Geiger-mode LiDAR Technology
Breakthrough LiDAR collection technology delivers high accuracy and increased detail.
How Geiger-mode LiDAR Works
Large AreaHigh-density Collection
Our sensors are photon-counting devices capable of detecting single photons through the use of a highly efficient, compact photodiode array. This dramatically reduces the laser pulse energy requirements over linear LiDAR sensors, allowing our designers to build systems which fly at higher altitudes than linear sensors, meeting the same density and accuracy specifications that linear sensors are achieving at lower altitudes. This capability allows the program to collect data at higher densities, reduce the amount of flying, and increase the efficiency of the data acquisition.
Advanced LiDAR Data Collection
Collection Geometryand Rate
The Geiger-mode LiDAR sensor uses a conical Palmer scan pattern produced by a direct drive, hub driven, holographic element scanner. This conical scan pattern, combined with a 30° scan angle (full) and flight swaths flown with 50 percent side lap, provides four looks. This significantly increases the interpretability of the point cloud and offers additional benefits such as the elimination of shadowing around buildings.
Enhanced Accuracy Calibration
The calibration of Geiger-mode LiDAR data is similar to the aerotriangulation process used in photogrammetry, and therefore offers a robust solution to achieving high accuracy at altitudes exceeding the limitations of linear sensors. During initial processing of Geiger-mode LiDAR data, internal point cloud geometry (precision) is greatly improved throughout the entire point cloud in all three axes with no manual intervention, relying only on robust mathematical equations to solve for errors. Tie points are generated by automatically matching ground features between different swaths. These tie points are then used in conjunction with manually identified survey ground control points in a sensor model-based bundle adjustment process to refine the GPS smoothed best estimate of trajectory (SBET) solution. The data is then retransformed from sensor to ground space using this updated SBET to produce the final data products.
Advanced LiDAR Products
Point Cloud Generation
After calibration, the adjusted solution is then used to re-project the raw sensor frames from all four looks into ground space tiles to create aggregate data tiles at the specified output resolution (density). These tiles are then automatically re-projected to the required datum and cut into the final seamless customer tiles. As long as the acquisition parameters for any specified resolution are met, this process can allow for the generation of multiple resolutions from a single flight of data.