Take the 2-minute tour ×
Geographic Information Systems Stack Exchange is a question and answer site for cartographers, geographers and GIS professionals. It's 100% free, no registration required.

I have 30 overlapping maps that contain tree density heights (measures between 1-100%) of a large area, and I need to get the highest point by pixel and create a new map with all these highest points if it makes sense.

Basically, say in point (pixel) "A" in map 1, 2...30 the maximum elevation is 25 m, and in the next pixel "B" (in all the other maps) is 20. I would need to create a new map (a new matrix) that condenses all these elevations/densities (and will look like 25, 20, x, y, etc).

Someone has suggested making a program to analyze all of the maps by pixel, but I'm new to this, so any help, or suggestion will be appreciated.

Ok, based on a comment I got, I'll add more detail here about the data: I have the data in three different formats (the same data) these being tif, .dtm. and ASCII. I have a section of a river, and the 30 maps overlap on top of each other exactly. They have measurements of three density (0, where there is no "vegetation" in the pixel, to 100, all is vegetated), now each of these overlapping maps contain this same density (0-100) for different heights, namely 1-30m. For example: in map 1, I would have calculated already from another program the points between the "bare ground" and 1m, so my map "1" contains everything ABOVE 1m, my map 2, will contain everything after 2m, etc until reaching 30m.

From these maps, I'll need to produce a map with the highest three height by pixel.


share|improve this question
add comment

1 Answer

you haven't said what format the maps are in, but assuming they are (or can be) ESRI raster grids with the same extent, the following should work in ArcGIS:

Highest Position (Spatial Analyst)


Determines on a cell-by-cell basis the position of the raster with the maximum value in a set of rasters.


share|improve this answer
Hi sorry, I have the files in an ASCII format, tif and .dtm –  Alex Nov 13 '13 at 18:20
Should be an easy solution, but can you describe the data format in more detail (probably best in the original question)? What is the data source? Are all 30 maps the same extent? What format are they in (ASCII, tif and .dtm sound like at least two different types)? Also post a sample or example of the data, if possible. –  toms Nov 13 '13 at 21:00
HighestPosition does not answer this question: the O.P. is asking for the local maximum of each cell. –  whuber Nov 14 '13 at 16:53
add comment

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.