GNSS

GNSS receiver ports (there are 2 ports, GNSS1 and GNSS2) expect to receive an array with the following information:

1. Fix status

2. Fix type

   • 0: no fix

   • 1: dead reckoning only

   • 2: 2D-fix

   • 3: 3D-fix

   • 4: GNSS + dead reckoning fix

3. Longitude

4. Latitude

5. Altitude

6. Horizontal accuracy

7. Vertical accuracy

8. North Velocity

9. East velocity

10. Down Velocity

11. Speed Accuracy

GNSS array

Note

• The angle inputs are in \(degrees \cdot 10^7\) units.

• The distance inputs are in \(millimetres\) units.

• The speed inputs are in \(millimetres \; per \; second\) units.

The accuracy values are equal to the square root of the “Square error” parameter. These values are supposed to be computed by the GPS device and are used in the EKF for GNSS solution. However, in the configuration files user can choose between these ones or values set by user.

GNSS variances - 1x PDI Builder

RTK Example Block

To enable the RTK feature, the user has to modify the configuration (for more information on this, see GNSS sensor block - Block Programs section of the 1x PDI Builder user manual), and include more inputs via the S-function.

This input is called Relative Position, and requires an array of 10 elements:

1. Status: 0 is Data invalid and 1 is Data valid.

2. RelPosN: North component of relative position vector (cm)

3. RelPosE: East component of relative position vector (cm)

4. relPosD: Down component of relative position vector (cm)

5. relPosHPN: High precision North component (mm)

6. relPosHPE: High precision East component (mm)

7. relPosHPD: High precision Down component (mm)

8. accN: Accuracy of relative position North component (mm)

9. accE: Accuracy of relative position East component (mm)

10. accD: Accuracy of relative position DOwn component (mm)

High precision components must be in range -99 to 99 millimetres. The full component of the relative position vector (in cm) is given by the addition of the 2 components.

An example of this subgroup is shown below:

RTK inputs