Coordinates
There are 2 types of coordinate systems available in Delphic Oracle: Geocentric and Topocentric. For the most part the difference will be so small as to be hardly noticable. Geocentric coordinates are based upon a location as calculated from the center of the earth. Topocentric coordinates are calculated based upon a location on the surface of the earth. There is sometimes enough parallax between these two positions to amount to about 1 degree difference in the location of the Moon of these 2 types and you should keep this in mind when calculating lunar returns.