Table of Contents

Heading

This page is used when you want the receiver to deliver heading, roll or pitch measurements. The receiver can operate in one of the following two heading modes:

   Internal heading: This requires that the two GNSS antennas used be connected to the receiver via two separate inputs. In this mode, the receiver needs two GNSS boards, one to receive and process signals from “Antenna 1” (the “usual” input), and the other to receive and process signals from “Antenna 2” (the second input).

The “Antenna 1” input is the rear panel coaxial connector marked with a satellite icon.

The “Antenna 2” input is the rear panel coaxial connector marked with satellite + clock icons.

   External heading: The receiver uses its own antenna connected to the “Antenna 1” input (same as above). One of its serial port is declared as the one providing the receiver with corrections in ATOM or RTCM-3 format from an external GNSS receiver to which the second GNSS antenna (defined as “Antenna 2” on your receiver) is connected. The local “Antenna 2” input is not used here.

Combining these incoming data with the data from its own antenna, the receiver will be able to determine the heading of the baseline connecting the two antennas.

Whatever the heading mode used (internal or external), the two antennas should be installed to guarantee an ever-fixed baseline length.

 

WARNING! The heading determined by the receiver always depicts the direction of the vector defined by “Antenna 2” (vector origin) and “Antenna 1”.

 

Depending on the orientation of the baseline with respect to the vehicle centerline (ship, plane, land vehicle, etc.), the receiver will either compute the heading+pitch or heading+roll angles. The value you assign to the azimuth offset parameter will determine whether the receiver will compute the roll or pitch angle:

   Computing Heading+Pitch: The baseline should be strictly parallel (azimuth offset= 0°), or roughly parallel (azimuth offset close to 0°), to the vehicle centerline. “Antenna 1” should be placed ahead of “Antenna 2” with respect to direction of travel.

NOTE: You can reverse the locations of Antenna 1 and Antenna 2, but in this case you should enter a azimuth offset equal, or close to 180°.

   Computing Heading+Roll: The baseline should be strictly perpendicular (azimuth offset= 90°), or roughly perpendicular (azimuth offset close to 90°), to the vehicle centerline. For an observer taking a look at the antennas from the back of the vehicle while looking towards the front of the vehicle, “Antenna 1” should be seen on the right and “Antenna 2” on the left.

NOTE: You can reverse the locations of Antenna 1 and Antenna 2, but in this case you should enter an azimuth offset equal, or close to 270°.

 

If the azimuth offset is set to a value exceeding 15° from either North, South, West or East, then the receiver will deliver the heading component of attitude, but not the pitch or roll angle.

 

From the operational point of view, the receiver that uses “Antenna 1” operates as a rover while the receiver using “Antenna 2” (whether the second GNSS board inside your receiver, or an external GNSS receiver) operates as a moving base.

Activating a heading mode, whether internal or external, in your receiver will necessarily re-configure the receiver using “Antenna 1” as a rover. If it was previously set up as a base, then it will instantaneously become a rover as soon as you activate the heading mode. If it’s already a rover computing RTK positions, switching to heading mode will not impact the processing and availability of RTK positions.

 

The following groups of parameters need to be defined:

• Receiver

• Satellites

• Heading

Receiver

Parameter

Designation

$PASHS

Antenna 1

Select the model of antenna used as “Antenna 1”. Antenna 1 is the antenna connected to the coaxial plug marked with a satellite icon.

ANP,OWN

Antenna 2

Select the model of antenna used as “Antenna 2”.

In internal heading mode, Antenna 2 is the antenna connected to the coaxial plug marked with a satellite icon and a clock icon.

In external heading mode, the “Antenna 2” field should be ignored.

ANP,OW2

Fast Output

Set this option as follows:

   Check it to enable fast output of heading mea­surements.

   Clear it to disable fast output of heading mea­surements.

CPD,FST

Satellites

Use this area to define the constellations received by the receiver as well as the elevation mask applied for all constellations.

 

Parameter

Designation

$PASHS

Position Ele­vation Mask

Enter the elevation mask, in degrees, used by the re­ceiver to compute the heading. No data from any vis­ible satellite located below this elevation angle will be used in the heading measurement.

ELM

GLONASS

Check this button to enable GLONASS tracking (re­quires installed S option). Clear it otherwise.

GLO

SBAS

Check this button to enable SBAS tracking.Clear it otherwise.

SBA

Heading

Parameter

Designation

$PASHS

Mode

Make the appropriate selection:

   Off: No heading measurement requested

   Internal: Heading measurement requested, entirely under the control of the receiver and its two antennas.

   External: Heading measurement requested, external GNSS receiver and its antenna used to provide the receiver with the appropriate data.

CPD,ARR,MOD

Input Port

(Visible only if Mode= “External”) Choose the serial port through which data from the external GNSS receiver (and the second GNSS antenna) are applied to the receiver (A, B, F, C, D, E, I or P).

CPD,ARR,MOD

Baseline Length

Enter the distance between the two anten­nas used (baseline length).

Setting this parameter to “0” forces the re­ceiver to start an-auto calibration sequence.

Auto Calibration: Checking this button amounts to entering “0” in the Baseline Length field, which, as explained above, will result in starting an auto-calibration se­quence.

CPD,ARR,LEN

Azimuth Offset

Designates the angle deviation (0-359.99°) between the horizontal component of the baseline and the horizontal direction of the object for which you want to determine the heading.

This parameter makes sense in a vehicle for example where the baseline resulting from the installation of the two antennas is not parallel to the direction in which the vehicle is moving (default: 0).

Specifying the azimuth offset also allows the receiver to deliver an accurate measure­ment of the roll or pitch angle (depending on whether the baseline is oriented in a direc­tion respectively perpendicular or parallel to that of the vehicle).

Keep this parameter equal to zero if it does not make sense to define an azimuth offset in your application.

CPD,ARR,OFS

Maximum Base­line Elevation

Set the maximum value of expected base­line elevation (0-90°; Default: 15°).

CPD,ARR,PAR

Elevation Offset

Designates the angle deviation (±90°) be­tween the orientation of the baseline and the orientation of the object for which you want to determine the roll or pitch angle.

This parameter makes sense in a ship for example where the baseline resulting from the installation of the two antennas is not parallel to the orientation of the deck (de­fault: 0).

Keep this parameter equal to zero if it does not make sense to define an elevation offset in your application.

CPD,ARR,OFS

Maximum Base­line Length Error

Set the maximum error that is tolerated in the determination of the baseline length (0.001-10.000 meters)

CPD,ARR,PAR