EdThomas wrote:My error - I'm including snarc surveillance in here and should have stated so. Scanning aerial searchs will find emission sources and changes in the town/land. The former will not be found if they're turned off so aerial search is not going to be too helpful there. What aerial surveillance/search will identify are additions/changes in the land and structures. It will/may also show where things have been buried - differences in echoes between disturbed and undisturbed areas. It might help identify concealed structures and it will show changes to existing structures
I think that it was mentioned somewhere that the Fallen had the ability to spoof SNARC observation, hence why Chihiro and company needed the Seijinn.
And when you think about it, spoofing SNARC observation when you have comparable technology wouldn't be impossible. OWL is already overwhelmed by all the data he gets from his SNARCs so
no one looks at most of it. Most of the SNARC data goes unanalyzed unless someone is give reason to look at it.
I imagine that ArchAngel SNARC surveillance was in the same boat, so the Fallen spoofs the SNARCs into sending back junk data that doesn't trigger any of the Archangels' filters. Basically the hightech equivalent of planting a photo showing an empty room/hallway in front of a camera.
Chihiro and company of course quickly catch on to what's happening, but their technical skills aren't up to getting around it directly. So they create the Seijinn to find the Fallen the old fashioned way with good old detective work.