1. A method for radiometric normalization of a plurality of mosaic image layers having different spatial resolutions, comprising: first calculating first image metadata for at least a first image portion of a base image layer of a portion of the Earth, the base having a first spatial resolution, wherein the first image metadata is independent of the first spatial resolution, wherein the first image metadata relates to the color of the base image layer; second, subsequently capturing a second image that includes at least some of the portion of the Earth, and calculating second image metadata for at least a second image portion of the second image, the second image having a second spatial resolution is greater than the first spatial resolution, wherein the second image metadata is independent of the second spatial resolution, wherein the second image metadata relates to the color of the second image; determining a normalization function based on a comparison of the first image metadata for the first image layer and the second image metadata for the second image layer; applying the normalization function to the second image layer to normalize at least a portion of the second image layer relative to the first image layer; downsampling the second image to create a third image having a resolution less than the second resolution and greater than the first resolution, and to create a fourth image having a resolution less than the third resolution and greater than the first resolution; and allowing a user to zoom between the second, third, and fourth images.