Our strip alignment software is now able to correct the relative geometry of challenging corridor projects while preserving, or even improving the absolute accuracy of the LiDAR point clouds.

In large corridor mapping projects with very limited flight line overlap (see illustrations) default options may yield large mean corrections and a degradation of absolute accuracy. StripAlign was recently improved to help deal with these difficult situations – where adding more overlap by increasing the number of flight lines is simply not possible due to cost constraints.

New options help improve results significantly when the HF component of IMU errors is the dominant source of misalignment. In general, there is enough overlap for calibration to work correctly, and rigorous corrections provide excellent results in terms of absolute and relative accuracy.

From left to right: overlap map, group overlap map, mean z correction with –C0 -dcc -W, correction with -C0, correction with -C0 -fill 0. Note that all solutions have the same relative accuracy, but the first one has the best absolute accuracy (assessed with GCP), at least in this particular example. In general, the warp option achieves a slightly better absolute accuracy but the corrections do not follow a rigorous LiDAR equation.
The input data has misalignments of +/- 10 cm in some areas and the best correction is only a few cm.

Corridor mapping alignment