I am looking at a large geographic area (e.g., continental Africa). I generated a raster of modeled habitat (using MaxEnt) defined in WGS 1984 depicting the hypothetical distribution of an organism at 2.5 Arc-minutes. I am looking to calculate a number of seemingly simple area statistics (using ArcGIS 10.3) but I am having trouble accounting for changes in cell sizes.
For example, I have an expert delineated range polygon shapefile with defined presence zones for the species defined in World Cylindrical Equal Area. I want to know how many pixels (and how much area in km2) of my raster are found in each of the zones, but my raster spans continental Africa. I've run zonal statistics but direct pixel counts provide inaccurate estimates of area size. I've tried projecting my raster into World Cylindrical Equal Area but subsequent error messages have deduced this is not possible.
I've thought about converting the raster pixels to a pointfile, projecting the pointfile to World Cylindrical and then counting the number of pixels per zone as defined in the expert delineated shapefile. If the pointfile and range polygon are both projected into World Cylindrical Equal Area projection would I be able to then 'sum' the number of points found in each zone delineated in the expert range shapefile and then multiply the number of points by the cell-size of the original raster (2.5 Arc-minutes)? Or am I losing information here?
I've looked around on the forum and found similar questions (particularly this one) but I'm a bit lost on how to actually generate a reliable estimate of area spanning large changes in latitude.
I'm not entirely new to GIS but I am a bit rusty.
It seems like this would be a relatively straightforward procedure as most articles I read on MaxEnt outputs report pixel percents and area coverage, but studies spanning large geographic regions must be accommodating for the change in cell size somehow.
I receive the following errors using the 'Project Raster' tool from WGS 1984 to World Cylindrical Equal Area.
ERROR 999999: Error executing function. FDO error: -2147217370 [binary_ProjectRaster] No spatial reference exists. The table was not found. [binary_ProjectRaster] Failed to execute (Project Raster). Failed at Sat Jun 18 15:18:20 2016 (Elapsed Time: 54.82 seconds)