The Evolution Of Live Satellite Imagery
There's only so much that can be seen through a map. You can know what the person who made the map wrote down, which is usually the street names, towns, and major interesting areas. Of course, you have no way to know whether that information is right, and more importantly, you don't actually see what's on the ground there. Back a few decades ago, spy agencies needed something better to monitor enemy movement, and that's where live satellite images started.
It used to be that only the most trained, top secret personnel could handle satellite images. They were trained in aerial photo interpretation, and could look at images of the Earth taken from planes or satellites, and figure out what went on the ground. They could see roads, trees, buildings, vehicles, even people, not as they were years ago when a map was created, but very recently, almost live, when the picture was snapped. It modernized warfare, and allowed vast advances to be made.
Now of course, everyone has access to these aerial photographs, and you don't need to know what reading topographic maps means to interpret them. Whether you go to Google Maps and turn on satellite view, or if you use a more live system as part of a job or security contract, the quality of photos and the familiarity all of us have with these types of top-down views of the planet enable everyone to quickly understand what goes on in the images. More than that, many services such as Google and Microsoft maps now offer multiple layers using dynamic HTML techniques, which allows us to view a layer with known routes and place names on top of the satellite image.
Another application for live images is by scientists. Some of them watch for raising tides, or potential hazardous areas of the world. Others watch volcanoes, and using infra-red lenses on high altitude planes, photos can be taken to view things that normally cannot be seen with the naked eye. There's even cameras made especially for taking images of the bottom of the sea, going through the water and mapping the relief thousands of feet deep.
Live satellite images really transformed our lives, from the initial use in military applications, to business uses such as to be able to line up roads and construction sites, and even entertainment, when you go online and watch the Egypt pyramids from up top. With the increasing amount of planes and satellites doing this work, the images are updated more and more often, and soon all of us will have access to real time views of the Earth from our couch. Who knows, maybe you could even go outside, and see yourself on the ground, as you walk up, like in spy films.