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Posts Tagged ‘satellite’

Copernicus Earth Observation Programme – Data and Information Access Services (DIAS)

August 13, 2019 1 comment

To facilitate access to the European Space Agency’s (ESA) Copernicus earth observation data (Sentinel satellites), the European Commission has funded five cloud-based platforms, known as the Data and Information Access Services (DIAS), to provide users with easy access to data from the various satellite missions. The data are available on the platforms, subject to account registration, as both open data and on a pay-per-use basis.

The following examples of data search and download options were taken from the WEkEO data service. The other data hosting services include ONDA, numdi, sobloo  and CREODIAS.

The raw data are available as NetCDF (.nc) files on the WEkEO site, an example of which is shown here using the Panoply data viewer.

There are various tools available to convert NetCDF files to more GIS friendly formats such as the Marine Geospatial Ecology Tools, a free add-on for ArcGIS that converts NetCDF to ASCII and ArcGrid formats.

 

 

 

Categories: Public Domain Data Tags: , ,

Sentinel-2 Imagery Now Available

December 14, 2015 1 comment

Earlier this year we wrote about the launch of the European Space Agency’s (ESA) Sentinel-2A satellite and the mission to deliver a range of data products including land cover maps and bio-geophysical data. ESA have just released the Sentinel-2A orthorectified products, which are now available to download for free from the Sentinel-2 Data Hub https://scihub.copernicus.eu/s2/.

Sentinel-2a Data Hub

Sentinel-2a Data Hub

ESA have also posted a data quality report to document the current status of the data and provide information on product formats and features. As the programme is currently in a ramp-up phase, further improvements in the extent of coverage and the accuracy of the products are expected over the next few months.

2015 and Beyond: Who will control the data?

November 17, 2015 1 comment

Earlier this year Michael F. Goodchild, Emeritus Professor of Geography at the University of California at Santa Barbara, shared some thoughts about current and future GIS-related developments in an article for ArcWatch. It was interesting to note the importance attached to the issues of privacy and the volume of personal information that is now routinely captured through our browsing habits and online activities.

Prof. Goodchild sees the privacy issue as essentially one of control; what control do we as individuals have over the data that are captured about us and how that data are used. For some the solution may be to create their own personal data stores and retreat from public forums on the Internet. For others, an increasing appreciation of the value of personal information to governments and corporations, may offer a way to reclaim some control over their data. The data could be sold or traded for access to services, a trend we also commented on in a previous post.

Turning next to big data, the associated issues were characterised as the three Vs:

  • Volume—Capture, management and analysis of unprecedented volumes of data
  • Variety—Multiple data sources to locate, access, search and retrieve data from
  • Velocity—Real-time or near real-time monitoring and data collection

Together the three Vs bring a new set of challenges for data analysts and new tools and techniques will be required to process and analyse the data. These tools will be required to not only better illustrate the patterns of current behaviour but to predict more accurately future events, such as extreme weather and the outbreak and the spread of infectious diseases, and socio-economic trends. In a recent post on GIS Lounge Zachary Romano described one such initiative from Orbital Insights,  a ‘geospatial big data’ company based in California. The company is developing deep learning processes that will recognise patterns of human behaviour in satellite imagery and cited the examples of the number of cars in a car park as an indicator of retail sales or the presence of shadows as an indicator of construction activity. As the author noted, ‘Applications of this analytical tool are theoretically endless‘.

Will these new tools use satellite imagery to track changes at the level of individual properties? Assuming potentially yes, the issue of control over personal data comes to the fore again, only this time most of us won’t know what satellites are watching us, which organisations or governments control those satellites and who is doing what with our data.

 

Sentinel-2A: ESA’s latest satellite launched

July 6, 2015 1 comment

The European Space Agency (ESA) recently launched their latest environmental monitoring satellite, Sentinel-2A, adding high-resolution optical imaging capability to the radar imagery provided by the first satellite in the Copernicus fleet, Sentinel-1A. Tasked with combining wide swaths and short revisit times (5-day cycle), Sentinel-2A will monitor land and vegetation change to deliver a range of data products including land cover maps and indices for a number bio-geophysical variables. Although the commissioning phase will last for about three months, Sentinel-2A has already recorded its first images.

Sentinel-2A's first image: Po Valley - NW Italy/Sth France. 27 June 2015

Sentinel-2A’s first image: Po Valley – NW Italy/Sth France. 27 June 2015

Once operational, Sentinel-2A’s imagery will be hosted on the Sentinels Scientific Data Hub, which will be upgraded shortly to accommodate the new satellite. The data will be available on a ‘free and open’ basis to any users registered with the data hub. Although the data will be made publicly available, they will not be in the public domain and remain the intellectual property of Copernicus Programme. However, subject to the ESA’s terms and conditions, users are free to user, alter, modify, publish and distribute the data. Judging by the first data samples, Sentinel-2A’s imagery will provide an invaluable resource for global environmental monitoring.

 

 

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.

 

 

 

 

 

Sentinel-1A Satellite: Transforming the analysis of earthquake data

September 8, 2014 1 comment

We’ve previously written about the launch and progress of the Sentinal-1A satellite, part of the European Union’s Copernicus earth observation project. Although still being commissioned and not yet in full production mode, the satellite recently provided radar imagery from Northern California captured before and after the Napa Valley earthquake on 24 August.

Using a technique known as ‘Synthetic aperture radar interferometry’, two images of the same area were compared to identify areas of significant change. Changes to the ground surface modify the reflected radar signal detected by the satellite, and those modified signals can be plotted as an ‘interferogram’ (Source: Radar vision maps Napa Valley earthquake.) The result is both colourful and striking; the fault responsible for the 6.0 earthquake was confirmed as the West Napa Fault, and both the scale and the extent of the surface rupture was immediately apparent.

Napa Valley Quake interferogram

Napa Valley Quaket: © Copernicus data (2014)/ESA/PPO.labs/Norut/COMET-SEOM Insarap study

Imagery like these examples captured for the Napa Valley quake looks set to transform how scientists and data analysts map and respond to earthquakes. With the launch of second Sentinel satellite (1B) in 2016, the imagery update cycle will be reduced from 12 to 6 days. The timely and open publication of high resolution data to support activities on the ground and post quake analysis after each event, should provide unprecedented monitoring of the Earth’s surface.

 

Update on the Sentinel-1A satellite

June 16, 2014 2 comments

In April we wrote about the launch of the Sentinel-1A satellite, part of the European Union’s Copernicus Earth Observation project, and the plans to make the data publicly available. Although the satellite is still being calibrated and not yet fully operational, it has already provided some radar data to help support the recent flood mapping activity in the Balkans. As the radar on-board Sentinal-1A can operate through cloud, rain and in darkness it is especially useful for monitoring floods.

After persistent heavy rainfall resulted in widespread flooding and a number of landslides in Bosnia and Herzegovina, the emergency services needed access to accurate and current maps of the region to support the relief effort.  The data from Sentinel-1A helped identify areas of flooding that the emergency services were unaware of.

Balkan Flood Map.  © ESA/European Commission

Balkan Flood Map.
© ESA/European Commission

 

The Sentinel-1A satellite has also helped monitor flooding when the Zambezi River burst its banks in April, inundating the border between Namibia, Zambia and Botswana. Data from the satellite were made available to the Namibian authorities within three hours of collection, providing near real-time information for an area had been difficult to survey on the ground.

Given the impact Sentinel-1A has already had, the Earth Observation project looks set to make a major contribution to environmental monitoring and assessment. The satellite will soon be fully operational, helping to provide some of the data that will support a more holistic approach to environmental management.