The following are some frequently asked questions that Collector users often have. For FAQs of data collection map authors, see FAQs for map creation.
- How do I get the app?
- Can I work with related records in Collector?
- How can I give feedback on the app?
- What is the licensing of the app?
- Can I roll back to a previous version of the app?
- Is my GPS receiver compatible with Collector?
- How does Collector determine the accuracy of GPS positions?
- What level of accuracy can I expect from an external GPS receiver?
- Using an Android device, can I save my downloaded basemaps to my SD card rather than my device's internal storage?
Yes. The following editing scenarios for related features and tables are supported:
- Feature-to-table relationships (one-to-one and one-to-many)
- Feature-to-feature relationships (one-to-one and one-to-many)
- Table-to-table relationships (when the first table is accessed through a feature)
When using related data, it is strongly recommended that you use GlobalIDs when defining relationships. User-maintained relationships are not recommended. See Supported data for details.
Collector supports internal GPS receivers and external GPS receivers that output NMEA sentences. See GPS receiver support for a list of NMEA sentences that Collector can read and a list of GPS receivers that can be used with Collector on supported iOS devices.
Collector reports accuracy based on the most accurate information available. Collector first tries to determine accuracy from NMEA sentences, which can be outputted by both internal and external receivers. Collector can read various types of NMEA sentences, including GST and GSA sentences.
If Collector receives GST sentences, which contain accuracy information for a particular coordinate, it uses them to determine accuracy. By default, the horizontal and vertical accuracy numbers are specified in root mean square (RMS). The level of confidence using RMS is 63 percent to 68 percent for horizontal accuracy, and 68 percent for vertical accuracy. If the 95% confidence accuracy setting is enabled, Collector applies a conversion factor to the RMS calculation and reports horizontal and vertical accuracy with a 95 percent confidence level.
If Collector doesn't receive a GST sentence from a GPS receiver, but does receive a GSA sentence, Collector estimates accuracy using horizontal dilution of precision (HDOP) and vertical dilution of precision (VDOP). The estimated horizontal accuracy is calculated by multiplying HDOP by 4.7, and the estimated vertical accuracy is calculated by multiplying VDOP by 4.7.
If Collector does not receive valid NMEA sentences from a receiver, it uses the accuracy reported by the device's location service.
The best way to determine the accuracy level to expect from a particular external GPS receiver is to check the website of the receiver's vendor for GPS specs. If you would like to compare accuracy levels of various external GPS receivers, you might find the MTDC GPS Receiver Horizontal Accuracy Reports and Tested Accuracies published by the USDA Forest Service helpful. This organization has been testing GPS receivers of various grades to determine their horizontal accuracy in different canopy cover conditions, and in some cases, different GPS settings. While Esri does not endorse the Forest Service's results, they may be a useful guide to determine which receiver best suits your organization's needs. Esri does not officially recommend any specific receiver for use with Collector.
Using an Android device, can I save my downloaded basemaps to my SD card rather than my device's internal storage?
Yes, you can save your downloaded basemaps to your Android device's SD card. To use the SD card, go to the Map Gallery and select Settings from the Overflow menu . Under General, set Basemap download location to SD card. By default, it is set to Internal storage.
If your device doesn't support using an SD card, you won't see the Basemap download location setting.