Standard Process of States

These are the states that a DTM goes through on its way to being perfected for a specific resolution. The state defines the quality of processing that has gone on. It does not describe all the steps that is needed to get there. That is because many steps need to be done multiple times (such as building and loading an updated shape model). Errors and problems in the data will make each DTM different in terms of what is needed to achieve the state.


Tiled means that the DTM has undergone the basic stages of latlon-tiling or bigmap_tiling. This does not have any additional processing, just the batch mode.


Correlated means that all the landmarks of the DTM are indicating a correlation score (above 0.0000). This means they do not throw the "*" error for find_nofitP.


Imaged means that there are at least 5 images for every landmark. While 3 is the minimum, 5 is needed to have a robust DTM that accounts for error. If there are not 5, then a lower number is acceptable; however, it can never be less than 3.


Fitted means that there are no maplets with more than 10 "nofits". No Fit errors are thrown when overlaps is unable to match two maplets that should overlap. This means that there are too many differences between the two maplets for SPC to find common ground. It is common for there to be a few maplets that are missing one or two of their connections with other maplets.


Residualed indicates that errors thrown by residuals. Any errors that are marked by ">>" have been corrected. Typically, you would run geometry with option 2 before running residuals. The standard input for this level is: 5 5x GSD GSD. You may choose looser values to get a smaller list first. 5 pixels -- image (or maplet) pixels. How close they are. 5x GSD, ground sample distance, 5 times the resolution of the maplets. GSD, ground sample distance


Re-tiled means that the DTM has any holes filled in. For the global scale, use coverage and look for where the missing maplets are. ZMaps can be used if available. For local scale, build a bigmap and look for regions where the maplets were deleted. You can build them missing ones by hand, or you can run the bigmap_tiling procedure.

Advanced States


Here you add images to get just as many as possible, doing processing by hand as needed. More images reduce the amount of error in the model, so adding more images will make the model better.


This is where you use tighter limits for what throws an error. Typically: 2, 2xGSD, GSD. 2 pixels -- image (or maplet) pixels. (How close they are) 2x GSD, ground sample distance, 2 times the resolution of the maplets. GSD, ground sample distance