One of the primary collection components is the SRH sensor. The sensor can be mounted on a vehicle at different angles depending on the task at hand.

Sensor

• 64 lasers/detectors
• 360o field of view (azimuth)
• 0.09o angular resolution (azimuth)
• More than one million points per second

Laser

• Class IM – eye safe
• 4 x 16 laser block assemblies
• 905 nm wavelength
• 10 nanosecond pulse

Mechanical

• 12V input (16V max) @ 4 amps
• Less than 29 lbs.
• 10” tall cylinder of 8” OD radius

Operating Conditions

• Day and nighttime operation ability
• Collection at highway speeds
• Weatherproofed to withstand wind, rain, and other adverse weather conditions.

High Resolution Digital Right-of-Way Imaging

Mandli’s road systems offer digital imaging at 1600 x 1200 resolution taken from a moving vehicle. The camera is attached to an adjustable mount inside the vehicle on the front windshield for easy access and protection from outside elements. The camera is positioned at driver’s eye level with a right-of-way view. This field of view includes the lane of travel, street signs, guide signs, mile markers, pavement markings and overhead signs. When the system has a second camera installed, this camera is also mounted at driver’s eye level, but angled to the right approximately 55 degrees. The dual camera extended field of view includes guide signs, roadside features, billboards, vegetation, and terrain. Coupled with the SRH, the ROW imaging provides a visual reference to scanned clearance data.

Positioning System

Mandli's positioning system ensures that all collected data can be measured as accurately as possible. By using GPS systems and an inertial measurements unit, the SRH data is likely to exceed any established accuracy requirements. Mandli's positioning system consists of the following elements:

Dual GPS Receiver/Antennas The system features dual GPS receivers and antennas. The GPS antennas are securely mounted on the roof of the vehicle. POS requires at least one integrated GPS receiver for accurate positioning. The system, however, comes with two receivers, and the position difference between the two antennas serves as a heading sensor, improving heading accuracy and reliability. The system uses raw GPS observables from the receiver to aid the inertial data, allowing the system to derive useful aiding data from even a single visible satellite.

Inertial Measurement Unit (IMU) The IMU is the primary sensor used to measure position and orientation differences. It outputs raw data representing 3-axis acceleration and angular rotation of the vehicle. These observations are blended with raw GPS observables and distance traveled data to derive the position and orientation solution. This system is one of the components that makes the SRH data incredibly accurate. The IMU helps guarantee that the accuracy of any measurements taken from the lidar data exceeds your expectations.

Real-time Differential GPS The POS uses the OmniSTAR differential GPS (D-GPS) system to provide real- time corrections to vehicle positioning data. OmniSTAR maintains a network of permanent base stations located throughout the continental United States. These base stations, which are located at fixed, known locations, track all GPS satellites above 5 degrees of elevation. The base stations compute pseudo-range corrections for each satellite it is tracking at an interval of 600 milliseconds. The corrections from each station are then uploaded to a geo-stationary satellite where they are broadcast out over the coverage area.

Distance Measurement Instrument (DMI)

The DMI generates a linear reference tag for each point and functions as an additional required aiding sensor for the POS by outputting pulses representing incremental revolutions of the wheel. DMI information provides a measure of the vehicle’s linear distance traveled, and is used to constrain errors in vehicle velocity and displacement. Distances are accurate to within +/- one- thousandth (0.001) of a mile per mile, and displaying the distance in miles to four decimal places.