Some image maps are printed to express natural landscape color, but most are printed to emphasize objects seen in particular wave-lenghts of light, primarily near infrared. On color-infrared film, healthy vegetation appears in shades of red. Unhealthy vegetation appears in shades of pink, blue, or white. Clear water appears dark blue or black. Sediment laden water takes on a light blue tone.
Most cultural features appear as a steely blue-gray.
Product Delivery Format Paper Technical, Ordering, and Availability Information Contact any Earth Science Information Center or ESIC, U.S. Geological Survey, EROS Data Center for additional information or to place an order.