Hyperspectral imaging is an advanced imaging technique that measures visible and near-infrared light reflecting off the Earth’s surface. Researchers use hyperspectral imaging spectrometer data to identify and characterize mineral deposits, vegetation, and other land surface features.
In 2007, USGS scientists acquired airborne hyperspectral data for most of Afghanistan as part of the USGS Oil and Natural Gas Project assessment of earthquake hazards and natural resources, including coal, water, and mineral deposits. The team used the HyMap imaging spectrometer, which measures 128 channels of reflected sunlight at wavelengths between 0.4 and 2.5 microns, to collect over 200 flight lines worth of data that covered 438,012 square kilometers of the Afghan landscape. The resulting dataset includes more than 800,000,000 pixels of hyperspectral data.
Once processed, these HyMap data were used to create unique and detailed maps of different surface materials. For example, Hyperspectral Data Project staff used the data to better define the magnitude and extent of mineral deposits within 21 Areas of Interest (AOI) in Afghanistan, selected in collaboration with the Department of Defense Task Force for Business and Stability Operations (TFBSO) on the basis of their documented potential for rapid economic development; see the 2011 report, Identification of Mineral Resources in Afghanistan—Detecting and Mapping Resource Anomalies in Prioritized Areas Using Geophysical and Remote Sensing (ASTER and HyMap) Data. Project staff also used HyMap data to generate the hyperspectral mapping analysis figures included in the 2011 USGS Minerals Project report, Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan. High-resolution versions of these figures are available for download here.
In July 2012, the Hyperspectral Data team released two surface materials maps of Afghanistan that were created using the HyMap data and produced in partnership with the Afghan Geological Survey and TFBSO. One of the maps shows the spatial distribution of carbonates, phyllosilicates, sulfates, altered minerals, and other materials with diagnostic absorption features in the shortwave infrared wavelengths. The second map shows the spatial distribution of iron-bearing minerals and other materials with diagnostic absorptions at visible and near-infrared wavelengths. These maps represent a milestone in the use of hyperspectral imaging data, as Afghanistan is the first country to be almost completely mapped using HyMap technology. Both maps are available as free downloads (see below).
The hyperspectral surface materials maps were subset from the whole country to a quadrangle map series. These are the most recent addition to a series of U.S. Geological Survey/Afghanistan Geological Survey 1:250,000-scale quadrangle maps covering Afghanistan.
The hyperspectral surface materials maps of Afghanistan are available here .
For the new hyperspectral surface materials 1:250,000-scale quadrangle series, go here.
Access the Identification of Mineral Resources in Afghanistan report here.
A list of all USGS Hyperspectral Data Project publications can be found here.