def Resolution(self, zoom ):
		
		# return (2 * math.pi * 6378137) / (self.tileSize * 2**zoom)
		return self.initialResolution / (2**zoom)
Resolution (meters/pixel) for given zoom level (measured at Equator)
dataset/ETHPy150Open Ecotrust/create-utfgrids/globalmaptiles.py/GlobalMercator.Resolution