Accuracy analysis
This section includes an accuracy analysis we have performed with Virtual-lab for you to have an idea of which accuracy you can obtain with the service
GNSS geodetic-grade receiver (static)
The purpose of this test was to assess the accuracy that can be achieved using a geodetic grade GNSS receiver and antenna in static mode (non moving platform).
| Test setup | Rover receiver | Base station |
|---|---|---|
| GNSS receiver | Septentrio AsteRx | Leica GR50 |
| Antenna | Septentrio PolaNT | Leica AR25 |
| Environment | Rooftop, open sky | open sky |
| Data length | 2.34 hours | 24 hours |
| Sampling rate | 15 second | 30 second |
| Number of epochs | 560 | 2880 |
| GPS start time | 2019 Nov 18 12:45:30.000 | 2019 Nov 18 00:00:00.000 |
| GPS end time | 2019 Nov 18 15:05:15.000 | 2019 Nov 18 23:59:30.000 |
The test setup is shown in the following picture:
The Septentrio AsteRx data has been processed with Virtual-lab with the following main characteristics:
| Processing characteristics | |
|---|---|
| Strategy | Post-Processing Kinematic (PPK) |
| Dynamics | static |
| Reference station | ICGC PLAN (17.4km baseline) |
In order to assess the results, the same data file (converter to RINEX) has been processed using Canadian Geodetic Survey of Natural Resources Canada Precise Point Positioning (PPP-AR) tool. The differences are shown in the table below:
| component | NRCAN PPP (final products) | Virtual-lab PPK | difference (vs NRCAN) |
|---|---|---|---|
| UTM_X (m) | 432640.419 | 432640.414 | -0.005 |
| UTM_Y (m) | 4583770.355 | 4583770.352 | -0.003 |
| ellipsoid (m) | 92.638 | 92.561 | -0.077* |
*Please note that we are currently working on fix for Virtual-lab so that the antenna models are properly taken in to account, this is expected to substantially close the gap between the NRCAN PPP solution and the Virtual-lab PPK.
Smartphone (non-moving dynamic)
This test intends to provide an estimate accuracy of the best accuracy that can be achieved with a smartphone in the most benign environment possible (non moving, open sky)
| Test setup | |
|---|---|
| GNSS receiver | Xiaomi Mi 8 |
| Antenna | internal |
| Environment | Rooftop, open sky |
| Data length | 7 minutes |
| Sampling rate | 1 second |
| Local time | 2019 Nov 19 12:17 |
The smartphone was colocated on the same point at which the antenna of the static test. The data was then processed with Virtual-lab with the following processing strategy:
| Processing characteristics | |
|---|---|
| Strategy | Post-Processing Kinematic (PPK) |
| Dynamics | Smartphone was not moving, but processed with kinematic stochastics |
| Reference station | IGN BCLN (16km baseline) |
