Hi,
I have an old flight which I need to replicate. Here is the situation:
We are trying to measure subsidence in an area. In order to do so we want to have 2 or more flights we can overlay. We would rather not have to clip it or in some other way process it in ArcGIS. Then we can do an exact comparison.
I can’t work out how to do so. When I go to the old flight from June in my projects and hit “fly” it throws me right back to the editor with a blank flight. The old flight grid is no where to be seen. I have poked around the docs and the forum and I did find a similar post from a couple of years ago but the thread died with no resolution.
Can someone point me in the correct direction on this?
In the old UI, you had to copy a flown flight and then it would be available to fly again as a “new” mission. Regardless, flying the exact same mission is not necessarily the way to get georeferenced layers that will line up exactly. For that you need a GCP workflow or at the least, specifying some control points like acquired from QGIS. (If I’m understanding you correctly, that is.)
@PJLopez, how’s it going with this? Hope all is well on your end.
I actually had a project that I have been running for about 3 months now that I decided I wanted to line it up and get some semblance of earthwork after the fact that I did not set GCP’s. I basically used the first ortho I flew of the entire site preconstruction, downloaded it into QGIS at 0.8in/px and located points on the ground horizontally that were pre-existing and very unlikely to change. I then used the Google Earth Survey Plug-In that allows for more accurate capture of the GE ortho heights and applied those elevations to the points that I exported from QGIS. I call them GECP’s internally. This operation is handy when you want your maps to line up perfectly and be relative to each other both horizontally and vertically, but it is not the same as putting in professionally surveyed GCP’s that are needed to tie to spcific survey and design elevations.
As you see my map-to-map relativity is going to be really good with the GCP’s tieing in well and the SFM RMSE’s are much better than you would normally get without any control. This has been a really good workflow when working with several of the GIS departments locally for master planning.
