Presentation made by Spirent

1. “GNSS Raw
Measurements: From
research to commercial
use”
GSA, Prague. May 2018

2. 2Spirent Communications PROPRIETARY AND CONFIDENTIAL
Who needs Raw measurements
 Opens up a world of opportunity to developers
 Handsets
 Application developers
 Academia
 GIS data collection?
 Surveying?
 Test Tool developers
Ref: GSA Raw Measurements Whitepaper

3. 3Spirent Communications PROPRIETARY AND CONFIDENTIAL
Raw measurements to validate advanced test tools

4. Truth Analysis of Android
Raw Measurements using
GNSS Simulators

5. 5Spirent Communications PROPRIETARY AND CONFIDENTIAL
Isolate the problem you want to focus
• Antenna polarization
• precise satellite orbit and clock corrections to be
downloaded from external source
• Tropospheric delay was computed based on temperature
and pressure values
• Ionospheric delay was mitigated by using a global
ionospheric map
• satellite orbit eccentricity
• Earth tides resulting from the gravitational pull of the
sun and the moon
• carrier-phase wind-up effect
Ref: GSA Raw Measurements Whitepaper

6. 6Spirent Communications PROPRIETARY AND CONFIDENTIAL
The setup
Android App that extracts
raw measurements and reports
real-time
Real-time analysis of the raw measurements
compared to the truth
RF simulated data
RT data analysis

7. 7Spirent Communications PROPRIETARY AND CONFIDENTIAL
Multipath scenario
 DUT at handheld level, next to a building with a slight overhang and with parked
cars in the street
 Most paths are two or three bounces in length

8. 8Spirent Communications PROPRIETARY AND CONFIDENTIAL
Analyze data

9. 9Spirent Communications PROPRIETARY AND CONFIDENTIAL
Analyze data
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10. Thank You & Questions
Contact:
Ajay Vemuru
Business Development
ajay.vemuru@spirent.com