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Archive for October, 2014

First WorldView-3 high resolution images now available

October 20, 2014 1 comment

The first imagery from DigitalGlobe’s WorldView-3 satellite, launched in early August  2014, has already been received and although still in the testing and calibration phase, the imagery has been lauded a new standard in resolution (maximum 31 cm) and clarity. Despite the fact that the imagery was taken from an altitude of approximately 620 km, the images provide a level of detail and image sharpness that were previously only available from aerial photography.

Samples of the data are available on the DigitalGlobe and Mapbox.com sites and include imagery from Barcelona and Madrid in Spain. From the airport imagery it’s possible to identify individual planes, runway markings and other detailed airport infrastructure.

WorldView-3 Imagery

© DigitalGlobe

In addition to the improved resolution, WorldView-3 incorporates additional spectral bands (29 in total) to sense previously undetected changes in vegetation, variations in surface composition, moisture levels and building materials.

 

 

 

 

 

High-resolution SRTM elevation data to be released globally

October 12, 2014 1 comment
Comparing SRTM data resolutions

Comparing SRTM data spatial resolution:  90 meters on the left, 30 meters on the right.

High-resolution elevation data from the Shuttle Radar Topography Mission-Level 2 (SRTM-2), previously only available for the USA, will be made publicly available over the next 12 months, the White House announced recently at the United Nations Heads of State Climate Summit. The first elevation data set to be released will be over the African continent and is available on the United States Geological Survey’s Earth Explorer website, by choosing the “SRTM 1 Arc-Second Global” data set, with future regions to be released within the coming year.

“I look forward to the broader impact that the release will have on the global scientific and capacity building community,” said National Geospatial-Intelligence Agency (NGA) Director Letitia Long.  Until now, SRTM data was only publicly available at a lower 90-meter resolution (see above image). The newly-released global 30-meter SRTM-2 dataset will be used worldwide to improve environmental monitoring, climate change research including sea-level rise impact assessments, and local decision support, the White House said.

The SRTM mission began in 2000 as a venture between NASA and NGA that used a modified radar system on board the Space Shuttle Endeavour to acquire elevation data for over 80% of the Earth’s land mass. The Department of Defense and intelligence community continues to use this topographic data for multiple applications – from developing navigation tools and supporting military operations, to geological and environmental purposes.  In August 2014, Long authorized the removal of the Limited Distribution caveat from the SRTM-2 dataset, making it available to the public on a phased-release schedule. The 30-meter topographic dataset was then sent to USGS for public distribution.

When I heard Shuttle pilot Dom Gorie speak about his work with the SRTM at a GIS conference about 10 years ago, it was one of the most memorable keynote addresses I have ever heard.  I look forward to investigating this new data set and the delivery mechanism.  Keep an eye on this blog for further updates.

 

Mapping forgotten places

October 6, 2014 2 comments

Reported in the Guardian newspaper today are plans to map the world’s forgotten places. As the report discusses a surprisingly large number of the world’s cities in some of the poorest countries are unmapped. While local agencies can muddle along using photocopies or out of date and low resolution aerial images for day to day activities, the problems associated with the lack of accurate and current maps are exacerbated during times of conflict or natural disaster. Without access to reliable digital maps, local emergency response teams and humanitarian agencies often lack the necessary spatial data, such as accurate road network information, that they rely on to provide aid and help reconstruct local communities.

One solution to the problem is the soon to be launched Missing Maps Project, a collaborative project involving among others Médecins Sans Frontières, the American and British Red Cross, the Humanitarian OpenStreetMap. The plan is quite simple – create digital maps for every settlement on Earth as part of what is described as ‘ nothing less than a human genome project for the world’s cities‘. Building on the volunteer crowd sourcing data capture techniques developed by OpenStreetMap, the project will make satellite imagery available via the OpenStreetMap mapping interface.

Tracing building outlines in OpenStreetMap

Tracing building outlines in OpenStreetMap

Volunteers can then log in from anywhere in the world and start digitising road and river networks, building outlines and other infrastructure, in effect creating basic but current digital maps of the cities. Local volunteers then add street and building names and the completed maps are posted back to the Missing Maps head office in London. With end-to-end crowd sourcing and the probably largest team of volunteer mappers ever mobilised, the project aims to map the world’s poorest urban areas within two years and provide a global open access and open source dataset to support local communities.