Need wrapped colormap for use with InSAR phase rasters

Question

(updated)

I am working with InSAR data which is basically a raster with float values of phase shift ranging from some negative float value to some positive float value (say -13.345 to +14.345). I want to display a wrapped colormap through equal intervals so for example from 0 to 1 displays 32 colors through a colormap, repeated from 1.0001 through 2, and also mirrored in the other direction (0 to -1, -1.001 to -2 etc). With InSAR this shows wrapped values in "bulls-eye" features that indicate subsidence or elevation of the surface.

UPDATE: I was confused about the method we were using, our current method was to create an algorithmic colormap that did a rainbow (HSV Mars Red -> Peony Pink) as many wraps as we wanted and using the classified renderer, equal interval with 256 classes. This is kind of a pain in ArcMap (not so bad once you have the ramps created). But it is still kind of klunky.

Does anyone have any ideas on how to do this?

curtvprice · Answer

I just updated the post. At lab today I discovered we weren't using discrete renderer after all, though perhaps that may be a path to get what I want since it auto-wraps. I'm thinking I may use raster functions to remap my data to integer and use the discrete renderer to get a wrapping (repeating) colormap with the data transformed to integer.

Note, since obviously discrete renderer is there in Pro, I deleted my idea post. Thanks Kory.

curtvprice · Answer

Thank you Kory, appreciate the links.

I don't know why I couldn't find the discrete renderer - I'll go back and take a look. Teaching four classes and taking another has me a little confused. 🙂

I think the idea stands because many people do work with InSAR data and there have to be other "wrapped" periodic measurer people want to map with raster data.  I'm thinking there is probably a nifty way to do this with raster functions, which I am sadly not conversant with.

KoryKramer · Answer

Curtis, I responded over on the idea thread.  That idea description didn't include specifics around wanting to do this with floating point.  The Discrete renderer is in Pro just as in ArcMap, but ArcMap didn't render floating point data either: Rendering a raster dataset with the Discrete Color renderer—Help | ArcGIS Desktop

One thought on how to fake your floating point raster into integer is to multiply by 10,000 or something like that depending on the number of digits after the decimal.  Just an idea, but you're far more of an expert than I when it comes to working with raster data