Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Skip to content

Mineral predominance map for Nabesna, Alaska, derived from imaging spectrometer reflectance data

Metadata Updated: July 6, 2024

Reflectance data from HyMap™ were processed using the Material Identification and Characterization Algorithm (MICA), a module of the USGS PRISM (Processing Routines in IDL for Spectroscopic Measurements) software (Kokaly, 2011), programmed in Interactive Data Language (IDL; Harris Geospatial Solutions, Broomfield, Colorado). The HyMap reflectance data are provided and described in this data release. MICA identifies the spectrally predominant mineral(s) in each pixel of imaging spectrometer data by comparing continuum-removed spectral features in the pixel’s reflectance spectrum to continuum-removed absorption features in reference spectra of minerals, vegetation, water, and other materials. Linear continuum removal is a technique to isolate an absorption feature from background spectral variations (Clark and Roush, 1984). Following continuum removal of a spectral feature in a reference spectrum and the corresponding channels in an imaging spectrometer pixel, the coefficient of determination (r2) of a linear regression of these continuum-removed values is used as the metric to judge the degree of match (or fit) between the unknown and reference spectra. MICA analysis is controlled by a command file, which lists the reference spectra for comparison to imaging spectrometer pixel spectra, the wavelength regions for continuum removal and spectral feature comparison, and other parameters (see Kokaly, 2011). For each pixel, the reference spectrum with the highest fit value identifies the predominant mineral class. The reference spectra used in this MICA analysis are available to the public in the USGS spectral library (Kokaly and others, 2017). The MICA command file used in this study was adapted from that used to process HyMap data covering Afghanistan (Kokaly and others, 2013). The MICA command file is provided in this data release and also in the digital appendix of Graham and others (2018).

Access & Use Information

Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

Downloads & Resources

Dates

Metadata Created Date June 1, 2023
Metadata Updated Date July 6, 2024

Metadata Source

Harvested from DOI EDI

Additional Metadata

Resource Type Dataset
Metadata Created Date June 1, 2023
Metadata Updated Date July 6, 2024
Publisher U.S. Geological Survey
Maintainer
@Id http://datainventory.doi.gov/id/dataset/89ca6fd6b86435e3e8596aa38874e5f1
Identifier USGS:59ee7d13e4b0220bbd976365
Data Last Modified 20200929
Category geospatial
Public Access Level public
Bureau Code 010:12
Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
Metadata Catalog ID https://datainventory.doi.gov/data.json
Schema Version https://project-open-data.cio.gov/v1.1/schema
Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
Harvest Object Id 10a03e88-4dff-417d-8232-2e7cfc385357
Harvest Source Id 52bfcc16-6e15-478f-809a-b1bc76f1aeda
Harvest Source Title DOI EDI
Metadata Type geospatial
Old Spatial -143.385752,61.9420478,-140.943323,62.4499567
Publisher Hierarchy White House > U.S. Department of the Interior > U.S. Geological Survey
Source Datajson Identifier True
Source Hash f8680f3b3a22c90891ce323a99a1f2b192791b920ec9de2e7ddffd7e1fc92be5
Source Schema Version 1.1
Spatial {"type": "Polygon", "coordinates": -143.385752, 61.9420478, -143.385752, 62.4499567, -140.943323, 62.4499567, -140.943323, 61.9420478, -143.385752, 61.9420478}

Didn't find what you're looking for? Suggest a dataset here.