TerraMatch is a sophisticated tool for improving the accuracy and quality of the raw laser point cloud. It compares laser data from overlapping flight or drive paths and calculates correction values for the misalignment angles as well as xyz location errors. The comparison and correction value calculation can be either based on surface matching or on different types of tie lines. Tie line matching comprises points or lines on horizontal, vertical or sloped surfaces that can be used for matching flight/drive paths to each other, but also known point or line locations that enable the adjustment of the laser point cloud to control measurements.
Especially in terrestrial mobile laser scanning, the mismatch between overlapping drive paths usally changes over time during a surveying campaign, depending on the quality of the GPS signal on different locations. This requires a fluctuating correction solution which can be achieved with control measurements and TerraMatch tie lines.
TerraMatch is also used for misalignment angle calibration which should be checked and possibly improved at the beginning of data processing. For this purpose, data is collected on a specific calibration side which offers a point cloud dedicated for the calibration task to the software. If the system includes several laser scanners, the calibration involves scanner-to-scanner matching.
TerraMatch must be accompanied by TerraScan.