I'm creating simple examples of raster calculation where cell values are scored using the condition function, then the resulting layers multiplied to identify where traits co-occur. The first pass is to use a DEM of our region and run a slope function, which is then scored for the condition of low slope leading to cell values of either 1 or 0. We then repeat the process using aspect, followed by another condition function (south facing).
The problem arises when I multiply the two rasters that result from the above steps. Since each raster now has cells with a value of either 1 or 0 (meets or doesn't meet condition), the product of the two rasters (using calculator) should be 1 when values in overlapping cells are 1 (1x1), or 0 if one (1x0) or both (0x0) aren't met. Unfortunately the result layer is identical to the results from the slope layer alone.
What am I overlooking? Each conditional raster layer (slope <10 and aspect south) is generated from the same source DEM. Cell sizes in east conditional raster remain identical (10m x 10m). But calculator doesn't want to create a product from slope x aspect. It simply returns the same pattern as is found in the slope layer.
I've been able to successfully complete this simple analysis in the past using ArcGIS Online with the Image Analyst extension. Why does it no longer seem to work?
- Rich
