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Record GPS metadata

Besides geographic coordinates, you might also want to save other GPS metadata associated with a feature, such as its accuracy and fix type. Storing this metadata can be valuable to assess data quality and ensure data collection standards have been maintained. You can add GPS metadata fields to a point feature service so Collector can write GPS metadata to the respective fields when editing point features. You should also configure the feature pop-up to hide some of the data from your data collectors.

Here are a few things to keep in mind before configuring GPS metadata storage:

  • GPS metadata fields are populated on point layers only.
  • If a point feature is created or updated by long pressing the map instead of using GPS, the GPS metadata fields are cleared.
  • If a point feature is created or updated and GPS metadata information is not available for the GPS position, the GPS metadata fields are cleared.

Supported GPS metadata

The following GPS metadata values are recorded by Collector when using a configured feature service:

  • Receiver name
  • Latitude—Location before applying the specified location profile, including data transformations
  • Longitude—Location before applying the specified location profile, including data transformations
  • Altitude—Location before applying the specified location profile, including data transformations
  • Fix time

If using a single GPS location to set a point's location, the following metadata values are also recorded:

  • Horizontal accuracy
  • Vertical accuracy
  • PDOP
  • HDOP
  • VDOP
  • Fix type
  • Correction age
  • Station ID
  • Number of satellites

If performing GPS averaging to set a point's location, the following metadata values are also recorded:

  • Average horizontal accuracy
  • Average vertical accuracy
  • Number of positions averaged
  • Standard deviation

    An indication of the variation in distance between your final, averaged location and each individual location recorded during averaging. A high value indicates your position was influenced by outliers.

You can choose which of these you capture with your data: the values are ignored for any fields you don't add to your feature service. Similarly, you can set up your data for single GPS locations, averaged locations, or both: when averaging is enabled, the associated fields are populated and those for single location collection are left blank, and vice versa.

Note:

If you enabled a 95 percent confidence level for accuracy in the Collector settings, a 95 percent confidence level is used to determine if your accuracy is acceptable for data collection. The recorded accuracies are still calculated using root mean square (RMS). As such, the level of confidence in the recorded accuracies is 63 percent to 68 percent for horizontal accuracy and 68 percent for vertical accuracy.

Configure a feature service to store GPS metadata

To configure your feature service for GPS metadata storage, you can either use Python scripts or make the changes manually:

  • If you use ArcGIS Desktop to publish the service, you can add the GPS metadata fields to the feature attribute tables prior to publishing the service by using the Python scripts or by manually updating your data.
  • If you use ArcGIS Online or ArcGIS Enterprise to create and update your layers, you can't use Python scripts to add the GPS metadata fields to the feature attribute table. You need to make the change manually. See Manually update your data for details.

Manually update your data

To manually configure your feature service for GPS metadata storage, follow the steps below.

Caution:

Before you begin, evaluate whether you can use Python scripts instead. You should only follow these steps if you are using ArcGIS Online or ArcGIS Enterprise to create and update your layers.

  1. If you want to use domains for the Fix Type, Number of Satellites, and Station ID fields you'll create in the next step, first use the details below to create the GNSSFixType, NumSatellites, and NumStationID domains in your database. Using domains to populate these three fields is optional. For more information, see An overview of attribute domains in the ArcGIS Pro help.

    Note:

    Hosted feature layers created in ArcGIS Online or ArcGIS Enterprise do not support adding domains.

    • Domain 1: Coded value domain
      • Name: GNSSFixType
      • Field type: Short integer
      • Values: 0—Fix not valid, 1—GPS, 2—Differential GPS, 4—RTK Fixed, 5—RTK Float
    • Domain 2: Range domain
      • Name: NumSatellites
      • Field type: Short integer
      • Range: 0–99
    • Domain 3: Range domain
      • Name: NumStationID
      • Field type: Short integer
      • Range: 0–1023
  2. Determine what GPS metadata you need to capture as you do your data collection. For each piece of metadata you need to capture, add the corresponding field from the following table to the feature attribute table of the service.
    Note:

    Any fields you do not add will be ignored.

    AttributeField aliasField nameField typeDomain

    Receiver name

    Receiver Name

    ESRIGNSS_RECEIVER

    String(50)

    Horizontal accuracy

    Horizontal Accuracy (m)

    ESRIGNSS_H_RMS

    double

    Vertical accuracy

    Vertical Accuracy (m)

    ESRIGNSS_V_RMS

    double

    Latitude

    Latitude

    ESRIGNSS_LATITUDE

    double

    Longitude

    Longitude

    ESRIGNSS_LONGITUDE

    double

    Altitude

    Altitude

    ESRIGNSS_ALTITUDE

    double

    PDOP

    PDOP

    ESRIGNSS_PDOP

    double

    HDOP

    HDOP

    ESRIGNSS_HDOP

    double

    VDOP

    VDOP

    ESRIGNSS_VDOP

    double

    Fix type

    Fix Type

    ESRIGNSS_FIXTYPE

    Short

    GNSSFixType (optional)

    Correction age

    Correction Age

    ESRIGNSS_CORRECTIONAGE

    double

    Station ID

    Station ID

    ESRIGNSS_STATIONID

    Short

    NumStationID (optional)

    Number of satellites

    Number of Satellites

    ESRIGNSS_NUMSATS

    Short

    NumSatellites (optional)

    Fix time

    Fix Time

    ESRIGNSS_FIXDATETIME

    Date

    Average horizontal accuracy

    Average Horizontal Accuracy (m)

    ESRIGNSS_AVG_H_RMS

    double

    Average vertical accuracy

    Average Vertical Accuracy (m)

    ESRIGNSS_AVG_V_RMS

    double

    Number of positions averaged

    Averaged Positions

    ESRIGNSS_AVG_POSITIONS

    Long

    Standard deviation

    Standard Deviation (m)

    ESRIGNSS_H_STDDEV

    double

Configure GPS metadata fields in the feature layer pop-up

After configuring metadata storage, it's recommended that you configure the feature layer pop-up to hide or make read-only certain GPS metadata fields from mobile workers in order to prevent these fields from being edited. You can either use Python scripts or manually update your pop-up. To use the scripts to configure a feature layer's pop-up, you need to configure it in the map as opposed to in the layer.

Tip:

If you are configuring your pop-up in the map, use Python scripts. If you are configuring it on the layer, manually update your pop-up.

Manually update your pop-up

To manually configure your pop-up on the layer to hide the associated fields, follow the steps below. See Configure the data collection form for details about editing pop-ups.

Caution:

Before you begin, evaluate whether you can use Python scripts instead. You should only follow these steps if you are configuring your pop-up on the layer instead of on the map.

  1. While editing your pop-up, click Configure Attributes.
  2. Uncheck Edit for each of the fields you added to capture GPS metadata in the last section. This prevents data collectors from editing the values.
  3. If you want to make certain GPS metadata fields read-only, so that mobile workers can verify that they have met data collection accuracy requirements, check Display for those fields. For fields you are displaying, it is recommended that you format the field based on the following table:

    Field nameField aliasField format

    ESRIGNSS_RECEIVER

    Receiver Name

    N/A

    ESRIGNSS_H_RMS

    Horizontal Accuracy (m)

    2 decimal places

    ESRIGNSS_V_RMS

    Vertical Accuracy (m)

    2 decimal places

    ESRIGNSS_LATITUDE

    Latitude

    8 decimal places

    ESRIGNSS_LONGITUDE

    Longitude

    8 decimal places

    ESRIGNSS_ALTITUDE

    Altitude

    2 decimal places

    ESRIGNSS_PDOP

    PDOP

    2 decimal places

    ESRIGNSS_HDOP

    HDOP

    2 decimal places

    ESRIGNSS_VDOP

    VDOP

    2 decimal places

    ESRIGNSS_FIXTYPE

    Fix Type

    N/A

    ESRIGNSS_CORRECTIONAGE

    Correction Age (seconds)

    0 decimal places

    ESRIGNSS_STATIONID

    Station ID

    N/A

    ESRIGNSS_NUMSATS

    Number of Satellites

    N/A

    ESRIGNSS_FIXDATETIME

    Fix Time

    ShortDateTime, 12hr

    ESRIGNSS_AVG_H_RMS

    Average Horizontal Accuracy (m)

    2 decimal places

    ESRIGNSS_AVG_V_RMS

    Average Vertical Accuracy (m)

    2 decimal places

    ESRIGNSS_AVG_POSITIONS

    Averaged Positions

    N/A

    ESRIGNSS_H_STDDEV

    Standard Deviation (m)

    3 decimal places

  4. If there are fields you don't want data collectors to see, uncheck Display for those fields.