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  1. Request For Comments
  2. RFC-271

Standardized schema for proper motions in reference catalogs

    Details

    • Type: RFC
    • Status: Implemented
    • Resolution: Done
    • Component/s: DM
    • Labels:
      None
    • Location:
      This RFC

      Description

      We will need to apply proper motion corrections (when available) to our reference catalogs when generating astrometric solutions. We have no current standardized schema for these columns. Following suggestions from Paul Price following the lead of Pan-STARRS, I propose the following column names and units.

      pmRa -- Proper motion in the RA coordinate (mas/yr; float32)
      pmRaErr -- Error in proper motion in the RA coordinate (mas/yr; float32)
      pmDec -- Proper motion in the Declination coordinate (mas/yr; float32)
      pmDecErr -- Error in proper motion in the Declination coordinate (mas/yr; float32)
      epoch -- Mean epoch (TAI MJD for which the position needs no proper motion correction; float64)
      

      Note that the definitions above allow direct application of the proper motion correction by multiplying pmRa and pmDec by the difference in epoch in units of years. If the angular distance travelled is to be calculated a correction term to pmRa of cos(Dec) is required (or one could do the dot product in Cartesian 3-space).

      If pmRaErr or pmDecErr are missing, zero error will be assumed. If any of pmRa, pmDec, or epoch are missing, no proper motion correction will be applied.

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            krughoff Simon Krughoff created issue -
            krughoff Simon Krughoff made changes -
            Field Original Value New Value
            Link This issue is triggering DM-8837 [ DM-8837 ]
            price Paul Price made changes -
            Description We will need to apply proper motion corrections (when available) to our reference catalogs when generating astrometric solutions. We have no current standardized schema for these columns. Following suggestions from [~price] following the lead of Pan-STARRS, I propose the following column names and units.
            {noformat}
            pm_ra -- Proper motion in the RA coordinate (arcsec/yr)
            pm_ra_err -- Error in proper motion in the RA coordinate (arcsec/yr)
            pm_dec -- Proper motion in the Declination coordinate (arcsec/yr)
            pm_dec_err -- Error in proper motion in the Declination coordinate (arcsec/yr)
            epoch -- Mean epoch (seconds relative to the UNIX epoch)
            {noformat}

            Note that the definitions above allow direct application of the proper motion correction by multiplying {{pm_ra}} and {{pm_dec}} by the difference in epoch in units of years. If the angular distance travelled is to be calculated a correction term to {{pm_ra}} of {{cos(Dec)}} is required (or one could do the dot product in Cartesian 3-space).

            If {{pm_ra_err}} or {{pm_dec_err}} are missing, zero error will be assumed. If any of {{pm_ra}}, {{pm_dec}}, or {{epoch}} are missing, no proper motion correction will be applied.
            We will need to apply proper motion corrections (when available) to our reference catalogs when generating astrometric solutions. We have no current standardized schema for these columns. Following suggestions from [~price] following the lead of Pan-STARRS, I propose the following column names and units.
            {noformat}
            pm_ra -- Proper motion in the RA coordinate (arcsec/yr; float32)
            pm_ra_err -- Error in proper motion in the RA coordinate (arcsec/yr; float32)
            pm_dec -- Proper motion in the Declination coordinate (arcsec/yr; float32)
            pm_dec_err -- Error in proper motion in the Declination coordinate (arcsec/yr; float32)
            epoch -- Mean epoch (seconds relative to the UNIX epoch; int64)
            {noformat}

            Note that the definitions above allow direct application of the proper motion correction by multiplying {{pm_ra}} and {{pm_dec}} by the difference in epoch in units of years. If the angular distance travelled is to be calculated a correction term to {{pm_ra}} of {{cos(Dec)}} is required (or one could do the dot product in Cartesian 3-space).

            If {{pm_ra_err}} or {{pm_dec_err}} are missing, zero error will be assumed. If any of {{pm_ra}}, {{pm_dec}}, or {{epoch}} are missing, no proper motion correction will be applied.
            krughoff Simon Krughoff made changes -
            Description We will need to apply proper motion corrections (when available) to our reference catalogs when generating astrometric solutions. We have no current standardized schema for these columns. Following suggestions from [~price] following the lead of Pan-STARRS, I propose the following column names and units.
            {noformat}
            pm_ra -- Proper motion in the RA coordinate (arcsec/yr; float32)
            pm_ra_err -- Error in proper motion in the RA coordinate (arcsec/yr; float32)
            pm_dec -- Proper motion in the Declination coordinate (arcsec/yr; float32)
            pm_dec_err -- Error in proper motion in the Declination coordinate (arcsec/yr; float32)
            epoch -- Mean epoch (seconds relative to the UNIX epoch; int64)
            {noformat}

            Note that the definitions above allow direct application of the proper motion correction by multiplying {{pm_ra}} and {{pm_dec}} by the difference in epoch in units of years. If the angular distance travelled is to be calculated a correction term to {{pm_ra}} of {{cos(Dec)}} is required (or one could do the dot product in Cartesian 3-space).

            If {{pm_ra_err}} or {{pm_dec_err}} are missing, zero error will be assumed. If any of {{pm_ra}}, {{pm_dec}}, or {{epoch}} are missing, no proper motion correction will be applied.
            We will need to apply proper motion corrections (when available) to our reference catalogs when generating astrometric solutions. We have no current standardized schema for these columns. Following suggestions from [~price] following the lead of Pan-STARRS, I propose the following column names and units.
            {noformat}
            pm_ra -- Proper motion in the RA coordinate (mas/yr; float32)
            pm_ra_err -- Error in proper motion in the RA coordinate (mas/yr; float32)
            pm_dec -- Proper motion in the Declination coordinate (mas/yr; float32)
            pm_dec_err -- Error in proper motion in the Declination coordinate (mas/yr; float32)
            epoch -- Mean epoch (MJD (TAI) for which the position needs no proper motion correction; float32)
            {noformat}

            Note that the definitions above allow direct application of the proper motion correction by multiplying {{pm_ra}} and {{pm_dec}} by the difference in epoch in units of years. If the angular distance travelled is to be calculated a correction term to {{pm_ra}} of {{cos(Dec)}} is required (or one could do the dot product in Cartesian 3-space).

            If {{pm_ra_err}} or {{pm_dec_err}} are missing, zero error will be assumed. If any of {{pm_ra}}, {{pm_dec}}, or {{epoch}} are missing, no proper motion correction will be applied.
            krughoff Simon Krughoff made changes -
            Description We will need to apply proper motion corrections (when available) to our reference catalogs when generating astrometric solutions. We have no current standardized schema for these columns. Following suggestions from [~price] following the lead of Pan-STARRS, I propose the following column names and units.
            {noformat}
            pm_ra -- Proper motion in the RA coordinate (mas/yr; float32)
            pm_ra_err -- Error in proper motion in the RA coordinate (mas/yr; float32)
            pm_dec -- Proper motion in the Declination coordinate (mas/yr; float32)
            pm_dec_err -- Error in proper motion in the Declination coordinate (mas/yr; float32)
            epoch -- Mean epoch (MJD (TAI) for which the position needs no proper motion correction; float32)
            {noformat}

            Note that the definitions above allow direct application of the proper motion correction by multiplying {{pm_ra}} and {{pm_dec}} by the difference in epoch in units of years. If the angular distance travelled is to be calculated a correction term to {{pm_ra}} of {{cos(Dec)}} is required (or one could do the dot product in Cartesian 3-space).

            If {{pm_ra_err}} or {{pm_dec_err}} are missing, zero error will be assumed. If any of {{pm_ra}}, {{pm_dec}}, or {{epoch}} are missing, no proper motion correction will be applied.
            We will need to apply proper motion corrections (when available) to our reference catalogs when generating astrometric solutions. We have no current standardized schema for these columns. Following suggestions from [~price] following the lead of Pan-STARRS, I propose the following column names and units.
            {noformat}
            pm_ra -- Proper motion in the RA coordinate (mas/yr; float32)
            pm_ra_err -- Error in proper motion in the RA coordinate (mas/yr; float32)
            pm_dec -- Proper motion in the Declination coordinate (mas/yr; float32)
            pm_dec_err -- Error in proper motion in the Declination coordinate (mas/yr; float32)
            epoch -- Mean epoch (MJD (TAI) for which the position needs no proper motion correction; float64)
            {noformat}

            Note that the definitions above allow direct application of the proper motion correction by multiplying {{pm_ra}} and {{pm_dec}} by the difference in epoch in units of years. If the angular distance travelled is to be calculated a correction term to {{pm_ra}} of {{cos(Dec)}} is required (or one could do the dot product in Cartesian 3-space).

            If {{pm_ra_err}} or {{pm_dec_err}} are missing, zero error will be assumed. If any of {{pm_ra}}, {{pm_dec}}, or {{epoch}} are missing, no proper motion correction will be applied.
            krughoff Simon Krughoff made changes -
            Description We will need to apply proper motion corrections (when available) to our reference catalogs when generating astrometric solutions. We have no current standardized schema for these columns. Following suggestions from [~price] following the lead of Pan-STARRS, I propose the following column names and units.
            {noformat}
            pm_ra -- Proper motion in the RA coordinate (mas/yr; float32)
            pm_ra_err -- Error in proper motion in the RA coordinate (mas/yr; float32)
            pm_dec -- Proper motion in the Declination coordinate (mas/yr; float32)
            pm_dec_err -- Error in proper motion in the Declination coordinate (mas/yr; float32)
            epoch -- Mean epoch (MJD (TAI) for which the position needs no proper motion correction; float64)
            {noformat}

            Note that the definitions above allow direct application of the proper motion correction by multiplying {{pm_ra}} and {{pm_dec}} by the difference in epoch in units of years. If the angular distance travelled is to be calculated a correction term to {{pm_ra}} of {{cos(Dec)}} is required (or one could do the dot product in Cartesian 3-space).

            If {{pm_ra_err}} or {{pm_dec_err}} are missing, zero error will be assumed. If any of {{pm_ra}}, {{pm_dec}}, or {{epoch}} are missing, no proper motion correction will be applied.
            We will need to apply proper motion corrections (when available) to our reference catalogs when generating astrometric solutions. We have no current standardized schema for these columns. Following suggestions from [~price] following the lead of Pan-STARRS, I propose the following column names and units.
            {noformat}
            pm_ra -- Proper motion in the RA coordinate (mas/yr; float32)
            pm_ra_err -- Error in proper motion in the RA coordinate (mas/yr; float32)
            pm_dec -- Proper motion in the Declination coordinate (mas/yr; float32)
            pm_dec_err -- Error in proper motion in the Declination coordinate (mas/yr; float32)
            epoch -- Mean epoch (TAI MJD for which the position needs no proper motion correction; float64)
            {noformat}

            Note that the definitions above allow direct application of the proper motion correction by multiplying {{pm_ra}} and {{pm_dec}} by the difference in epoch in units of years. If the angular distance travelled is to be calculated a correction term to {{pm_ra}} of {{cos(Dec)}} is required (or one could do the dot product in Cartesian 3-space).

            If {{pm_ra_err}} or {{pm_dec_err}} are missing, zero error will be assumed. If any of {{pm_ra}}, {{pm_dec}}, or {{epoch}} are missing, no proper motion correction will be applied.
            krughoff Simon Krughoff made changes -
            Resolution Done [ 10000 ]
            Status Proposed [ 10805 ] Adopted [ 10806 ]
            Parejkoj John Parejko made changes -
            Link This issue relates to DM-8828 [ DM-8828 ]
            krughoff Simon Krughoff made changes -
            Description We will need to apply proper motion corrections (when available) to our reference catalogs when generating astrometric solutions. We have no current standardized schema for these columns. Following suggestions from [~price] following the lead of Pan-STARRS, I propose the following column names and units.
            {noformat}
            pm_ra -- Proper motion in the RA coordinate (mas/yr; float32)
            pm_ra_err -- Error in proper motion in the RA coordinate (mas/yr; float32)
            pm_dec -- Proper motion in the Declination coordinate (mas/yr; float32)
            pm_dec_err -- Error in proper motion in the Declination coordinate (mas/yr; float32)
            epoch -- Mean epoch (TAI MJD for which the position needs no proper motion correction; float64)
            {noformat}

            Note that the definitions above allow direct application of the proper motion correction by multiplying {{pm_ra}} and {{pm_dec}} by the difference in epoch in units of years. If the angular distance travelled is to be calculated a correction term to {{pm_ra}} of {{cos(Dec)}} is required (or one could do the dot product in Cartesian 3-space).

            If {{pm_ra_err}} or {{pm_dec_err}} are missing, zero error will be assumed. If any of {{pm_ra}}, {{pm_dec}}, or {{epoch}} are missing, no proper motion correction will be applied.
            We will need to apply proper motion corrections (when available) to our reference catalogs when generating astrometric solutions. We have no current standardized schema for these columns. Following suggestions from [~price] following the lead of Pan-STARRS, I propose the following column names and units.
            {noformat}
            pmRa -- Proper motion in the RA coordinate (mas/yr; float32)
            pmRaErr -- Error in proper motion in the RA coordinate (mas/yr; float32)
            pmDec -- Proper motion in the Declination coordinate (mas/yr; float32)
            pmDecErr -- Error in proper motion in the Declination coordinate (mas/yr; float32)
            epoch -- Mean epoch (TAI MJD for which the position needs no proper motion correction; float64)
            {noformat}

            Note that the definitions above allow direct application of the proper motion correction by multiplying {{pmRa}} and {{pmDec}} by the difference in epoch in units of years. If the angular distance travelled is to be calculated a correction term to {{pmRa}} of {{cos(Dec)}} is required (or one could do the dot product in Cartesian 3-space).

            If {{pmRaErr}} or {{pmDecErr}} are missing, zero error will be assumed. If any of {{pmRa}}, {{pmDec}}, or {{epoch}} are missing, no proper motion correction will be applied.
            jbosch Jim Bosch made changes -
            Resolution Done [ 10000 ]
            Status Adopted [ 10806 ] Flagged [ 10606 ]
            jbosch Jim Bosch made changes -
            Risk Score 0
            jbosch Jim Bosch made changes -
            Status Flagged [ 10606 ] Proposed [ 10805 ]
            rowen Russell Owen made changes -
            Comment [ Another question: what about covariance (correlation) for position and/or proper motion? Gaia provides a number of these, including RA/Dec and mixtures of that with proper motion. SDSS does not. ]
            rowen Russell Owen made changes -
            Watchers Jim Bosch, John Parejko, Kian-Tat Lim, Paul Price, Russell Owen, Simon Krughoff, Tim Jenness [ Jim Bosch, John Parejko, Kian-Tat Lim, Paul Price, Russell Owen, Simon Krughoff, Tim Jenness ] Jim Bosch, John Parejko, Kian-Tat Lim, Paul Price, Robert Lupton, Russell Owen, Simon Krughoff, Tim Jenness [ Jim Bosch, John Parejko, Kian-Tat Lim, Paul Price, Robert Lupton, Russell Owen, Simon Krughoff, Tim Jenness ]
            jbosch Jim Bosch made changes -
            Planned End 09/Jan/17 6:00 PM 20/Jul/18 11:00 PM
            rowen Russell Owen made changes -
            Risk Score 0 1
            jbosch Jim Bosch made changes -
            Link This issue relates to DM-15174 [ DM-15174 ]
            jbosch Jim Bosch made changes -
            Assignee Simon Krughoff [ krughoff ] Russell Owen [ rowen ]
            rowen Russell Owen made changes -
            Risk Score 1 0
            rowen Russell Owen made changes -
            Link This issue relates to RFC-502 [ RFC-502 ]
            rowen Russell Owen made changes -
            Link This issue relates to RFC-333 [ RFC-333 ]
            rowen Russell Owen made changes -
            Status Proposed [ 10805 ] Adopted [ 10806 ]
            rowen Russell Owen made changes -
            Resolution Done [ 10000 ]
            Status Adopted [ 10806 ] Implemented [ 11105 ]

              People

              • Assignee:
                rowen Russell Owen
                Reporter:
                krughoff Simon Krughoff
                Watchers:
                Christopher Waters, Colin Slater, Jim Bosch, John Parejko, Kian-Tat Lim, Paul Price, Robert Lupton, Russell Owen, Simon Krughoff, Tim Jenness
              • Votes:
                1 Vote for this issue
                Watchers:
                10 Start watching this issue

                Dates

                • Created:
                  Updated:
                  Resolved:
                  Planned End:

                  Summary Panel