SFCO2014 LiDAR Flight Trajectories

LiDAR acquisition of Santa Fe County was performed with an Optech ALTM Orion H300 LiDAR sensor. For quadrants 1 and 5 (composed of mountain areas with significant relief), The acquisition team flew at an average altitude of 4,039 ft AGL (above ground level) and made appropriate adjustments to compensate for topographic relief. The PRF (pulse repetition frequency) used for collection was 75 kHz, scan frequency of 42.3 Hz, and scan angle of +/- 12° from the nadir position (full scan angle 24°). For quadrants 2, 3, and 4 (primarily flatter desert areas), flights were at an average altitude of 3,250 ft AGL. The PRF used for collection was 100 kHz, scan frequency of 44 Hz, and scan angle of +/-19° from the nadir position (full scan angle 38°). The Orion H300 features roll compensation that adjusts the mirror to maintain the full scan angle integrity in relation to nadir, even when less than perfect weather conditions push the sensor off nadir. Acquisition was performed with 30% overlap and yielded an average 5.9 points per square meter. The Orion H300 LiDAR sensor is capable of receiving up to four range measurements, including 1st, 2nd, 3rd, and last returns for every pulse sent from the system. The Orion H300 is also equipped with a GPS/IMU unit that continually records the XYZ position and roll, pitch and yaw attitude of the plane throughout the flight. This information allows for correction of laser return data positions that may have been thrown off by the plane’s natural movement. The ALTM Orion H300 LiDAR sensor is equipped with Optech FMS Planner Flight Management System Software. FMS Planner is the latest release from Optech, and is not only used to guide the airborne mission in flight, flight planning is performed using the same software. This smooth transition from flight planning to aerial operations eliminates discrepancies between the flight plan and what is actually acquired. The use of FMS Planner helps ensure an accurate and consistent acquisition mission with real-time quality assurance while still airborne. The system operator can monitor the point density and swath during the mission to confirm adequate coverage within the area of interest.