Merge pull request #177 from desihub/radec_warnings

Radec warnings
desihub · Jun 8, 2023 · 1833e84 · 1833e84
2 parents ec332b6 + 4c3c7c9
commit 1833e84
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diff --git a/doc/DESI_ROOT/survey/fiberassign/SURVEY/TILEXX/TILEID-scnd.rst b/doc/DESI_ROOT/survey/fiberassign/SURVEY/TILEXX/TILEID-scnd.rst
@@ -103,3 +103,9 @@ PLATE_RA              float64  deg       Barycentric Right Ascension in ICRS to
 PLATE_DEC             float64  deg       Barycentric Declination in ICRS to be used by PlateMaker
 PLATE_REF_EPOCH       float32  yr        Copy of REF_EPOCH to be used by PlateMaker
 ===================== ======== ========= =======================================================================================================
+
+
+Notes and Examples
+==================
+
+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 :doc:`fiberassign </DESI_TARGET/fiberassign/tiles/TILES_VERSION/TILEXX/fiberassign-TILEID>` design step; thus the following columns can have different values than in the :doc:`desitarget products </DESI_TARGET/TARG_DIR/DR/VERSION/targets/PHASE/RESOLVE/OBSCON/PHASEtargets-OBSCON-RESOLVE-hp-HP>`: ``TARGET_RA``, ``TARGET_DEC``, ``REF_EPOCH``, ``PLATE_RA``, ``PLATE_DEC``, and ``PLATE_REF_EPOCH``.
diff --git a/doc/DESI_ROOT/survey/fiberassign/SURVEY/TILEXX/TILEID-targ.rst b/doc/DESI_ROOT/survey/fiberassign/SURVEY/TILEXX/TILEID-targ.rst
@@ -134,6 +134,8 @@ PLATE_REF_EPOCH       float32  yr           Copy of REF_EPOCH to be used by Plat
 Notes and Examples
 ==================
 
+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 :doc:`fiberassign </DESI_TARGET/fiberassign/tiles/TILES_VERSION/TILEXX/fiberassign-TILEID>` design step; thus the following columns can have different values than in the :doc:`desitarget products </DESI_TARGET/TARG_DIR/DR/VERSION/targets/PHASE/RESOLVE/OBSCON/PHASEtargets-OBSCON-RESOLVE-hp-HP>`: ``TARGET_RA``, ``TARGET_DEC``, ``REF_EPOCH``, ``PLATE_RA``, ``PLATE_DEC``, and ``PLATE_REF_EPOCH``.
+
 Some units in this file do not conform to the FITS standard:
 
 * nanomaggy^-2 is incorrectly recorded as 1/nanomaggy^2

diff --git a/doc/DESI_ROOT/survey/fiberassign/SURVEY/TILEXX/TILEID-too.rst b/doc/DESI_ROOT/survey/fiberassign/SURVEY/TILEXX/TILEID-too.rst
@@ -104,6 +104,8 @@ PLATE_REF_EPOCH               float64  yr        Copy of REF_EPOCH to be used by
 Notes and Examples
 ==================
 
+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 :doc:`fiberassign </DESI_TARGET/fiberassign/tiles/TILES_VERSION/TILEXX/fiberassign-TILEID>` design step; thus the following columns can have different values than in the :doc:`desitarget products </DESI_TARGET/TARG_DIR/DR/VERSION/targets/PHASE/RESOLVE/OBSCON/PHASEtargets-OBSCON-RESOLVE-hp-HP>`: ``TARGET_RA``, ``TARGET_DEC``, ``REF_EPOCH``, ``PLATE_RA``, ``PLATE_DEC``, and ``PLATE_REF_EPOCH``.
+
 Some units in this file do not conform to the FITS standard:
 
 * d is incorrectly recorded as day

diff --git a/doc/DESI_ROOT/vac/RELEASE/lss/VERSION/inputs_wspec/data/datcomb_tarspecwdup.rst b/doc/DESI_ROOT/vac/RELEASE/lss/VERSION/inputs_wspec/data/datcomb_tarspecwdup.rst
@@ -60,21 +60,21 @@ Name                       Type        Units     Description
 ========================== =========== ========= ===============================================================================================================================
 RA                         float64     deg       Target Right Ascension
 DEC                        float64     deg       Target declination
-REF_EPOCH                  float32     yr        Reference epoch for Gaia/Tycho astrometry. Typically 2015.5 for Gaia
-PARALLAX                   float32     mas       Reference catalog parallax
-PMRA                       float32     mas yr^-1 proper motion in the +RA direction (already including cos(dec))
-PMDEC                      float32     mas yr^-1 Proper motion in the +Dec direction
+REF_EPOCH [1]_             float32     yr        Reference epoch for Gaia/Tycho astrometry. Typically 2015.5 for Gaia
+PARALLAX [1]_              float32     mas       Reference catalog parallax
+PMRA [1]_                  float32     mas yr^-1 proper motion in the +RA direction (already including cos(dec))
+PMDEC [1]_                 float32     mas yr^-1 Proper motion in the +Dec direction
 TARGETID                   int64                 Unique DESI target ID
-OBSCONDITIONS              int32                 Bitmask of allowed observing conditions
+OBSCONDITIONS [1]_         int32                 Bitmask of allowed observing conditions
 PRIORITY_INIT              int64                 Target initial priority from target selection bitmasks and OBSCONDITIONS
-NUMOBS_INIT                int64                 Initial number of observations for target calculated across target selection bitmasks and OBSCONDITIONS
-NUMOBS_MORE                int64                 Number of additional observations needed
-NUMOBS                     int64                 Number of spectroscopic observations (on this specific, single tile)
+NUMOBS_INIT [1]_           int64                 Initial number of observations for target calculated across target selection bitmasks and OBSCONDITIONS
+NUMOBS_MORE [1]_           int64                 Number of additional observations needed
+NUMOBS [1]_                int64                 Number of spectroscopic observations (on this specific, single tile)
 ZWARN_MTL                  int64                 The ZWARN from the zmtl file (contains extra bits)
-ZTILEID                    int32                 ID of tile that most recently updated target&#x27;s state
+ZTILEID [1]_               int32                 ID of tile that most recently updated target&#x27;s state
 TARGET_STATE               char[30]              Combination of target class and its current observational state
 TIMESTAMP                  char[25]    s         UTC/ISO time at which the target state was updated
-VERSION                    char[14]              Tag of desitarget used to create the target catalog
+VERSION [1]_               char[14]              Tag of desitarget used to create the target catalog
 PRIORITY                   int64                 Target current priority
 LOCATION                   int64                 Location on the focal plane PETAL_LOC*1000 + DEVICE_LOC
 TILEID                     int64                 Unique DESI tile ID
@@ -126,4 +126,4 @@ SV3_BGS_TARGET             int64                 BGS (bright time program) targe
 SV3_MWS_TARGET             int64                 MWS (bright time program) target selection bitmask for SV3
 ========================== =========== ========= ===============================================================================================================================
 
-
+.. [1] Optional
diff --git a/doc/DESI_SPECTRO_DATA/NIGHT/EXPID/coordinates-EXPID.rst b/doc/DESI_SPECTRO_DATA/NIGHT/EXPID/coordinates-EXPID.rst
@@ -199,3 +199,9 @@ STATCOR_Y_1 float64         TODO: description needed
 STAT_X_1    float64         TODO: description needed
 STAT_Y_1    float64         TODO: description needed
 =========== ========= ===== ===================
+
+
+Notes and Examples
+==================
+
+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 :doc:`fiberassign </DESI_TARGET/fiberassign/tiles/TILES_VERSION/TILEXX/fiberassign-TILEID>` design step; thus the following columns can have different values than in the :doc:`desitarget products </DESI_TARGET/TARG_DIR/DR/VERSION/targets/PHASE/RESOLVE/OBSCON/PHASEtargets-OBSCON-RESOLVE-hp-HP>`: ``TARGET_RA``, ``TARGET_DEC``, ``REF_EPOCH``, ``PLATE_RA``, ``PLATE_DEC``, and ``PLATE_REF_EPOCH``.
diff --git a/doc/DESI_SPECTRO_DATA/NIGHT/EXPID/pm-EXPID.rst b/doc/DESI_SPECTRO_DATA/NIGHT/EXPID/pm-EXPID.rst
@@ -440,3 +440,5 @@ at high dec: the proper motions are applied after target positions have
 been converted to tangent plane coordinates centered on the field center,
 but are not corrected to account for the fact that lines of constant
 RA and DEC are not Cartesian coordinates in the tangent plane.
+
+For targets with a non-zero proper motion, ``FIBER_RA`` and ``FIBER_DEC`` refer to the position at the reference epoch (but note that the proper-motion correction has been applied at the time of the observation, it is just not recorded in ``FIBER_RA`` and ``FIBER_DEC``).
diff --git a/doc/DESI_SPECTRO_REDUX/SPECPROD/exposures/NIGHT/EXPID/cframe-CAMERA-EXPID.rst b/doc/DESI_SPECTRO_REDUX/SPECPROD/exposures/NIGHT/EXPID/cframe-CAMERA-EXPID.rst
@@ -1567,5 +1567,6 @@ while ELGs weight redder wavelengths more due to the wavelengths of the
 observed emission lines.  For more details, see section 4.14 of
 `Guy et al 2023 <https://ui.adsabs.harvard.edu/abs/2023AJ....165..144G/abstract>`_.
 
+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 :doc:`fiberassign </DESI_TARGET/fiberassign/tiles/TILES_VERSION/TILEXX/fiberassign-TILEID>` design step; thus the following columns can have different values than in the :doc:`desitarget products </DESI_TARGET/TARG_DIR/DR/VERSION/targets/PHASE/RESOLVE/OBSCON/PHASEtargets-OBSCON-RESOLVE-hp-HP>`: ``TARGET_RA``, ``TARGET_DEC``, ``REF_EPOCH``, ``PLATE_RA``, ``PLATE_DEC``, and ``PLATE_REF_EPOCH``.
 
-
+For targets with a non-zero proper motion, ``FIBER_RA`` and ``FIBER_DEC`` refer to the position at the reference epoch (but note that the proper-motion correction has been applied at the time of the observation, it is just not recorded in ``FIBER_RA`` and ``FIBER_DEC``).
diff --git a/doc/DESI_SPECTRO_REDUX/SPECPROD/exposures/NIGHT/EXPID/exposure-qa-EXPID.rst b/doc/DESI_SPECTRO_REDUX/SPECPROD/exposures/NIGHT/EXPID/exposure-qa-EXPID.rst
@@ -183,3 +183,4 @@ Notes and Examples
 * The QAFIBERSTATUS bitmasks are defined here :doc:`bitmasks <../../../../../../bitmasks>`.
 * Some FIBERQA extension header keywords are originally coming from the :doc:`fiberassign-TILEID <../../../../../DESI_TARGET/fiberassign/tiles/TILES_VERSION/TILEXX/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 :doc:`redrock-SPECTROGRAPH-TILEID-GROUPID <../../../tiles/GROUPTYPE/TILEID/GROUPID/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 :doc:`fiberassign </DESI_TARGET/fiberassign/tiles/TILES_VERSION/TILEXX/fiberassign-TILEID>` design step; thus the following columns can have different values than in the :doc:`desitarget products </DESI_TARGET/TARG_DIR/DR/VERSION/targets/PHASE/RESOLVE/OBSCON/PHASEtargets-OBSCON-RESOLVE-hp-HP>`: ``TARGET_RA``, ``TARGET_DEC``, ``REF_EPOCH``, ``PLATE_RA``, ``PLATE_DEC``, and ``PLATE_REF_EPOCH``.
diff --git a/doc/DESI_SPECTRO_REDUX/SPECPROD/exposures/NIGHT/EXPID/fluxcalib-CAMERA-EXPID.rst b/doc/DESI_SPECTRO_REDUX/SPECPROD/exposures/NIGHT/EXPID/fluxcalib-CAMERA-EXPID.rst
@@ -1454,3 +1454,7 @@ We may add an additional HDU with ``EXTNAME=METADATA`` containing a
 binary table with one row per standard star giving
 the details of which model was used, etc.
 This is not yet implemented and details TBD.
+
+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 :doc:`fiberassign </DESI_TARGET/fiberassign/tiles/TILES_VERSION/TILEXX/fiberassign-TILEID>` design step; thus the following columns can have different values than in the :doc:`desitarget products </DESI_TARGET/TARG_DIR/DR/VERSION/targets/PHASE/RESOLVE/OBSCON/PHASEtargets-OBSCON-RESOLVE-hp-HP>`: ``TARGET_RA``, ``TARGET_DEC``, ``REF_EPOCH``, ``PLATE_RA``, ``PLATE_DEC``, and ``PLATE_REF_EPOCH``.
+
+For targets with a non-zero proper motion, ``FIBER_RA`` and ``FIBER_DEC`` refer to the position at the reference epoch (but note that the proper-motion correction has been applied at the time of the observation, it is just not recorded in ``FIBER_RA`` and ``FIBER_DEC``).
diff --git a/doc/DESI_SPECTRO_REDUX/SPECPROD/exposures/NIGHT/EXPID/frame-CAMERA-EXPID.rst b/doc/DESI_SPECTRO_REDUX/SPECPROD/exposures/NIGHT/EXPID/frame-CAMERA-EXPID.rst
@@ -1480,3 +1480,11 @@ Required Header Keywords
     ======== ================ ==== ==============================================
 
 Data: FITS image [float32, 2751x500]
+
+
+Notes and Examples
+==================
+
+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 :doc:`fiberassign </DESI_TARGET/fiberassign/tiles/TILES_VERSION/TILEXX/fiberassign-TILEID>` design step; thus the following columns can have different values than in the :doc:`desitarget products </DESI_TARGET/TARG_DIR/DR/VERSION/targets/PHASE/RESOLVE/OBSCON/PHASEtargets-OBSCON-RESOLVE-hp-HP>`: ``TARGET_RA``, ``TARGET_DEC``, ``REF_EPOCH``, ``PLATE_RA``, ``PLATE_DEC``, and ``PLATE_REF_EPOCH``.
+
+For targets with a non-zero proper motion, ``FIBER_RA`` and ``FIBER_DEC`` refer to the position at the reference epoch (but note that the proper-motion correction has been applied at the time of the observation, it is just not recorded in ``FIBER_RA`` and ``FIBER_DEC``).
diff --git a/doc/DESI_SPECTRO_REDUX/SPECPROD/exposures/NIGHT/EXPID/sframe-CAMERA-EXPID.rst b/doc/DESI_SPECTRO_REDUX/SPECPROD/exposures/NIGHT/EXPID/sframe-CAMERA-EXPID.rst
@@ -1444,3 +1444,11 @@ Required Header Keywords
     ======== ================ ==== ==============================================
 
 Data: FITS image [float32, 2326x500]
+
+
+Notes and Examples
+==================
+
+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 :doc:`fiberassign </DESI_TARGET/fiberassign/tiles/TILES_VERSION/TILEXX/fiberassign-TILEID>` design step; thus the following columns can have different values than in the :doc:`desitarget products </DESI_TARGET/TARG_DIR/DR/VERSION/targets/PHASE/RESOLVE/OBSCON/PHASEtargets-OBSCON-RESOLVE-hp-HP>`: ``TARGET_RA``, ``TARGET_DEC``, ``REF_EPOCH``, ``PLATE_RA``, ``PLATE_DEC``, and ``PLATE_REF_EPOCH``.
+
+For targets with a non-zero proper motion, ``FIBER_RA`` and ``FIBER_DEC`` refer to the position at the reference epoch (but note that the proper-motion correction has been applied at the time of the observation, it is just not recorded in ``FIBER_RA`` and ``FIBER_DEC``).
diff --git a/...SI_SPECTRO_REDUX/SPECPROD/exposures/NIGHT/EXPID/stdstars-SPECTROGRAPH-EXPID.rst b/...SI_SPECTRO_REDUX/SPECPROD/exposures/NIGHT/EXPID/stdstars-SPECTROGRAPH-EXPID.rst
@@ -915,3 +915,9 @@ NIGHT  int64         Night of observation (YYYYMMDD) starting at local noon befo
 EXPID  int64         DESI Exposure ID number
 CAMERA char[2]       Camera identifier. Passband and SPECGRPH ([brz][0-9]).
 ====== ======= ===== ================================================================================
+
+
+Notes and Examples
+==================
+
+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 :doc:`fiberassign </DESI_TARGET/fiberassign/tiles/TILES_VERSION/TILEXX/fiberassign-TILEID>` design step; thus the following columns can have different values than in the :doc:`desitarget products </DESI_TARGET/TARG_DIR/DR/VERSION/targets/PHASE/RESOLVE/OBSCON/PHASEtargets-OBSCON-RESOLVE-hp-HP>`: ``TARGET_RA``, ``TARGET_DEC``, ``REF_EPOCH``, ``PLATE_RA``, ``PLATE_DEC``, and ``PLATE_REF_EPOCH``.
diff --git a/...SPECPROD/healpix/SURVEY/PROGRAM/PIXGROUP/PIXNUM/coadd-SURVEY-PROGRAM-PIXNUM.rst b/...SPECPROD/healpix/SURVEY/PROGRAM/PIXGROUP/PIXNUM/coadd-SURVEY-PROGRAM-PIXNUM.rst
@@ -760,3 +760,6 @@ The format supports arbitrary channel (camera) names as long as for each channel
 there is a set of HDUs named {X}_WAVELENGTH, {X}_FLUX, {X}_IVAR, {X}_MASK,
 {X}_RESOLUTION.
 
+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 :doc:`fiberassign </DESI_TARGET/fiberassign/tiles/TILES_VERSION/TILEXX/fiberassign-TILEID>` design step; thus the following columns can have different values than in the :doc:`desitarget products </DESI_TARGET/TARG_DIR/DR/VERSION/targets/PHASE/RESOLVE/OBSCON/PHASEtargets-OBSCON-RESOLVE-hp-HP>`: ``TARGET_RA``, ``TARGET_DEC``, ``REF_EPOCH``, ``PLATE_RA``, ``PLATE_DEC``, and ``PLATE_REF_EPOCH``.
+
+For targets with a non-zero proper motion, ``FIBER_RA`` and ``FIBER_DEC`` refer to the position at the reference epoch (but note that the proper-motion correction has been applied at the time of the observation, it is just not recorded in ``FIBER_RA`` and ``FIBER_DEC``).
diff --git a/...ECPROD/healpix/SURVEY/PROGRAM/PIXGROUP/PIXNUM/redrock-SURVEY-PROGRAM-PIXNUM.rst b/...ECPROD/healpix/SURVEY/PROGRAM/PIXGROUP/PIXNUM/redrock-SURVEY-PROGRAM-PIXNUM.rst
@@ -364,3 +364,6 @@ This file is for redshifts from an individual healpixel.
 For a contatenation of all such files within a given survey and program, see the
 :doc:`zpix file </DESI_SPECTRO_REDUX/SPECPROD/zcatalog/zpix-SURVEY-PROGRAM>`.
 
+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 :doc:`fiberassign </DESI_TARGET/fiberassign/tiles/TILES_VERSION/TILEXX/fiberassign-TILEID>` design step; thus the following columns can have different values than in the :doc:`desitarget products </DESI_TARGET/TARG_DIR/DR/VERSION/targets/PHASE/RESOLVE/OBSCON/PHASEtargets-OBSCON-RESOLVE-hp-HP>`: ``TARGET_RA``, ``TARGET_DEC``, ``REF_EPOCH``, ``PLATE_RA``, ``PLATE_DEC``, and ``PLATE_REF_EPOCH``.
+
+For targets with a non-zero proper motion, ``FIBER_RA`` and ``FIBER_DEC`` refer to the position at the reference epoch (but note that the proper-motion correction has been applied at the time of the observation, it is just not recorded in ``FIBER_RA`` and ``FIBER_DEC``).
diff --git a/...ECPROD/healpix/SURVEY/PROGRAM/PIXGROUP/PIXNUM/spectra-SURVEY-PROGRAM-PIXNUM.rst b/...ECPROD/healpix/SURVEY/PROGRAM/PIXGROUP/PIXNUM/spectra-SURVEY-PROGRAM-PIXNUM.rst
@@ -734,4 +734,6 @@ The format supports arbitrary channel names as long as for each channel {X}
 there is a set of HDUs named {X}_WAVELENGTH, {X}_FLUX, {X}_IVAR, {X}_MASK,
 {X}_RESOLUTION.
 
+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 :doc:`fiberassign </DESI_TARGET/fiberassign/tiles/TILES_VERSION/TILEXX/fiberassign-TILEID>` design step; thus the following columns can have different values than in the :doc:`desitarget products </DESI_TARGET/TARG_DIR/DR/VERSION/targets/PHASE/RESOLVE/OBSCON/PHASEtargets-OBSCON-RESOLVE-hp-HP>`: ``TARGET_RA``, ``TARGET_DEC``, ``REF_EPOCH``, ``PLATE_RA``, ``PLATE_DEC``, and ``PLATE_REF_EPOCH``.
 
+For targets with a non-zero proper motion, ``FIBER_RA`` and ``FIBER_DEC`` refer to the position at the reference epoch (but note that the proper-motion correction has been applied at the time of the observation, it is just not recorded in ``FIBER_RA`` and ``FIBER_DEC``).
diff --git a/doc/DESI_SPECTRO_REDUX/SPECPROD/preproc/NIGHT/EXPID/fibermap-EXPID.rst b/doc/DESI_SPECTRO_REDUX/SPECPROD/preproc/NIGHT/EXPID/fibermap-EXPID.rst
@@ -605,3 +605,11 @@ CMX_TARGET [1]_       int64                Target selection bitmask for commissi
 ===================== ======= ============ =========================================================================================================================
 
 .. [1] Optional
+
+
+Notes and Examples
+==================
+
+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 :doc:`fiberassign </DESI_TARGET/fiberassign/tiles/TILES_VERSION/TILEXX/fiberassign-TILEID>` design step; thus the following columns can have different values than in the :doc:`desitarget products </DESI_TARGET/TARG_DIR/DR/VERSION/targets/PHASE/RESOLVE/OBSCON/PHASEtargets-OBSCON-RESOLVE-hp-HP>`: ``TARGET_RA``, ``TARGET_DEC``, ``REF_EPOCH``, ``PLATE_RA``, ``PLATE_DEC``, and ``PLATE_REF_EPOCH``.
+
+For targets with a non-zero proper motion, ``FIBER_RA`` and ``FIBER_DEC`` refer to the position at the reference epoch (but note that the proper-motion correction has been applied at the time of the observation, it is just not recorded in ``FIBER_RA`` and ``FIBER_DEC``).
diff --git a/doc/DESI_SPECTRO_REDUX/SPECPROD/preproc/NIGHT/EXPID/preproc-CAMERA-EXPID.rst b/doc/DESI_SPECTRO_REDUX/SPECPROD/preproc/NIGHT/EXPID/preproc-CAMERA-EXPID.rst
@@ -1387,3 +1387,11 @@ SV2_MWS_TARGET [1]_   int64                      MWS (bright time program) targe
 ===================== ======= ================== =======================================================================================================================================
 
 .. [1] Optional
+
+
+Notes and Examples
+==================
+
+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 :doc:`fiberassign </DESI_TARGET/fiberassign/tiles/TILES_VERSION/TILEXX/fiberassign-TILEID>` design step; thus the following columns can have different values than in the :doc:`desitarget products </DESI_TARGET/TARG_DIR/DR/VERSION/targets/PHASE/RESOLVE/OBSCON/PHASEtargets-OBSCON-RESOLVE-hp-HP>`: ``TARGET_RA``, ``TARGET_DEC``, ``REF_EPOCH``, ``PLATE_RA``, ``PLATE_DEC``, and ``PLATE_REF_EPOCH``.
+
+For targets with a non-zero proper motion, ``FIBER_RA`` and ``FIBER_DEC`` refer to the position at the reference epoch (but note that the proper-motion correction has been applied at the time of the observation, it is just not recorded in ``FIBER_RA`` and ``FIBER_DEC``).