Performance specifications
This chapter describes all sensors and navigation system performance specifications.
Note
Performance specifications are specified in RMS unless otherwise stated.
Inertial Measurement Unit specifications
As an IMU is the main component of an inertial navigation system, the new Ellipse IMU has been carefully designed to take full advantage and performance of MEMS technology.
| Parameter | Gyroscope specification | Accelerometer specification | |
|---|---|---|---|
| Sensor Range | Marine | ±450 °/s | ±8 g |
| Land/Air | ±450 °/s | ±20 g | |
| High dynamics | ±1000 °/s | ±40 g | |
| Random Walk | 0.18 °/√h | 57 μg/√hz | |
| In run bias Instability | 8 °/hr | 14 μg | |
You can find the full specifications of the IMU on this page.
GNSS receiver specifications
The Ellipse-N and Ellipse-D embed a GNSS aiding sensor with the following specifications:
| Item | Specification | Remarks / condition |
|---|---|---|
| Signal tracking |
| All constellations and signals enabled by default |
| Horizontal position accuracy | Single point: 1.5 m SBAS: 1.0 m RTK: 1 cm + 1ppm | |
| Velocity accuracy | 0.05 m/s | |
| Dual antenna heading accuracy | 0.55° (baseline > 0.5m) | Ellipse-D only |
| 0.4° (baseline > 1m) | ||
| 0.3° (baseline > 2m) | ||
| Time to first fix | Cold start < 24 s | |
| Output frequency | 5 Hz | |
| Differential corrections input | RTCM V3.3 | Sent on any serial port |
Note
GNSS performance depends on atmospheric conditions, baseline length, GNSS antenna, multipath conditions, satellite visibility and geometry.
Ellipse AHRS orientation performance
| Performance | Remarks | |
|---|---|---|
| Measurement Range | 360° in all axes, no mounting limitation | |
| Roll / Pitch Accuracy | <0.1° | Low dynamic conditions - No long term accelerations |
| Yaw Accuracy | 0.8° | Clean magnetic environment - Magnetic calibration performed |
Ellipse INS orientation and navigation performance
This section applies to ELLIPSE E, N and D sensors, with GNSS aiding available.
- SP refers to Single Point mode and is the default standalone L1/L2 fix quality
- RTK stands for Real Time Kinematics with a typical 1 cm accuracy position
- PPK stands for Post-Processed Kinematics using Qinertia
Land applications
All specifications are valid with DMI (odometer) aiding for typical land application trajectories.
| Outage Duration | Positioning Mode | Position Accuracy | Velocity Accuracy | Attitude Accuracy (°) | |||
|---|---|---|---|---|---|---|---|
| Horizontal | Vertical | Horizontal | Vertical | Roll / Pitch | Heading | ||
| No Outage | SP | 1.2 m | 1.5 m | 0.05 m/s | 0.05 m/s | 0.1° | 0.2° |
| RTK | 0.01 m | 0.02 m | 0.03 m/s | 0.03 m/s | 0.05° | ||
| PPK | 0.01 m | 0.02 m | 0.02 m/s | 0.02 m/s | 0.03° | 0.1° | |
| 10 s | SP | 1.7 m | 2 m | 0.1 m/s | 0.1 m/s | 0.1° | 0.2° |
| RTK | 0.8 m | 0.8 m | 0.1 m/s | 0.1 m/s | 0.05° | ||
| PPK | 0.1 m | 0.1 m | 0.05 m/s | 0.05 m/s | 0.05° | 0.1° | |
| 60 s | SP | 7 m | 7 m | 0.1 m/s | 0.1 m/s | 0.15° | 0.3° |
| RTK | 5.5 m | 5 m | 0.1 m/s | 0.1 m/s | 0.1° | ||
| PPK | 1 m | 1 m | 0.1 m/s | 0.1 m/s | 0.08° | 0.2° | |
Airborne applications
| Positioning Mode | Position Accuracy | Velocity Accuracy | Attitude Accuracy (°) | |||
|---|---|---|---|---|---|---|
| Horizontal | Vertical | Horizontal | Vertical | Roll / Pitch | Heading | |
| SP | 1.2 m | 1.5 m | 0.05 m/s | 0.05 m/s | 0.1° | 0.2° Dynamic or Dual antenna baseline > 2m |
| RTK | 0.01 m | 0.02 m | 0.03 m/s | 0.03 m/s | 0.05° | |
| PPK | 0.01 m | 0.02 m | 0.02 m/s | 0.02 m/s | 0.03° | 0.1° |
Marine & Subsea applications
| Outage Duration | Positioning Mode | Position Accuracy | Velocity Accuracy | Attitude Accuracy (°) | |||
|---|---|---|---|---|---|---|---|
| Horizontal | Vertical | Horizontal | Vertical | Roll / Pitch | Heading | ||
| No Outage | SP | 1.2 m | 1.5 m | 0.05 m/s | 0.05 m/s | 0.1° | 0.8° magnetic heading 0.5° Dual antenna baseline > 0.5m 0.2° Dual antenna baseline > 2m |
| RTK | 0.01 m | 0.02 m | 0.03 m/s | 0.03 m/s | 0.05° | ||
| PPK | 0.01 m | 0.02 m | 0.02 m/s | 0.02 m/s | 0.03° | 0.1° | |
| 10 s | SP | 3 m | 3.5 m | 0.15 m/s | 0.15 m/s | 0.1° | 0.8° magnetic heading 0.5° Dual antenna baseline > 0.5m 0.2° Dual ant, baseline > 2m |
| RTK | 1 m | 1 m | 0.1 m/s | 0.1 m/s | 0.05° | ||
| PPK | 0.1 m | 0.1 m | 0.05 m/s | 0.05 m/s | 0.05° | 0.1° | |
Heave performance (Marine version)
| Real Time Heave | Remark | |
|---|---|---|
| Range | 50 meters | |
| Period | 0 to 20 s | |
| Accuracy | 5 cm (or 5% of swell) | Whichever is greater; Velocity aiding available, or no turn or speed change. |
| Mode | Real time, auto tuning |
Note
Ship motion recordings including Heave information are only available in Ellipse marine versions.
Dead reckoning specifications
The following performance applies for the Ellipse used for multiple minutes of navigation without GNSS input with adequate velocity aiding for each application:
| Position accuracy | |
|---|---|
| Land | 0.5% traveled distance |
| Marine | 1.0% traveled distance |
| Air | 2.0% traveled distance |
For more details on which aiding is the best suited to achieve this level of performance with your Ellipse in your application, contact our support team.
Traveled Distance
The spec in long dead reckoning is expressed in the percentage of the Traveled Distance (%TD) during the time without access to GNSS.
For example, for a car travelling at 60km/h, 5km will be traveled during an outage of 5 minutes. This leads to a drift of 25meters (0.5% of 5000m).