Todd Hoefen
Science and Products
Spectroscopy and Hyperspectral Imaging of Critical Mineral Resources
Our project will characterize the primary critical minerals (minerals that contain critical elements in their base structure) that are not yet in the USGS Spectral Library. We propose to increase understanding of the spectral indicators of critical minerals using lab-based studies of hand specimens and drill core, hyperspectral field...
Development and Validation of Hyperspectral Imager for Field and Lab Scanning
The Mineral Resources Program has advanced methods of imaging spectroscopy (hyperspectral remote sensing) that are now used routinely by the earth science and remote sensing communities for mineral mapping, soil quality mapping, hazard mitigation, and other terrestrial and planetary applications. The USGS is highly qualified to advance this technology based on its world class expertise in...
USGS High Resolution Spectral Library
The USGS Spectral Library contains reflectance spectra, including samples of minerals, rocks, soils, physically constructed as well as mathematically computed mixtures, plants, vegetation communities, microorganisms, and man-made materials. The samples and spectra collected were assembled for the purpose of using spectral features for the remote detection of these and similar materials. The...
Hyperspectral Surface Materials Maps of Afghanistan 1:250,000-scale Quadrangle Series
1:250,000-scale quadrangle maps covering Afghanistan showing the distribution of iron-bearing minerals, selected carbonates, phyllosilicates, sulfates, altered minerals, and other materials derived from analysis of HyMap imaging spectrometer data.
Interactive USGS Spectral Library Version 7
Interactive website allowing users to search the contents of the USGS Spectral Library Version 7 data.
USGS Digital Spectral Library
References for material identification in remote sensing images. The library contains spectral reflectance data for of hundreds of materials, including minerals, vegetation, organic and volatile compounds, and man-made materials.
Imaging spectroscopy for the detection, assessment and monitoring of natural and anthropogenic hazards
Natural and anthropogenic hazards have the potential to impact all aspects of society including its economy and the environment. Diagnostic data to inform decision-making are critical for hazard management whether for emergency response, routine monitoring or assessments of potential risks. Imaging spectroscopy (IS) has unique contributions to...
Ong, Cindy; Carrere, Véronique; Chabrillat, Sabine; Clark, Roger N.; Hoefen, Todd M.; Kokaly, Raymond; Marion, Rodolphe; Souza Filho, Carlos Roberto de; Swayze, Gregg A.; Thompson, David R. Characterizing the source of potentially asbestos-bearing commercial vermiculite insulation using in situ IR spectroscopy
Commercially produced vermiculite insulation from Libby, Montana, contains trace levels of asbestiform amphibole, which is known to cause asbestos-related diseases. When vermiculite insulation is found in a building, evaluation for its potential asbestos content traditionally involves collecting a sample from an attic or wall and submitting it for...
Swayze, Gregg A.; Lowers, Heather A.; Benzel, William M.; Clark, Roger N.; Driscoll, Rhonda L.; Perlman, Zac S.; Hoefen, Todd M.; Dyar, M. Darby Multiscale hyperspectral imaging of the Orange Hill Porphyry Copper Deposit, Alaska, USA, with laboratory-, field-, and aircraft-based imaging spectrometers
In the past decade, use of hyperspectral imaging (imaging spectroscopy) for mineral exploration and mining operations has been increasing at different spatial scales. In this paper, we focus on recent trends in applying imaging spectrometer data to: 1) airborne imaging of high latitude deposits, 2) field-based imaging of outcrops, and 3)...
Kokaly, Raymond; Graham, Garth E.; Hoefen, Todd M.; Kelley, Karen D.; Johnson, Michaela R.; Hubbard, Bernard E.; Buchhorn, M.; Prakash, A.
USGS Spectral Library Version 7
We have assembled a library of spectra measured with laboratory, field, and airborne spectrometers. The instruments used cover wavelengths from the ultraviolet to the far infrared (0.2 to 200 microns [μm]). Laboratory samples of specific minerals, plants, chemical compounds, and manmade materials were measured. In many cases, samples were purified...
Kokaly, Raymond F.; Clark, Roger N.; Swayze, Gregg A.; Livo, K. Eric; Hoefen, Todd M.; Pearson, Neil C.; Wise, Richard A.; Benzel, William M.; Lowers, Heather A.; Driscoll, Rhonda L.; Klein, Anna J. Environmental implications of the use of sulfidic back-bay sediments for dune reconstruction — Lessons learned post Hurricane Sandy
Some barrier-island dunes damaged or destroyed by Hurricane Sandy's storm surges in October 2012 have been reconstructed using sediments dredged from back bays. These sand-, clay-, and iron sulfide-rich sediments were used to make berm-like cores for the reconstructed dunes, which were then covered by beach sand. In November 2013, we sampled and...
Plumlee, Geoffrey S.; Benzel, William M.; Hoefen, Todd M.; Hageman, Philip L.; Morman, Suzette A.; Reilly, Timothy J.; Adams, Monique; Berry, Cyrus J.; Fischer, Jeffrey; Fisher, Irene
Hyperspectral surveying for mineral resources in Alaska
Alaska is a major producer of base and precious metals and has a high potential for additional undiscovered mineral resources. However, discovery is hindered by Alaska’s vast size, remoteness, and rugged terrain. New methods are needed to overcome these obstacles in order to fully evaluate Alaska’s geology and mineral resource...
Kokaly, Raymond F.; Graham, Garth E.; Hoefen, Todd M.; Kelley, Karen D.; Johnson, Michaela R.; Hubbard, Bernard E. Trace elements in stormflow, ash, and burned soil following the 2009 station fire in southern California
Most research on the effects of wildfires on stream water quality has focused on suspended sediment and nutrients in streams and water bodies, and relatively little research has examined the effects of wildfires on trace elements. The purpose of this study was two-fold: 1) to determine the effect of the 2009 Station Fire in the Angeles National...
Burton, Carmen A.; Hoefen, Todd M.; Plumlee, Geoffrey S.; Baumberger, Katherine L.; Backlin, Adam R.; Gallegos, Elizabeth; Fisher, Robert N. Mapping surficial minerals at high latitudes: The USGS 2014 imaging spectrometer data collection in Alaska
Passive optical remote sensing of high latitude regions faces many challenges including a short acquisition season and poor illumination due to low solar elevation. Additional complications are encountered in the identification of surface minerals for mineral resource characterization because minerals of interest commonly are exposed on steep...
Kokaly, Raymond F.; Hoefen, Todd M.; Graham, Garth; Kelly, Karen; Johnson, Michaela; Hubbard, Bernard; Goldfarb, Richard The environmental and medical geochemistry of potentially hazardous materials produced by disasters
Many natural or human-caused disasters release potentially hazardous materials (HM) that may pose threats to the environment and health of exposed humans, wildlife, and livestock. This chapter summarizes the environmentally and toxicologically significant physical, mineralogical, and geochemical characteristics of materials produced by a wide...
Plumlee, Geoffrey S.; Morman, Suzette A.; Meeker, G.P.; Hoefen, Todd M.; Hageman, Philip L.; Wolf, Ruth E.
Deposit model for heavy-mineral sands in coastal environments
This report provides a descriptive model of heavy-mineral sands, which are sedimentary deposits of dense minerals that accumulate with sand, silt, and clay in coastal environments, locally forming economic concentrations of the heavy minerals. This deposit type is the main source of titanium feedstock for the titanium dioxide (TiO2) pigments...
Van Gosen, Bradley S.; Fey, David L.; Shah, Anjana K.; Verplanck, Philip L.; Hoefen, Todd M. Asphaltene content and composition as a measure of Deepwater Horizon oil spill losses within the first 80 days
The composition and content of asphaltenes in spilled and original wellhead oils from the Deepwater Horizon (DWH) incident provide information on the amount of original oil lost and the processes most responsible for the losses within the first 80 days of the active spill. Spilled oils were collected from open waters, coastal waters and coastal...
Lewan, M.D.; Warden, A.; Dias, R.F.; Lowry, Z.K.; Hannah, T.L.; Lillis, P.G.; Kokaly, R.F.; Hoefen, T.M.; Swayze, G.A.; Mills, C.T.; Harris, S.H.; Plumlee, G.S.
Hyperspectral Surface Materials Map of Quadrangle 3268, Khayr Kot (521) and Urgun (522) Quadrangles, Afghanistan, Showing Iron-bearing Minerals and Other Materials
This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at...
King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Giles, Stuart A.; Johnson, Michaela R.
Prescribed Burn — Tall Timbers Research Station, FL (Footage of Drone)
See the actual drone footage at: https://www.usgs.gov/media/videos/prescribed-burn-tall-timbers-research-...
Footage of drone during a prescribed fire at Tall Timbers Research Station, Tallahassee, Florida (April 19, 2017).
Prescribed Burn — Tall Timbers Research Station, FL (Drone)
Drone footage of a prescribed fire at Tall Timbers Research Station, Tallahassee, Florida (April 19, 2017).
DJI S1000 UAS with a “Kolibri” Sensor
DJI S1000 UAS with a “Kolibri” sensor that measures carbon dioxide and monoxide, particulate matter, black carbon, and brown carbon. In addition, the UAS is equipped with a high-resolution video camera and a forward-looking thermal IR Micro-Epsilon TIM 400 camera.
Very High-Resolution Thermal Infrared Image, Fire Line Temperature
A single very high-resolution thermal infrared image shows the temperature of the fire line. When used with a time series of images, rate of flame spread, fire intensity and temperature can be calculated. Temperature gradient in Celsius (C) to the right and denotes 150 C (black/purple), 415 C (red/orange) and 680 C (yellow/off-white).
Prescribed Burn at Tall Timbers Research Station
Prescribed burn at Tall Timbers Research Station, Pebble Hill location Block B/Unit C2 (4-year rough).
DJI S1000 UAS Flying into Smoke Plume
DJI S1000 UAS flying into smoke plume at Pebble Hill location Block B/Unit C2, Tall Timbers Research Station.
Spectral Signature of Plywood
This shows the spectral signature (left) of plywood (right).
Spectral Signature of Topaz
This shows the spectral signature (left) of the mineral topaz (right).
Igniting a New Trend in Public Safety
U.S. Geological Survey scientists and partners are taking technology to the next level, using unmanned aircraft systems (UAS), commonly called drones, to acquire both fire intensity and emissions data during prescribed burns.
USGS Spectral Library gets Ultra- and Hyper- Revamp
We've got a library full of spectral signatures, like a police fingerprint library for minerals and other substances!