Updating land cover maps satellite images
At the time, Google used shots captured by the less-capable Landsat 7, which suffered a hardware failure back in 2003 that resulted in some portions of the world having diagonal gaps of missing data.Below, you can see the how Landsat 8's imagery of New York City is vast improvement over what Google was using before: Google says its new mosaic was crafted from nearly a petabyte of data containing more than 700 trillion pixels.The company is able to make use of this imagery because NASA, in collaboration with the United States Geological Survey makes its Landsat database open source for anyone to make use of.All the imagery can be accessed using the Earth Engine application programming interface, which scientists use to study large-scale global changes in the environment and track the spread of diseases.
A set of recent images with acceptable levels of cloud cover was identified and obtained from the relevant archives for the Area of Interest (AOI).
You can't find out when a map was last updated on Google Maps.
However, you can find this data by downloading Google Earth and searching for the location in that program.
With Google's Follow Your World tool, you can also sign up for email notifications when specific location images change.
The satellite data on Google Maps is typically between 1 to 3 years old.In Google's case, the imagery is used for a simpler purpose.Still, it's endlessly fascinating to scour the globe from the distance of an orbiting satellite, and the view has never looked better.By stitching together selective portions of the Earth with clear skies, Google's mosaic is able to eliminate clouds and other weather obstructions to create a crystal-clear snapshot of every corner of the world.