wherecamp berlin introduction to raw gnss measurements
TRANSCRIPT
Introduction to GNSS RAW measurementsprovided by Android NWhereCamp Berlin
Lukasz K Bonenberg
NGI, University of Nottingham
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RAW GNSS?
Figure 1: Android Nugat
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meaning?
3
Existing API
Figure 2
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New Android Nugat API v24+
Figure 3
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A challenge
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It’s hardware stupid
Figure 4 7
GNSS experts only?
Figure 5: Pseudoranges
L =T receiver
arrival− T
satellitetransmission
c8
Mass market?
• Limited hardware at this stage1
• hardware forced to comply from mid 2017
• No battery drain but..• Duty cycle - problem with clocks
• many producers, many implementation• market coverage?
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• Qualcomm Snapdragon 650, 820• Broadcom BCM4774• Intel WCS2x00
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Help is here
Google released Matlab code showing:
• example logger application• the details of obtaining pseudoragnes• calculating position
I work on python version
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What about API
• most devs focus in high abstraction - gms.location• for RAW measurements use android.location
• not so easy to use• check Matlab code for implementation details
• google . . .
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An opportunity
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Improved position
• using external corrections (DGPS)• reduce errors in urban areas (GNSS shadowing)• use sensor fusion• use carrier phase measurements?• improving on antenna ?
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Other?
• mass market applications• data collection & analysis• position quality estimation
• data fusion• . . .
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Live demo
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Useful links
• Google code• my gitHub with python code• my gitHub with edits to google code• Simon Banville blog• Rokybun blog
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Thank you
https://github.com/DfAC
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