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

2. 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

3. Background

4. 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.

5. 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

6. Configuring GPS with Collector

7. 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.

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

9. 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

10. 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

11. 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)

12. 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:

13. 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

14. Datum Considerations

15. 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

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

17. Live Demo

18. Q&A