Satellite imagery...

Satellite Imagery: Satellite imagery can help scientists to report developing storm systems and changes in the ecosystem. Satellites can provide the images of the weather, day or night, through infrared image technology. An infrared satellite image indicates the pattern of heat or infrared radiation, discharged from the Earth. Images seen on the Television weather broadcast are infrared images. The Earth radiates heat into space all the time. Infrared imagery shows different temperatures in black, white and shades of gray. The coldest temperatures appear white and the warmest as black, on the satellite color scale. Since the crests of higher clouds are very cold, they show up on the infrared image as white. Lower clouds in the atmosphere are warmer and hence they feature in a darker shade of gray.

Free Satellite Imagery: Free space imagery is used in geomorphology. The Satellite divides earth into 237 plates, each plate indicating a specific geographic region. Commentary, photographs, locator maps and sometimes a geologic map, accompany each plate. Technology has advanced greatly and now satellite images are available for free, for research and inquiry. The free satellite imagery available to arms control groups, human rights activists, environmentalists, news media organizations and even the governments that cannot afford to launch their own reconnaissance satellites has helped to identify surprise attacks, famines and other catastrophic events at the earliest.

Many Governments have exercised shutter control to monitor Satellite imaging. Shutter control is the act of disrupting imaging over a given geographic area, for a given period of time. If a satellite has no other function, the government exercise of shutter control establishes prior restraint on the publication of the image.

Live Satellite Imagery: Natural hazards are monitored using live optical and radar satellite imagery. A new generation of high resolution optical commercial satellites provide imagery like IKONOS, launched in 1999, with 1m resolution in panchromatic mode and 4 meters in multi-spectral. IKONOS enables the viewing of features like buildings, streets and cars, with a high ground resolution. In future, with the next generation technology for live satellite imagery already in the making, an incredible under 1m resolution of Quickbird satellite will be accessible for civil applications, implementing 0.61 meters in panchromatic mode and 2.8 meters in multi-spectral. The technology makes possible a reliable damage detection system.

Damage detection involves the comparison of the reflectance and the texture, between two multi-spectral images, before and after an earthquake. Normally, the urban zones present an average level of reflectance in the infrared wavelength, along with a high level of intensity. After the collapse, the intensity level decreases, while the reflectance increases due to absence of the shadows. The damaged zones can be extracted by a visual comparison of two images, before and after the earthquake or by an automatic classification system.

Real time Satellite Imagery: NASA offers real time satellite imagery with the help of the Live World wind satellite imagery maps. World Wind lets you zoom from satellite altitude to any place on earth. Equipped with the Land-sat satellite imagery and Shuttle Radar Topography Mission data, World Wind enables you to view a 3D image of the earth.

Satellite Imagery maps: Satellite maps are helpful tools, since they give the user a bird's-eye view of residential areas and other areas of concern. Google Earth blends satellite imagery, maps and the power of Google Search, to put the latest world geographic information on your desktop. Google has added high-resolution satellite images to its maps and local search services. Yahoo Maps are far more interactional and geared for helping the user to search for local information and business.