Can a Smartphone deliver the accuracy for GIS data collection?
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The document summarizes initial findings from the FLAMINGO project on using smartphones for GIS data collection. It discusses (1) how the project aims to develop high-accuracy GNSS services for mass market users, (2) a new RINEX app called "rinex ON" that writes raw GNSS data to RINEX files and provides visualization tools, and (3) results from testing rinex ON which show smartphones can track satellites and measure signals accurately enough to enable real-time kinematic positioning within centimeter-level precision.
Can a Smartphone deliver the accuracy for GIS data collection?
- 1. Can a Smartphone deliver the accuracy for GIS data collection? Initial findings from the H2020 FLAMINGO project. Joshua Critchley-Marrows and Marco Fortunato, NSL 30/05/3018 GSA Headquarters, Prague GNSS Raw Measurements: From research to commercial use
- 2. Agenda Project FLAMINGO – What is it? Using the Raw Measurements API New RINEX App – rinex ON Results from rinex ON Conclusion 2
- 3. Project FLAMINGO – What is it? 3 Fulfilling enhanced Location Accuracy in the Mass- market through Initial GalileO services 9-organisation collaborative venture Development of a high accuracy service and solution for mass market users PPP and RTK infrastructure, products, service provision and user solution Facilitate consumer uptake 3 city, long-duration demonstration events Dedicated hackathon and participation in other hackathons Supporting other initiatives, eg Task Force Please sign up for news at https://www.flamingognss.com/
- 4. Using the Raw Measurements API 4 Three fundamental classes: GnssMeasurement, GnssClock, GnssNavigationMessage. Provide many functions, but not all necessary for calculations What we identify to be the most important features: Hardware GnssMeasurement GnssClock Automatic gain control Svid Bias nanos Carrier phase measurements Accumulated delta range in metres Full bias nanos Doze control Constellation type Time nanos Duty cycle control State Multiple constellations Pseudorange rate m/s Cn0DbHz Received sv time nanos Time offset nanos
- 5. Using the Raw Measurements API 5 Calculation of a pseudorange (as taken from the GSA White Paper) GPS Time Pseudorange Narrow time ambiguity of signal code lock (e.g. 100 ms Galileo), can cause result to move to next ambiguity. Selection of initial FullBiasNanos is important as must wiat for the clock to synchronise. FullBiasNanos may be kept constant otherwise time between epochs not constant, may lead to slip.
- 6. New RINEX App – rinex ON 6 Written by NSL as part of the FLAMINGO project. An ongoing development as the project progresses. We welcome any comments on the app’s performance. Includes: RINEX Observation and Navigation Message File writer. Can choose constellations. GNSS skyplot and satellite planner in 24-hour timescale. Signal-to-noise (signal strength) graphic. Satellites tracked and measured monitor. File size monitor.
- 7. New RINEX App – rinex ON 7 Marker placement Used as a survey tool. When user is at position of interest, insert marker with RINEX file. Also can be activate via a selfie stick so that the handset is away from the body.
- 8. Results from rinex ON – Number of satellites tracked 8 Both use the same chipset – Why is there a difference?
- 9. Results from rinex ON – Noise levels 9 Both use the same chipset – Why is there a difference?
- 10. Results from rinex ON – Noise levels 10 The noise is not dependent on elevation.
- 11. Results from rinex ON – Carrier phase measurements 11 We do not see any cycle slip due to the duty cycle in any smartphone.
- 12. Results from rinex ON – Real-time kinematic precision 12 Very good precision utilising carrier phase.
- 13. Results from rinex ON – Dynamic test 13
- 14. Is this a viable survey tool? 14 Thank you! Any questions?