2021-12-18, 01:38 AM
I've tried using available lidar data to pinpoint the low point, but the relative noise inherent in the data collection method means that it isn't quite accurate enough at the publicly-available level. That's not saying that it's being obscured, rather that it would require analysis and know-how (software) that I don't have or know how to use.
Lidar itself does not give accurate data on elevation right off the bat. In fact it can vary noticeably from known, established benchmarks because of the resolution of the reflection points and the aerial-acquisition method has inherent noise. Your elevation model is only as good as your ground-control points and your calibration/calculation of the data.
Re: the stability of the low point… it is known to move around quite a bit. I don't know how much it changes on a year-to-year basis, but you could figure it out by flying new LIDAR. If it were acquired from a UAS ("drone") or ground-based system then you could absolutely get the accuracy and precision needed for that analysis. That'd be a huge - and largely unsatisfying - undertaking.
Lidar itself does not give accurate data on elevation right off the bat. In fact it can vary noticeably from known, established benchmarks because of the resolution of the reflection points and the aerial-acquisition method has inherent noise. Your elevation model is only as good as your ground-control points and your calibration/calculation of the data.
Re: the stability of the low point… it is known to move around quite a bit. I don't know how much it changes on a year-to-year basis, but you could figure it out by flying new LIDAR. If it were acquired from a UAS ("drone") or ground-based system then you could absolutely get the accuracy and precision needed for that analysis. That'd be a huge - and largely unsatisfying - undertaking.
Check me out on YouTube @ BetterGeology! https://www.youtube.com/c/BetterGeology
And my out-of-date website dvexplore.blogspot.com
And my out-of-date website dvexplore.blogspot.com