Tools to correct the Flight line miss-alignments

[mahipal reddy]

Hi,

I am new to the lastools. Do we have any tools to perform any flight line miss-alignments/miss match corrections.

Regards,

Mahipal

 

[Martin Isenburg]

Hello Mahipal,

there is currently no tool in LAStools that can do what - for example TerraMatch - can do, namely flightline alignments using the original trajectories to account for errors in the roll / pitch / yaw of the IMU data and/or errors in the x/y/z GPS location. We have, however, created the DQM (Data Quality Metric) tool for the USGS and this output correction vectors for all planar areas in the area where the flightlines overlap. Eventually we may use some of these results to produce a "best effort" repair without trajectories.

What we currently have is a new option in 'lascontrol' that - given a set of control points - will shift the LiDAR vertically to minimize the average z error.

http://rapidlasso.com/lascontrol

http://lastools.org/download/lascontrol_README.txt

Regards,

Martin @rapidlasso

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[Steven F]

There are a few other software solutions you can use to correct for misalignments until lastools implements a correction tool.

If you only want to match two flight lines you can try the Iterative Closest Point matching in CloudCompare (which is free). If you want to match a set of flight lines you can try the Georef package in OPALS. Neither of these use the flight trajectory data in the alignment process.

[André Jalobeanu]

Hi,

We are currently launching the first version of BayesStripAlign, please check out this page for more information:

http://bayesmap.com/?page_id=373

It aligns LiDAR swaths automatically, correcting relative and absolute errors, with our without control points. It also performs calibration from regular flight lines.

It uses dense matching, no planar or man-made features required, and it is fairly robust to vegetation.

Currently it is designed to work with airborne LiDAR surveys, but it might also work with low-altitude UAS surveys.

It takes LAS/LAZ files and trajectory (text/POF/SBET) as inputs, and writes the corrected point clouds, as well as a number of quality check results, such as z-difference images, z-difference histograms and local error metrics. 

There is a 30-day trial period (fully functional software) and academic pricing is available. 

André Jalobeanu, founder

BayesMap Solutions, LLC