US relases secret data
High resolution radar data maps of Europe, North America and other key parts of the world captured on a space shuttle mission 14 years ago have been made public for the first time this month.
Former Nasa astronaut Kathy Sullivan, now head of the US National Oceanic and Atmospheric Administration (NOAA), welcomed the release of previously secret data. “The declassification of 30 metre elevation data represents a vast improvement over the previous freely available data set which resolved to just 90 m,” she says.
This second tranche of high resolution data to be released under the direction of President Obama follows on from highly accurate terrain maps of Africa which became available in October.
Nasa’s ground-breaking Shuttle Radar Topographic Mission (SRTM) recorded digital elevation data (DEMs) in February 2000 for over 80 per cent of the globe – but until now only a 90 m resolution version was released.
The 30 m resolution data was kept secret for use by the US military and intelligence agencies – but even the 90 m resolution data revealed for the first time detailed swaths of the planet’s topography previously obscured by persistent cloudiness.
Dr Sullivan says aid organisations, development banks and decision-makers in developing countries will be able to better map and plan for climate-driven challenges.
SRTM mission project scientist at the Jet Propulsion Laboratory (JPL), Michael Kobrick, added: “SRTM was among the most significant science missions the shuttle ever performed and was probably the most significant mapping mission of any single type ever.”
It consisted of a specially modified radar system comprising two radar antennas – one located in the shuttle’s payload bay, the other on the end of a 60 m mast extending into space.
The surface of Earth was mapped numerous times from different perspectives and the combined radar data processed at JPL in California to produce a series of global topographic maps.
Topography influences key natural processes, such as the distribution of plant communities and the associated animals that depend upon them, weather and rainfall patterns, and the flow and storage of surface water.
The digital elevation maps benefit many activities, from aviation safety to civil engineering projects, and the data is helpful in predicting and responding to flooding from severe storms and the threats of coastal inundation associated with storm surges, tsunamis and rising sea-levels.
For a full version of this article by Clive Simpson click here – Taking our planet’s pulse