There are several posts related to this topic on the ArcGIS forums, as well as here. However, I can still not wrap my head around this: I want to project a land cover raster provided in GCS WGS84 to an equal area projection and accurately calculate the area in hectares.
The land cover layer metadata (accompanying text file) states that it has a 300m resolution, by which I assume they mean 300m equivalent at the equator, since it is currently projected in WGS84. Manually measuring the cell size near the equator seems to indicate that this could be true.
I want to do the seemingly simple task of projecting it to an equal area projection centered on my region of interest (5 to 35 North Lat., 96 East Long.).The issue arises when I want to choose the cell size. The project raster tool suggests a cell size of ~304.xxxx meters.
I will eventually need to combine this with another rasters, which have different resolutions (all in WGS84; 0.0008333, 0.008333, or 0.083 degrees per cell, depending on the layer). I cannot accept a default cell size, as each layer will have its own default and not line up. (although, I could combined them using the WGS84 layers and project them after to calculate the area).
My question is: How can I choose a 'correct' cell size for each layer? Can anyone recommend the best practice for choosing a common cell size and projecting from WGS84 to equal area? When I set a forced cell size, e.g. 300m for an output, projected cell size, will this give an accurate area?
If I clip each raster to a bounding area, resample to the same resolution (in degrees), project one, then project all the others while using the first one as a snap raster will this provide accurate results?
Two older posts suggest projecting or using a raster calculator equation that incorporates the latitude. Does this make sense or is there a better way to achieve this goal: