Part II: Section B
Using GPS Technology
4.1 Equipment

This test was performed using the Magellan SporTrak Pro® and the Trimble Pathfinder Pro® XR. The manufacturer’s list price for the Magellan SporTrak Pro® is $300 but you can buy units from discount sporting goods stores for about $250. The manufacturer’s list price for the Trimble Pathfinder Pro® XR is $10,000. A summary of key features for each unit is described in Table IIB-1. The Pathfinder Pro series GPS units typically are used for resource surveys and, in addition to being much more versatile, are equipped with a sophisticated data logger that allows the user to record information during the surveys.

Table IIB-1: Key features of selected GPS receivers

Trimble Pathfinder Pro XR
Magellan SporTrak
Reciever: 12 channels, Carrier frequency 1 in, L-band/Coarse Acquisition code tracking with carrier phase filtered measurements 12 channels
Update Rate: 1 Hz 1 per second, continuous
Differential Ready (DGPS): WAAS differential correction capabilities WAAS enabled for up to 3 meter accuracy
Receiver and antenna specifications:
  • External antenna
  • Integrated GPS/Beacon receiver
  • Radio Technical Commission for Maritime Services (RTCM) input/output
  • 3-meter antenna cable
  • Base data-logging mode
  • Integrated GPS/Beacon antenna
  • RTCM input/output
  • Internal antenna
  • Antenna: Quadifiler Helix
  • Submeter + 1 ppm on a second-by-second basis (horizontal)
  • Submeter + 2 ppm on a second-by-second basis (vertical)
  • Less than 7 meters
Carrier Phase Processing:
  • 30 cm + 5 ppm with 5 minutes tracking satellites
  • 20 cm + 5 ppm with 10 minutes of tracking satellites
  • 10 cm + 5 ppm with 20 minutes tracking satellites
  • 1 cm + 5 ppm with 45 minutes tracking satellites (with cm processing option)
RTCM Satellite Differential Correction: Better than 1 meter 0
Display Size (screen): 10.2 by 51. by 2.1 inches 2.3 by 1.4 inches
Display resolution: 320 by 240 pixels color touch screen 160 by 104 pixels
Battery Requirements: NiMH rechageable pack, 3800mAh gives continuous operation for over 30 hours of recharges to 90% of capacity 2 AA Batteries
Battery Life: Rechargable system batteries (8 hours of field use) 14 hours
Data Storage: 2MB (storage), memory extension through user accessible PC card slot 1 MB
<< previous page  
1. What is GPS?
2.How Does GPS Work?
3. Instuctions for Using SporTrak GPS Recievers
4. Performance Testing
- 4.1 Equipment
- 4.2 Field Test
- 4.3 Test Results
- 4.4 Conclusions
5. Glossary
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