can a smartphone deliver the accuracy for gis data collection?

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?