GPS with Collector for ArcGIS Ken Carrier: Senior GIS Specialist Craig Bruner: GIS Specialist Best Practices

GPS with Collector for ArcGIS I. Background a. Discuss the differences between Collector in the past and newer versions II. Configuring GPS with Collector a. GPS Receiver Compatibility b. Supplementary Applications c. Adding GNSS Metadata to Features III. Datum Considerations IV. Step-by-Step Process of Configuring GPS with Collector V. Live Demonstration

Background

Collector mapping applications are used broadly for various workflows, including inspections and asset management. One major issue with Collector in the past was a lack of positional accuracy. However, it is now possible to integrate high- accuracy GNSS receivers, allowing for more exact data observation.

Collector for ArcGIS didn’t allow the user to differentiate between low-precision GNSS data (such as a smartphone internal GNSS receiver) and RTK GNSS receivers Vendors offered apps that ran with Collector to display GNSS metadata, but if you wanted to record it, you would have to manually enter the metadata into attribute fields in Collector. Collector also didn’t support on-the-fly datum transformation to reconcile differences between the high-precision GNSS receiver datum and the user’s datum Last year, a new version of Collector was released that incorporates high-precision GNSS data collection and capacity for on-the-fly datum transformation. Datum Transformation

Configuring GPS with Collector

GPS Receiver Compatibility The receiver must support the output of National Marine Electronics Association (NMEA) 0183 sentences. These sentences are read by Collector to obtain positional data for an asset Most high-accuracy GPS receivers support NMEA sentence - However, they might not be configured to do so “out of the box” Receivers should also support differential GPS (DGPS) and RTK NMEA 0183 Interface Standard defines electrical signal requirements, data transmission protocol and time, and specific sentence formats for a 4800-baud serial data bus. Each bus may have only one talker but many listeners. This standard is intended to support one-way serial data transmission from a single talker to one or more listeners. This data is in printable ASCII form and may include information such as position, speed, depth, frequency allocation, etc.

GPS Receiver Compatibility If using an iOS device, only certain receivers are supported: Bad Elf GNSS Surveyor, GPS Pro, and GPS Pro+ (2.1.40 or later) CHC X20i (2.0.251 or later) Dual XGPS150A and XGPS160 (2.0.0 or later) Eos Arrow Lite GPS, 100 and 200 (2.0.251 or later) Geneq SxBlue II and SxBlue III (2.0.251 or later) Trimble R1 and R2 (5.03 and 5.14, respectively)

Supplementary Applications for Configuration 3rd Party applications are available to utilize Real Time Kinematic (RTK) or Differential GPS (DGPS) and override device internal GPS location services Configure receivers and obtain corrected positions - through a Virtual Reference Station (VRS) network or Satellite-based augmentation system (SBAS) Relies on device connectivity to internet, cellular link, and/or satellite coverage in order to download and stream corrections GNSS Status (Trimble) NMEA Talker

Supplementary Applications for Configuration GNSS Status Application Compatible with R1, R2, and PG200 Trimble Receivers Android, iOS, Windows, Windows Mobile Used by City of Hamilton to utilize ODOT VRS network through Networked Transport of RTCM via Internet Protocol (NTRIP) Network Transport of RTCM data over IP (NTRIP) is a protocol used to transport RTK correction data over the Internet. The correction data is moved in a way similar to that of streaming audio Contact for VRS account

Adding GNSS Metadata to Features You may want to capture GPS metadata associated with a feature - Data concerned with Accuracy - Data concerned with Fix Type You must add GNSS fields to features so that Collector can write data to them - Manually add fields with domains to a feature - Use a Python script to automatically add them (such as CollectorUtils)

Adding GNSS Metadata to Services GitHub Collector-Tools Download from GitHub and Unzip 2. Run “Add GNSS Metadata Fields” 3. Input Feature Class This script will add the following to your feature:

Attribute Field Name Field Type Domain Receiver Name ESRIGNSS_RECEIVER string (50)   Horizontal Accuracy ESRIGNSS_H_RMS double Vertical Accuracy ESRIGNSS_V_RMS Latitude ESRIGNSS_LATITUDE Longitude ESRIGNSS_LONGITUDE Altitude ESRIGNSS_ALTITUDE PDOP ESRIGNSS_PDOP HDOP ESRIGNSS_HDOP VDOP ESRIGNSS_VDOP Fix Type ESRIGNSS_FIXTYPE short ESRI_FIX_TYPE_DOMAIN Correction Age ESRIGNSS_CORRECTIONAGE Station ID ESRIGNSS_STATIONID ESRI_STATION_ID_DOMAIN Number of Satellites ESRIGNSS_NUMSATS ESRI_NUM_SATS_DOMAIN Fix Time ESRIGNSS_FIXDATETIME date

Datum Considerations

GPS locations are in geographic coordinates that are referenced to a geographic coordinate system (GCS) – WGS84 Your map and data may be in a GCS or a projected coordinate system (PCS) A datum transformation should occur any time coordinate systems don’t match - Between the GPS and the map - Between the map and the feature service - Between the feature service and the geodatabase A location profile can be created within Collector to specify the coordinate systems of the GPS data and the map, along with the specific datum transformation to use *ESRI basemaps in AGOL and the default coordinate system for GPS data received in Collector are both WGS84. If you are using both, no datum transformations are necessary within Collector

Step-by-Step Process * Please refer to Document “ArcGIS Collector with R2 and VRS Configuration”

Live Demo

Q&A