Sitescan Image shift in AGOL shared orthos

Question

I'm new to Sitescan, so I'm still learning and maybe this is a learning curve thing, but maybe not.  It is newer software after all.

When I process drone images in Sitescan I'm fairly consistently seeing a shift in the processed ortho when shared to AGOL and viewed in ArcGIS Pro Desktop (and AGOL maps), but when I download the orthotiff and view in ArcGIS Pro Desktop I don't see the shift.  These are images processed in Sitescan using manually applied control points, but I've also seen in images processed with automatically detected GCPs.  I thought I used Reality Engine, but the settings screen doesn't seem to indicate that now, so I'm not sure, but I did include mesh generation as part of the processing.  See screenshot photos for an example.

In each of the attached images you'll see a parking lot I flew yesterday and processed in sitescan in the afternoon.  There are a number of catch basins and manholes I gps-located (after the flight) as green points, and one with a red point that I used as one of my GCP's.  In the screen shot of the AGOL shared ortho you'll see the shift I'm talking about, but in the ortho tiff I downloaded there's no shift.  You can even tell which cb's I gps-located in the center vs along the gutter line (center vs center back) if you zoom in close enough.

Drone is a mavic enterprise 3M RTK.

Any ideas @Thomas_Sweet or any other Sitescan people?  Is this a sitescan bug or user error?  Screen shots and processing report attached.  I'm happy to share the actual images and gcp file if anyone else wants to try.

Thanks!

matt

sitescan_downloaded_ortho.png

sitescan_AGOL_ortho.png

orthoflight_Aug22023-Processing_Report.pdf

Tom Sweet · Answer

Thank you for this great feedback it is very much appreciated and we will be sure the dev teams hear you  Please keep your feedback coming in.  - Tom

P√•l_Herman_Sund · Answer

To my knowledge,

* downloading results from SiteScan gives an image in the "output coordinate system". Hence no shift when used i ArcGIS Pro
* sharing to AGOL will do the WGS84 WebMercator and may introduce the shift. If you are lucky, with the right transformation parameters, you can correct it in Pro

I was pretty much surprised the first time I learned this - at my latitudes the WM is not much used and why Sharing to AGOL does not use the output coordinate system, and in AGOL also a tiling scheme - which easily may be provided, was a (negative) surprise.

Matt-Barrett · Answer

I processed the imagery in the same coordinate system that I use in Pro.  (NAD83 Stateplane HARN Massachusetts Mainland USFeet FIPS2001 (IPSG2894)).

However, I suppose it's possible the shift is due to the default web coordinate system in Mapviewer.  I hadn't thought of that.

Thanks!