Land Use and Land Change
How is land being used, and how is it changing? It is now possible to observe land changes by satellite with more precision than ever before.
A clear picture of land changes
In 2010, the new D Runway was completed at Haneda Airport. These three pictures show the process up to completion. They illustrate the way in which ALOS has covered the entire planet to record changes in land over time at a resolution of 2.5 m.
Previously, satellite imagery was imprecise due to inaccurate information about the location of each satellite, so matching data to a map was a difficult challenge. However, ALOS has used tremendous progress in GPS technology to overcome this problem. ALOS imagery now maps perfectly to existing schema within a 5 m margin of error. This imagery is available for the entire planet and is ready to use. Another strength of ALOS data is that with analysis, information about topography and surface areas can also be extracted.
Using this as a base map, in conjunction with analyses of other satellite imagery and data, can expand the possibilities for extracting useful information of various kinds on land in every region moving forward.
The latest data from currently operational satellites
ALOS, which launched in January 2006, was decommissioned in May 2011 having outlived its three-year design lifespan and five-year target lifespan. ALOS data is therefore available only from this period, but its successor, the ALOS-2, is scheduled for launch in FY2013, and it is expected to resume the flow of the equivalent data.
Moreover, it can also be used in combination with data from other currently operational satellites. Most prominent of these are the US LANDSAT, Thailand’s THEOS, commercial satellite, World View-1, 2 and Quick Bird which run optical sensors, and the Synthetic Aperture Radar-mounted Canadian RADARSAT-2 and German TerraSAR-X. If each of their strengths can be harnessed, the possibilities for satellite data expand further still.