can a smartphone deliver the accuracy for gis data collection?
TRANSCRIPT
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
Agenda
Project FLAMINGO – What is it?
Using the Raw Measurements API
New RINEX App – rinex ON
Results from rinex ON
Conclusion
2
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/
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
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.
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.
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.
Results from rinex ON – Number of satellites
tracked
8Both use the same chipset – Why is there a difference?
Results from rinex ON – Noise levels
9Both use the same chipset – Why is there a difference?
Results from rinex ON – Noise levels
10The noise is not dependent on elevation.
Results from rinex ON – Carrier phase
measurements
11We do not see any cycle slip due to the duty cycle in any
smartphone.
Results from rinex ON – Real-time kinematic
precision
12Very good precision utilising carrier phase.
Results from rinex ON – Dynamic test
13
Is this a viable survey tool?
14
Thank you!
Any questions?