Positional

The positional system collects vehicle position, velocity, altitude, track, speed, and dynamics from a moving vehicle. This GNSS data can be used to create centerline maps and to calculate geometric data such as curvature, grade, and cross-slope. The POS also provides motion compensation information to other sensor systems onboard the data collection vehicle. The system incorporates a POS unit, an Inertial Measurement Unit (IMU) with real-time differential, and a wheel encoder Distance Measurement Instrument (DMI) that provides a measure of the vehicle’s linear distance traveled, and is used to constrain errors in vehicle velocity and displacement.

• Positional data is synchronized with all other collected datasets
• Integrated DMI and IMU increase accuracy of data
• Grade and cross-slope are standard outputs and are therefore highly accurate and reliable

When collecting positional data, Mandli uses real-time differential corrections, and follows up with post-processing as well. During post-processing, we can take advantage of knowing not only where the collection vehicle has been, but also where it is going. The software uses corrections from the best base station data available, and runs the IMU data and positional data in both directions, and combines both for a much more accurate X, Y and Z solution. This provides a much more accurate location for all collected data.