History And The Present Of Satelite Images
The first ever satelite images of Earth were taken on August 14, 1959. They were taken by the US satellite Explorer 6. Almost all the satellite photography and satelite maps that are produced by NASA are publicly published by Earth Observatory. Apart from many satelite view programs by different countries, there are also many private companies that have programs for aerial maps and provide commercial satelite images. It was somewhere in the early 21st century when satelite images became extensively popular and easily available as affordable and easy to use software for satelite maps and satelite photography with easy access to satellite images databases were offered by several organizations and companies. Today the condition is such that free and detailed satelite images are offered by many websites. Infact some websites are even claiming to provide real time satelite images very soon.
There are many uses of satelite images. Satelite photography can be utilized to produce composite descriptions of any hemisphere or the entire earth. You can also use aerial maps to map a little and specific area of the Earth. So if you can take images of the countryside of Kansas, Haskell County, and United States then it can find various and numerous applications in different fields like agriculture, forestry, geology, biodiversity conservation, education, regional planning, military intelligence and warfare. Satelite images can be taken in visible colors as well as in other spectra. Using satelite photography you can also have elevation maps that are usually made by using radar imaging. Then you can interpret and analyze the satelite imagery using commercial software packages like ENVI or ERDAS Imagine. United States of America Government and its contractors were one of the very first nations to conduct the first image enhancement of satelite photographs. As for example it was ESL Incorporated, which developed some of the most primitive two-dimensional Fourier transformations that can be applied to digital imagery processing to process photos by NASA and also be used in national security applications. The resolution of these satelite images will vary depending on the accuracy of instrument used and also on the altitude of the particular satellite's orbit. As for example, the Landsat archive can offer frequent imagery at around 30-meter resolution for the planet. Then there are also cases where images with resolution as high as just 10 cm have been taken for comparatively smaller areas. Satelite images are sometimes accompanied by aerial photography, which has a comparatively higher resolution, but is also quite expensive. Satellite photography can also be combined with raster or vector data in a GIS but the only condition is that the images should have been spatially rectified in order to be properly aligned with other data sets. |