Landsat imagery is essential for studying land use change over time. Esri’s Peter Becker explained how the Esri Landsat imagery service showed changes in Dubai, UAE, from the sleepy village in 1975, to the mega-modern metropolis of 2012. Vinay Viswambharan demonstrated ArcGIS imagery tools that analyze data at the neighborhood level.
Peter is asked to show how much Dubai has changed in 40 years. Using the Landsat imagery service, Peter shows change over time in Dubai. Using an area of interest tool, the Landsat imagery service creates image classifications showing changes. In 1975, the small coastal town of Dubai became a city. 1990 imagery shows an airport and runway expansion; 2000 imagery shows vegetation; 2005 imagery shows palm-shaped islands in the gulf; and 2010 imagery shows further developments along the coast.
Landsat imagery services are available for you to use today. Go to ArcGIS Online and search for “Landsat Service.” You can use your desktop computer to access those services and bring them directly into ArcGIS for Desktop. The ArcGIS Landsat service enables you to perform dynamic analysis from your server database. You can now perform a dynamic classification of data so you can create a land\water interface, or define landuse classes (sea, sand, urban vegetation.) Landsat imagery services can be used by geoprocessing tools for analyzing properties, extracting statistics, and displaying results. The results can be published on the ArcGIS Online platform and added to a web application.
In his demo, Vinay Viswambharan uses ArcGIS imagery tools to show urban change and create plans for urban development. He has raw Landsat imagery on disc. ArcGIS leverages metadata and brings it into the product. Using the ArcGIS 10.1 georeferencing toolbar, he aligns historical imagery. The tool computes tie points and automatically adjusts the imagery to match. Another image tool defines and performs image orthorectification on the fly.
Vinay measures a tall building by using shadow-based measurements. He uses another tool to process a mosaic dataset on the fly. The Landsat imagery service manages and serves massive datasets. Vinay turns on the mosaic data and studies UAE changes by bringing together 2,500 landsat image scenes that contain a total of 2.5 terabytes of data. He processes these images on the fly. In a brilliant 3D representation, Vinay shows a 3D image of Dubai at night. He posts this product on ArcGIS Online.
Esri Landsat imagery services can be used on a mobile device from the ArcGIS Online service for free. Users can use these services to author web applications and share imagery and products.