To use the new GNSS (Global Navigation Satellite System) features in MVN 2019.2 ensure you first have a compatible antenna and have updated your BodyPack and Motion Tracker firmware to 1.2.0
GNSS functionality allows your BodyPack to communicate, via an attached antenna, with GPS and GLONASS satellite networks giving positional information of your actor no matter if they are on foot or traveling in a vehicle.
For setting up your Link with a GNSS Antenna follow the tutorial HERE
Points to Keep in Mind for your GNSS Sessions
- When preparing to record in a GNSS scenario ensure you are in a wide open space, away from tall buildings to ensure the most accurate data possible. Any tall buildings or high mountains in the vicinity of the recording space will negatively affect the data you obtain.
- As GNSS works best for situations where your subject is traveling in a vehicle its likely that remote on body recording would be the best approach to prevent the need to stay in range of your access point. For setting up a OBR session follow the tutorial HERE
Setting up a GNSS Scenario in MVN
- Setup your subject in the link suit as normal ensuring the antenna is secure on the shoulder and attached to the connection on the BodyPack.
- Connect your suit to MVN as normal and start a new session.
- In the Motion Capture Configuration Window find the Data tab and tick the box beside GNSS. You will now see two graphs to the right of your viewport, GNSS Accuracy Data and Global Positional Data.
Keep in mind it may take a minute or two for the BodyPack to find a stable connection with a set of satellites so the GNSS graphs may not immediately start showing data.
GNSS Graphs Explained
GNSS Accuracy Data (m)
The upper graph seen in the GNSS Data window shows the Accuracy in meters, which is a theoretical estimation of the positional uncertainty.
In an ideal recording environment, you want accuracy to be as close to 0 meters as possible. However, anything below 1 meter will give acceptable data.
This is the first graph to analyze before beginning a recording. If the accuracy is low or very inconsistent, jumping from good to bad accuracy, then its unwise to record in the current environment you are in as the data you obtain will have very poor positional consistency.
Global Measurement Data (deg)
The lower graph plots the location of your subject via there latitude and longitude.
In processed recordings, you will be able to view the full journey taken by your subject from this graph.
How the Data is Displayed Differently during Live and post Processing
If recording with GNSS enabled is in a live session, your scene will be set to No Level automatically. Until the recording has been processed the MVN avatar will not move from the point of Origin.
ROBR Gnns Activation
To activate GNSS in a rOBR session first open the rOBR window and wait for your BodyPacks to connect.
Now click on the BodyPack you wish to enable a rOBR session on and go to its configuration window on the right of MVN.
From here Navigate to the Data tab as you would in a Live session and tick the box beside GNSS.