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field_checking_your_lidar

Field Checking Your LIDAR

To field check your data it is actually pretty easy. You will need an installation of NovAtel Convert 2.0.

Open NovAtel Convert 2.0 (It will be in the Convert folder, not in NovAtel in the Programs folder). Use File::Open and browse to your Snoopy *.gps file. Open to the following view:

Just INSPVAS should be checked. Click on Convert. It will create a file with an *.asc extension of the same name as the gps file.

The first lines will most likely look like this (saying INS_ALIGNING):

%INSPVASA,1918,510042.700;1918,510042.700000000,33.81627811704,-84.44307048142,250.0076,0.0038,0.0121,-0.0211,0.000000000,0.000000000,0.000000000,INS_ALIGNING*80e55ba9

And finally changing INS_ALIGNING to INS_ALIGNMENT_COMPLETE

%INSPVASA,1918,510320.000;1918,510320.000000000,33.81590864533,-84.44288087023,296.2598,-8.7575,6.6421,1.0683,0.000000000,0.000000000,0.000000000,INS_ALIGNING*9bfca6fd
%INSPVASA,1918,510320.100;1918,510320.100000000,33.81583365215,-84.44281342522,296.5767,-6.8647,5.1221,0.3079,-0.002550696,2.309094672,142.936851795,INS_ALIGNMENT_COMPLETE*6076f24c

And then to INS_SOLUTION_GOOD

%INSPVASA,1918,510469.000;1918,510469.000000000,33.81498524002,-84.44026148451,300.4122,4.8727,3.8684,0.0327,-5.351240534,3.259014540,46.036187648,INS_ALIGNMENT_COMPLETE*be62d555
%INSPVASA,1918,510469.100;1918,510469.100000000,33.81498962614,-84.44025738375,300.4181,4.8937,3.6981,0.0684,-7.787759563,4.769907870,45.295283313,INS_SOLUTION_GOOD*23990190

Open ScanLook and browse to your project. It will find the *.asc automatically for the INS file and automatically create a *_RawEventsUTM.txt file as the INS Event file.

At this point, you need to use the Advanced option in the Boresight Settings and enter 180 degrees into the Roll field. This is because the SBAS orientation is not the same as the IE processed solution. The 180 degree roll will not be perfect but it will be close enough to see how your coverage is.

Now go generate your point cloud as normal.

You should get something like this:

It's not something you would deliver, but it gives you a good idea of your coverage.

If you want your SBAS field data to look good, an SBAS specific boresight would need to be computed. It is largely a Roll of 180 from the standard boresight plus a bit of tweaking on all three angles. It can be made to look quite good. Your strips will not line up perfectly in any case because your GPS solution is only using SBAS at best.

field_checking_your_lidar.txt · Last modified: 2016/11/09 16:52 by jeff.fagerman

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