The Z values we report are measured from the top of the AeroPoints. This is because when they are used as ground control points and when manual processing is required we align images using pixels corresponding to the top of the AeroPoint.
We recommend using this data as it is a correct reading of the surface level of that point in the corresponding images.
Calculate the ground height under the AeroPoint
Suppose you need to know the height of the ground underneath the AeroPoint. In that case, you can subtract the thickness of the AeroPoint from the survey report's height data.
Download the survey report in CSV or excel format. Reduce the "NAD83 (2011) Height (m)" (usually column G) and "NAVD88 Height (m)" (usually column J) values for each AeroPoint.
- AeroPoint 1s should be reduced by 0.032.
- AeroPoint 2s should be reduced by 0.026.
I still can't do it!
We wrote these articles to equip you with everything you need to get the job done on your own, but we understand that sometimes this isn't sufficient.
If you're stuck, you can connect with our support team by clicking the support button on the top right corner of your user portal.