| Scan | 1 | 2** | ||||
|---|---|---|---|---|---|---|
| Boom | 7m | 17m | 27m | 7m | 17m | 27m |
| x | 3085324.03145666 | 3085323.65345666 | 3085323.27145666 | 940408.628956629 | 940408.510956626 | 940408.390456623 |
| y | 1770315.92132804 | 1770316.34532804 | 1770316.87582805 | 539593.375328018 | 539593.509828022 | 539593.672828027 |
| z* (m) | 5.56701614659823 | 15.8755162416765 | 26.0945163359288 | 5.54405297354083 | 15.8570532856115 | 26.0755535948222 |
| lat | 39°56'52.575" | 39°56'52.579" | 39°56'52.584" | 39°56'52.575" | 39°56'52.579" | 39°56'52.585" |
| lon | -105°11'44.494" | -105°11'44.499" | -105°11'44.504" | -105°11'44.495" | -105°11'44.5" | -105°11'44.505" |
| az (deg) | 358.325803427737 | 358.671842595833 | 0.342652209509851 | 358.406401013538 | 358.387795349662 | 0.142644044710664 |
| pitch (deg) | 0.109767611226856 | -0.192215340858511 | 0.559043450656589 | 0.398341787010092 | -0.521512160530745 | 1.80623368783019 |
| roll (deg) | 0.995349254442227 | -1.8113964174835 | 5.3250072590622 | -2.94438519054225 | -1.6249548877957 | 0.55234667489206 |
*Heights are probably short by 0.5 m because of the unknown height of the trailer bed above the ground
**Scan 2 values are in meters, instead of the US survey feet used in scan 1. Converting these values into US survey feet is necessary for lat,lon transformation. Fun fact: if you transform the values in meters, you end up in the Grand Canyon.
The coordinate system used in these scans is: CO C NAD83 G18 EPSG: 6428
The website used to transform coordinate systems is: https://epsg.io/transform#s_srs=6428&t_srs=4326&x=3085323.1943564&y=1770316.9082700
Some observations:
- The average difference in height between the scans is ~2 cm, which is near the accuracy limit of the Leica
- The average difference in boom angle between the scans is ~0.2 degrees
- The differences in pitch and roll between the scans varies between 0.29-1.25 degrees and 0.19-4.77 degrees, while changing signs in one instance
- We were skeptical of our measurement (especially in roll) of the 27m sonic from the first scan because we may have been measuring one of the transducer spars instead of the transducer ball
- It's possible this error may have been reproduced for the 7m sonic in scan 2, as it's difficult to properly site the transducer ball from all angles and at all heights
1 Comment
Matt Paulus
Based on my discussion with Steve, we should consider adding some sort of marker on the sonic booms as a target for Leica measurements. Having a specific marker in the center will help with the consistency of pitch measurements.