ENVI Plays Key Role in Oil Seep Detection
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Customer Challenge
Asset monitoring is critical for energy and oil companies. Because assets can be difficult to map and assess on a regular basis, decisions regarding their development and maintenance are made with limited and often inaccurate data. Ellis GeoSpatial of Walnut Creek, California needed a way to help energy and oil companies better monitor their valuable resources.
Solution Achieved
Ellis GeoSpatial developed a method for asset monitoring by creating detailed environmental baselines and maps of oil fields, refineries, tank farms, pipelines and exploration acreage. By accurately and thoroughly mapping areas to identify soil that has been impacted by oil seeps, oil companies can locate potentially rich oil reserves hidden beneath the Earth’s surface for exploration purposes, or can prevent environmental damage by controlling seepage resulting from an oil spill. By using environmental data from a variety of imaging sensors to assess vegetation types, vegetation stress, soil conditions, land use/land cover, infrastructure and water conditions, Ellis GeoSpatial can create effective environmental baselines for its customers. The use of ENVI® for visualizing and analyzing hyperspectral satellite imagery is a critical tool in this process.
The Versatility of ENVI for Geologic Mapping
As the tool of choice for the processing and analysis of the hyperspectral data, ENVI plays a key role in the development of environmental baselines. Steve Ellis of Ellis GeoSpatial selected ENVI based on a number of important factors. “ENVI supports multiple data sources for engineering and geologic applications, which is obviously critical for our services because we’re using so many different kinds of data. It also supports different methods for analyzing hyperspectral imagery and features a variety of sophisticated algorithms that allow us to create more focused maps and integrate seamlessly with geographic information systems,” Ellis explains.
To create an environmental baseline, Ellis and his team use a combination of hyperspectral imagery, other image data, basemaps, and field data integrated into a geographic information system (GIS). They rapidly develop natural color, color-infrared, and full-infrared composites using ENVI to help familiarize the analyst with the terrain, environment, geomorphology and man-made infrastructure. ENVI's visualization and analysis tools are then used to locate and spectrally characterize oil seeps and oil-impacted soils. One of the products developed with ENVI are a series of black and white raster images that contain the features of interest—such as oil-impacted surfaces, vegetation types, iron minerals and carbonates. Then, the team applies a rectification transformation to each image to warp it into a specified map projection and datum. The quality of the rectification often determines the usefulness of the hyperspectral color composites and derived maps for the exploration client.
ENVI's versatility enables Ellis’ team to quickly process hyperspectral imagery for multiple geologic and land analysis applications, including mapping of soils, plant communities, paved surfaces, vegetation vigor and land use/land cover. A number of routines support functions specifically related to using hyperspectral data, especially the ability to extract information at the sub-pixel level.
"ENVI's subpixel and unmixing algorithms enable us to detect small amounts of hydrocarbon-based material that occur within each pixel,” said Ellis. “This is a key capability in working with hyperspectral data."
The use of ENVI for mapping targets that have unique and strong spectral signatures, such as the clay minerals associated with hydrothermal alteration, is valuable for creating spectral libraries. ENVI's unique algorithms are used for spectral compression to reduce data size and accelerate the analysis process, making the number of spectral bands easier to manipulate.
Key Benefits
- ENVI's versatility enables Ellis’ team to quickly process hyperspectral imagery for multiple geologic and land analysis applications.
- ENVI is reliable, well documented, and very flexible, and enables them to create sophisticated products and meet clients expectations and deadlines.
- ENVI supports multiple data sources for engineering and geologic applications. It also supports different methods for analyzing hyperspectral imagery and features a variety of sophisticated algorithms to create more focused maps and integrate seamlessly with geographic information systems.