When installing the VBOX 3iS Single Antenna (v2) in your vehicle, you can either fix it rigidly to the vehicle using the fixing holes or secure it with a telescopic mounting arm.
Try to position the unit as close to the centre of the vehicle as possible, and make sure that it is level with the ground. If you are using the internal IMU, you should ideally mount the unit in the direction of travel (as shown in the image below). If this is not possible, you can change the orientation of the internal IMU in the VBOX Setup Software, on the Front Panel, or with the VBOX Manager.
Note: VBOX 3iS and the antenna should be mounted on the same rigid body to provide a relative reference. So for a vehicle such as a truck cabin, both the VBOX 3iS and the antenna should be fitted to the cabin body (if the cabin is air-sprung) or to the vehicle chassis.
You can mount VBOX 3iS rigidly to the vehicle via the fixing holes, ideally mid-way along the wheelbase.
Using a Mounting Arm
A flexible way to fix the VBOX 3iS rigidly in the vehicle is by using the Racelogic Mounting Arm. The three-part telescopic handle is fully adjustable to any length between 70 – 150 cm, another 20 cm can be added by extending the third section using the compression lever.
Both ends are fixed to an 8 x 13 cm plate which sits on a joint to accommodate uneven surfaces. The VBOX 3iS can then be pressed against the floor and the vehicle's ceiling, ensuring that the VBOX 3iS is fixed tightly. Another option is to use a bracket that attaches to the mounting arm, meaning that the VBOX 3iS can be fixed to the mounting arm before being installed within the vehicle. If using the bracket, it is recommended that the VBOX 3iS is mounted vertically towards the bottom of the pole for greater stability.
Please contact firstname.lastname@example.org for more information or to order a mounting arm (RLACS212-V2) and/or mounting bracket (RLACS291).
Appropriate placement of the GNSS antenna is crucial to the quality of the data that is being recorded.
Be aware of objects that can shadow the antenna or block the signal to the antenna. Some objects can also reflect signals which can send weaker GNSS signals to the antenna. This is called multipath, and these reflections can disturb the signal in an unpredictable way.
If an antenna is not mounted on a large enough ground plane, multipath reflections can also come from the ground beneath the antenna.
If you are using the antenna without a sufficient ground plane (such as on a bike or carrying the unit by hand), you can put a sheet of metal underneath the antenna (this can for example be copper or aluminium foil) or use an antenna with strong multipath-rejection properties (ACS320).
Antennas, such as the ACS320, are much larger and more expensive than the standard antennas that come supplied with a VBOX unit, but you can mount them on a pole to get them higher from the ground and away from shadowing items.
On a motorbike, you should place the antenna as far from the rider as possible to reduce the rider's shadowing effect. The best place is usually at the back of the bike.
Illustration showing multipath reflections from the ground and surrounding buildings.
When you are placing the GNSS antenna on a vehicle:
Use the GNSS antenna in the centre of a metal roof or on a metal ground plane that has a radius of at least 5 cm.
Make sure that the GNSS antenna is placed away from anything than can cause blockages or multi-path, such as roof bars or radio antennas.
Mount the antenna close to the edge of the roof as reflections from the ground may interfere with the signals.
Illustration of the recommended GNSS antenna placement location on a vehicle.
Illustration of alternative GNSS antenna placement locations on a vehicle.
For non-magnetic surfaces:
If the vehicle does not have a metal roof you can:
Use copper or aluminium foil to create a shaped ground plane that is at least 10 cm in diameter and place it underneath the antenna.
Use a Suction Roof Mount with Steel Plate (RLACS334).
Satellite Elevation Mask
You can use the Satellite Elevation Mask feature to improve the GNSS signal quality when nearby obstacles, such as trees and buildings, are reflecting or temporarily obscuring the signal from satellites at low elevation. Raising the mask will make the GNSS engine in your VBOX unit ignore signals from satellites that are located below the mask angle. As this feature will reduce the total number of satellites it receives a signal from, you must use it carefully to make sure that you have sufficient satellites for your test.
You can change the elevation mask angle in VBOX Setup or with VBOX Manager.
Connecting the Loom to the VBOX Unit
|Note: It is important that you do not use force when connecting and disconnecting the loom to the VBOX unit.|
|Push the connectors gently together and twist the outer ring on the loom's connector until it slots in place and locks the connection.|
Disconnecting the Loom From the VBOX Unit
Note the notches on the connectors as illustrated above. Twist the loom's connector while you gently pull it away from the unit.