A high-accuracy GNSS receiver can be used with any project with no prior configuration. Use the following workflow to use a high-accuracy receiver with ArcGIS QuickCapture:
- Choose a receiver.
- Configure your receiver.
- Connect your receiver to your device.
- Configure QuickCapture to use the receiver.
Choose a receiver
can use the GPS that's built into a device, or you can add an external GPS receiver to obtain high-accuracy data. There are many GPS receivers available; however, not all of them work directly with . To use a GPS receiver with , the receiver must support the output of sentences.
Tip:
Most high-accuracy GPS receivers support the NMEA sentences that uses; however, it's recommended that you check whether the receiver supports these NMEA sentences in the receiver's user manual before you try to connect it to .
NMEA support
NMEA 0183 is the data specification standard that uses to communicate with GPS receivers. NMEA messages contain lines of data called sentences. derives GPS information such as latitude, longitude, height, and fix type by reading specific sentences in NMEA messages.
supports NMEA 4.00 and 4.10. It can read the following NMEA sentences:
- GGA: Time, position, and fix-related data
- GSA: GNSS DOP and active satellites
- GSV: GNSS satellites in view
- RMC: Recommended minimum specific GNSS data
- VTG: Course over ground and ground speed
- GST: GNSS pseudorange error statistics
If receives GST sentences that 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.
Estimated accuracy
If doesn't receive a GST sentence from a GPS receiver but does receive a GSA sentence, 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.
Differential corrections
To improve the accuracy of positions, consider using a GPS receiver that supports differential corrections. Differential correction technology further improves accuracy by using reference stations, which are also known as base stations. A reference station is another GPS receiver that is established on a known location. The reference station estimates its location based on satellite signals and compares this estimated position to the known position. The difference between these positions is applied to the estimated GPS position calculated by the GPS receiver, also called the rover, to get a more accurate position. The receiver must be located within a certain distance of the reference station for differential corrections to occur. Differential corrections can be applied in real time in the field or when postprocessing data in the office.
Differential corrections can be provided by public or commercial sources. One of the most widely used and publicly accessible real-time correction sources is the Satellite-based Augmentation System (SBAS), which is also commonly referred to as the Wide Area Augmentation System (WAAS) in the United States. It is free to use SBAS, but the GPS receiver must support it. Using commercial correction services typically requires a subscription and may also require purchasing a particular type of GPS receiver that can receive these correction signals. For more information, see Differential GPS Explained.
GPS receivers supported on iOS
To directly connect a Bluetooth receiver with an iOS device, the receiver must be part of the MFi Program as well as support the output of NMEA sentences. The following receivers can be used directly with on supported iOS devices.
Tip:
To determine the version of firmware a GPS receiver uses, pair the receiver with a device, open the device's General > About settings, and tap the name of the paired receiver.
- Bad Elf Flex,
Bad Elf GNSS Surveyor, GPS Pro+, GPS Pro, and GPS for Lightning Connector
GNSS Surveyor and GPS Pro+ require firmware version 2.1.40 or later. GPS Pro requires firmware version 2.0.90 or later. GPS for Lightning Connector requires firmware version 1.0.24 or later.
- Eos Arrow Lite, Arrow 100, Arrow 200, and Arrow Gold—Firmware version 2.0.251 or later.
- Garmin GLO and GLO 2
GLO requires firmware version 3.00 or later and GLO 2 requires firmware version 2.1 or later.
Accuracy values delivered by the Garmin GLO do not update at the same rate as location information. Accuracy on this receiver is calculated from PDOP and HDOP values and these are outputted only once on start-up of the receiver.
- Geneq SxBlue II and SxBlue III—Firmware version 2.0.251 or later.
- Juniper Systems Geode
- Leica Zeno GG04 plus—Processor board firmware version 1.0.20 or later.
Configure a receiver
Not all receivers that support the output of NMEA sentences are configured to do so out of the box. Refer to the device's user manual for instructions on how to configure it to output NMEA sentences.
Connect a receiver to a device
supports receivers integrated into devices as well as external receivers connected via Bluetooth. If the receiver is integrated into the device, proceed to the next section. If you are using an external receiver, follow these steps to connect it to a device:
- Verify that the GPS receiver is compatible with .
The receiver must support the output of NMEA sentences and be configured to do so. See and . These instructions must be completed before connecting the receiver to .
- Turn on the receiver and place it near a device or computer.
Go to the Bluetooth settings and view the available devices. Wait for the receiver's name to appear in the list.
Tip:
If the Bluetooth receiver doesn't appear in the list, ensure that it isn't connected to another device.
- To disconnect a receiver from an iOS device, in the device's Bluetooth settings, tap the information button next to the receiver, tap Forget This Device, and tap Forget Device.
- To disconnect a receiver from an Android device, in the device's Bluetooth settings, tap the settings button next to the receiver, and tap Unpair or Forget.
- To disconnect a receiver from a Windows device, in the device's Bluetooth settings, tap the receiver's name, tap Remove device, and tap Yes.
- Tap the receiver's name to pair it with the device.
Configure QuickCapture to use the receiver
You can configure more than one receiver to use with QuickCapture. You can customize the name, alerts, antenna height, and altitude options for each receiver. These settings are saved on your device for subsequent use.
- Open QuickCapture.
- On the main menu, select Settings.
- On the settings menu, select Location Provider.
- Select Add Provider.
- From the list of external receivers, select the receiver to which you want to connect.
- The default location provider type is External receiver of type Bluetooth. The External receivers list displays all receivers that are connected to your device but are not yet added to QuickCapture. On desktop devices, you can also browse USB-connected devices. To change the type of devices that are listed, disable device discovery, check or uncheck the type of external receivers to search, and reenable discovery.
- You can also connect to receivers that are available on a network. Select Network connection, enter the host name and port, and select Add.
- If you have a NMEA log file on your device, you can connect to this to playback the recorded NMEA messages. Choose Add from File, select the log file. Choose Add.
Once a receiver is selected, it connects, and the Settings page appears. You can check or modify the receivers settings here, or select the back arrow to return to the Location page, where you can browse other configured providers, add a new provider, or close the QuickCapture settings.