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Posts Tagged ‘NASA’

Imaging Spectrometer data from NASA AVIRIS

June 11, 2018 1 comment

The NASA AVIRIS mission has generated imaging spectrometer data for many areas of the USA since the 1990s.  The AVIRIS download portal for data from 2006 onward is on a node at NASA, here.  The AVIRIS sensor collects data that can be used for characterization of the Earth’s surface and atmosphere from geometrically coherent spectroradiometric measurements. This data can be applied to studies in the fields of oceanography, environmental science, snow hydrology, geology, volcanology, soil and land management, atmospheric and aerosol studies, agriculture, and limnology.  Applications under development include the assessment and monitoring of environmental hazards such as toxic waste, oil spills, and land/air/water pollution. With proper calibration and correction for atmospheric effects, the measurements can be converted to ground reflectance data which can then be used for quantitative characterization of surface features. In short, AVIRIS can collect in over 200 bands and therefore it can help analysts work out details such as vegetation health, or even species type, from the data.

The AVIRIS portal, presented in a Google map with popups with download links, as well as the  metadata file (in plain text format, available here)  both look very dated.  But this is a case where we encourage the user to give it a try–the portal may not look modern, but the data behind the portal is incredibly useful.   One can toggle data layers in the right hand corner of map to show All AVIRIS data or the Attrib. Filtered data (data that meets the attribute criteria but ignores the spatial filter).  One can also bound a box on the map, which has long been a favorite feature of mine on data portals, using the red rectangle to activate.  To update the spatial filter, click the “Update Map” button below the map.   The files are not streamed, but must be downloaded; perhaps because of their large size (typically over 1 GB).  Again, think “old school” formats – zip files and TAR files, but again, the data are plentiful and useful.   A set of previews are available, for example, here, and shown below.  For more information about AVIRIS data, see this link and this link.

aviris

 

The AVIRIS data portal.

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A sample AVIRIS image. 

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NASA’s New Data Portal

May 25, 2015 1 comment

NASA recently announced the launch of a new data portal, hosting a data catalog of publicly available terrestrial and space-based datasets, APIs and data visualisations.

NASA Data Portal

NASA Data Portal

NASA’s Open Innovation team has been established to meet government mandates to make their data publicly available. The datasets, posted in a number of categories including applied and earth science, will be available to download in a variety of formats although at present not all the formats are available for all of the categories. However the data portal is work in progress so worth checking back as new datasets are posted.

From a quick search for some earth science data I found a sea surface temperature dataset acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments aboard NASA’s Terra and Aqua satellites that I could download in a number of image formats, Google Earth or CSV format. One feature of the data portal I found useful was the accompanying basic, intermediate or advanced dataset descriptions, helping portal users identify the right datasets for their requirements.

MODIS Sea Surface Temperature dataset

MODIS Sea Surface Temperature dataset