You can create a 3-d view using both Photogrammetry images and ERT profiles in Seequent Oasis montaj and create views in Seequent Geosoft Viewer. Quite a steep learning curve as complex and expensive software but results are excellent.

Before proceeding to answer this question I think I need to first bring it back to perspective that 2D ERT data is in depth section format i.e. x-z or y-z and surface imagery is in x-y format. If we both agree on this, then the only thing you might really need from your surface imagery should be the elevation data along the corresponding x or y direction. If I have not misinterpreted your question, then why not make use of point elevation (maybe from DEM) instead of the surface imagery. Though, if your data are series of 2D ERT profiles parallel or almost parallel to one another, then you can follow the recommendations of Val Donazzolo

You should also not forget that ERT models present apparent resistivities and not elevation/surface undulations when comparing the 3D views of your surface imagery and ERT.

But then, if I got your question wrong I am sorry about that. Thank you.

You can try using rockwork to integrate your ERT result with surface imagery. This is one of example to overlay surface imagery with subsurface model using rockwork : https://youtu.be/rm3Z4Lz3LUo

I hope it helps

Yes, it is possible to combine ERT profiles with high-resolution surface imagery derived from photogrammetry to better understand the study site. This can be done by georeferencing the ERT profiles and integrating them with the surface imagery in a geographic information system (GIS). Here are the steps you can follow:

By integrating the ERT profiles with high-resolution surface imagery derived from photogrammetry, you can gain a better understanding of the geological features and subsurface properties of the study area. This can help you to make more informed decisions about site characterization and remediation efforts.