for some noise estimation |
FAPRGRM |
bright |
str |
Program to which this tile belongs |
SURVEY |
main |
str |
Survey of origin of the targets |
EBVFAC |
1.12631027332157 |
float |
10.0 ** (2.165 * median(EBV) / 2.5)) |
MINTFRAC |
0.85 |
float |
Fraction of GOALTIME to be reached by EFFTIME_SPEC to consider the tile has completed |
CHECKSUM |
73CQ71BN71BN71BN |
str |
HDU checksum updated 2021-07-16T19:03:01 |
DATASUM |
105714500 |
str |
data unit checksum updated 2021-07-16T19:03:01 |
Required Data Table Columns¶
Name |
Type |
Units |
Description |
|---|---|---|---|
TARGETID |
int64 |
Unique DESI 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 |
MEAN_FIBER_X |
float32 |
mm |
Mean (over exposures) fiber CS5 X location on focal plane |
MEAN_FIBER_Y |
float32 |
mm |
Mean (over exposures) fiber CS5 Y location on focal plane |
MEAN_DELTA_X |
float32 |
mm |
Mean (over exposures) fiber difference requested - actual CS5 X location on focal plane |
MEAN_DELTA_Y |
float32 |
mm |
Mean (over exposures) fiber difference requested - actual CS5 Y location on focal plane |
RMS_DELTA_X |
float32 |
mm |
RMS (over exposures) of the fiber difference between measured and requested CS5 X location on focal plane |
RMS_DELTA_Y |
float32 |
mm |
RMS (over exposures) of the fiber difference between measured and requested CS5 Y location on focal plane |
DESI_TARGET |
int64 |
DESI (dark time program) target selection bitmask |
|
BGS_TARGET |
int64 |
BGS (Bright Galaxy Survey) target selection bitmask |
|
EBV |
float32 |
mag |
Galactic extinction E(B-V) reddening from SFD98 |
TSNR2_LRG |
float64 |
LRG template (S/N)^2 summed over B,R,Z |
|
Z |
float64 |
Redshift measured by Redrock |
|
SPECTYPE |
char[6] |
Spectral type of Redrock best fit template (e.g. GALAXY, QSO, STAR) |
|
DELTACHI2 |
float64 |
chi2 difference between first- and second-best redrock template fits |
|
QAFIBERSTATUS |
int32 |
Fiber status bitmask, inflated with further QA diagnoses |
|
EFFTIME_SPEC |
float32 |
s |
Effective exposure time for nominal conditions derived from the TSNR2 fits to the spectroscopy |
HDU2¶
EXTNAME = PETALQA
This table contains the per-petal 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. It is the mean (over exposures) of the PETALQA extension of the exposure-qa-EXPID values, to which we refer for the column definition.
Required Header Keywords¶
Required Header Keywords Table
KEY |
Example Value |
Type |
Comment |
|---|---|---|---|
NAXIS1 |
66 |
int |
length of dimension 1 |
NAXIS2 |
10 |
int |
length of dimension 2 |
CHECKSUM |
5m3P8l1M5l1M5l1M |
str |
HDU checksum updated 2021-07-16T19:03:01 |
DATASUM |
807618843 |
str |
data unit checksum updated 2021-07-16T19:03:01 |
Required Data Table Columns¶
Name |
Type |
Units |
Description |
|---|---|---|---|
PETAL_LOC |
int16 |
Petal location [0-9] |
|
WORSTREADNOISE |
float32 |
Mean of the per-exposure WORSREADNOISE |
|
NGOODPOS |
float32 |
Mean of the per-exposure NGOODPOS |
|
NSTDSTAR |
float32 |
Mean of the per-exposure NSTDSTAR |
|
STARRMS |
float32 |
Mean of the per-exposure STARRMS |
|
TSNR2FRA [1] |
float32 |
Deprecated column |
|
NCFRAME |
float32 |
Mean of the per-exposure NCFRAME |
|
BSKYTHRURMS |
float32 |
Mean of the per-exposure BSKYTHRURMS |
|
BSKYCHI2PDF |
float32 |
Mean of the per-exposure BSKYCHI2PDF |
|
RSKYTHRURMS |
float32 |
Mean of the per-exposure RSKYTHRURMS |
|
RSKYCHI2PDF |
float32 |
Mean of the per-exposure RSKYCHI2PDF |
|
ZSKYTHRURMS |
float32 |
Mean of the per-exposure ZSKYTHRURMS |
|
ZSKYCHI2PDF |
float32 |
Mean of the per-exposure ZSKYCHI2PDF |
|
BTHRUFRAC |
float32 |
Mean of the per-exposure BTHRUFRAC |
|
RTHRUFRAC |
float32 |
Mean of the per-exposure RTHRUFRAC |
|
ZTHRUFRAC |
float32 |
Mean of the per-exposure ZTHRUFRAC |
|
EFFTIME_SPEC |
float32 |
s |
Median effective exposure time for nominal conditions derived from the TSNR2 fits to the spectroscopy |
Notes and Examples¶
For some data releases, this
tile-qa-TILEID-GROUPID.fitsalso exists for the tile per-night coadd reductions.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.