Multi-spectral and Hyper-spectral Remote Sensing

Lectures 6October 2, 2007

Multispectral Remote Sensing

Multispectral remote sensing is defined as the collection of reflected, emitted, or backscattered energy from an object or area of interest in multiple bands of electromagnetic spectrum; while Hyperspectral remote sensing involves data collection in hundreds of bands.

Instead of cameras and 1 to 4 bands for photogrammetry, Remote sensing use detectors that are sensitive to from multiple bands to hundreds of bands in the electromagnetic spectrum. Measurements made by detectorsare always stored in a digital format (as BSQ, BIP, or BIL)

Ustin, 2003

Landsat satellite series

Jensen, 2000Jensen, 2000Jensen, 2000

MSS TM ETM+0.5-0.6 0.45-0.52 0.45-0.520.6-0.7 0.52-0.60 0.52-0.610.7-0.8 0.63-0.69 0.63-0.690.8-1.1 0.76-0.90 0.78-0.9010.4-12.6 1.55-1.75 1.55-1.75

10.4-12.5 10.4-12.52.08-2.35 2.09-2.35

0.52-0.9079m 30 30240m 120 60

156 bits 8 8103 m/c 99 9918 days 16 16 919km 705 705185km 185 185

Inclination (99º) of the Landsat Orbit to Maintain A Sun-synchronous Orbit

Inclination (99Inclination (99ºº) of the Landsat Orbit to ) of the Landsat Orbit to Maintain A SunMaintain A Sun--synchronous Orbitsynchronous Orbit

99Þ

Landsat at 12:30 p.m. local time

Equatorial plane and

direction of Earth

rotation

Landsat at 9:42 a.m. local time

N

SJensen, 2000Jensen, 2000Jensen, 2000

MSS 99ºTM 98.2ºSun-synchronous orbit mean

that the orbital plane processed around Earth at the same angular rate at which Earth moved around the SunThe satellite cross the equator at approximately the same local time (9:30 to 10:00 am)Orbit the Earth once every 103 minutes, resulting in 14 orbits per day.

Today’s Landsat 7 orbits and acquisition

http://landsat7.usgs.gov/pathrows.php

TexasView Remote Sensing Consortium

Free Landsat 7 imagery available from TexasView

http://www.texasview.org/pages/archives/html/landsat.html

GOES satellites provide the kind of continuous monitoring necessary for intensive data analysis. They circle the Earth in a geosynchronous orbit, which means they orbit the equatorial plane of the Earth at a speed matching the Earth's rotation. This allows them to hover continuously over one position on the surface

http://www.oso.noaa.gov/goesstatus/

GOES

http://antwrp.gsfc.nasa.gov/apod/ap050829.html

GOES 13 Launched May 24, 2006

NOAA will put GOES-13 into on-orbit storage at 105W until it is needed to replace GOES-12 at GOES-EAST or GOES-11 at GOES-WEST, circa 2010Know more about GOES-13?

http://goes.gsfc.nasa.gov/text/goesnstatus.htmlhttp://rammb.cira.colostate.edu/projects/goes_n/http://www.n2yo.com/satellite.php?s=29155

Advanced Very High Resolution Radiometer (AVHRR) Bandwidths

Advanced Very High Advanced Very High Resolution Radiometer Resolution Radiometer (AVHRR) Bandwidths(AVHRR) Bandwidths

9.5 10 10.5 11.511 12

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3.3 3.4 3.5 3.7 3.93.6 3.8

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1.1 km

Jensen, 2000Jensen, 2000Jensen, 2000

Advanced Very High Resolution Radiometer (AVHRR) Mosaic of the Conterminous United States

Advanced Very High Resolution Radiometer Advanced Very High Resolution Radiometer (AVHRR) Mosaic of the Conterminous United States(AVHRR) Mosaic of the Conterminous United States

Jensen, 2000Jensen, 2000Jensen, 2000

Global Normalized Difference Vegetation Index (NDVI) Image Produced Using Advanced Very High Resolution Radiometer (AVHRR) Imagery

Global Normalized Difference Vegetation Index Global Normalized Difference Vegetation Index (NDVI) Image Produced Using Advanced Very (NDVI) Image Produced Using Advanced Very High Resolution Radiometer (AVHRR) ImageryHigh Resolution Radiometer (AVHRR) Imagery

Jensen, 2000Jensen, 2000Jensen, 2000

Chronological Launch History of the SPOT SatellitesChronological Launch History of the SPOT SatellitesChronological Launch History of the SPOT Satellites

Jensen, 2000Jensen, 2000

b.Vertical viewingOblique viewing Oblique viewing

SPOT sensor

(HRV or HRVIR)

Calibration unit

Calibration unit

a.

HRV 1 (SPOT 1-3)

or HRVIR 1 (SPOT 4)

60 km

Vegetation sensor (SPOT 4)

HRV 2 (SPOT 1-3)

or HRVIR 2 (SPOT 4)

Strip- selection

mirror

60 km swath width

Equator

117 km total width

3 km overlap

HRV or HRVIR sensors

BusSolar panel

OrbitSPOT Nadir

Viewing

c.

SPOT Satellite System

Components

SPOT Satellite SPOT Satellite System System

ComponentsComponents

Courtesy of SPOT Image, Inc.

Courtesy of Courtesy of SPOT Image, Inc.SPOT Image, Inc.

Jensen, 2000Jensen, 2000

Geographic Coverage of the SPOT HRV and Landsat Thematic Mapper Remote Sensing Systems

Geographic Coverage of the SPOT HRV and Landsat Geographic Coverage of the SPOT HRV and Landsat Thematic Mapper Remote Sensing SystemsThematic Mapper Remote Sensing Systems

Jensen, 2000Jensen, 2000

Multi-angle Imaging Spectroradiometer

(MISR) Onboard Terra

MultiMulti--angle Imaging angle Imaging SpectroradiometerSpectroradiometer

(MISR) Onboard (MISR) Onboard TerraTerra

70.5Þ Df

60Þ Cf

45.6Þ Bf

0Þ nadir

70.5Þ Da 60Þ Ca

26.1Þ Af

26.1Þ Aa 45.6Þ Ba

425 – 467 nm

Sensors

View angle 70.5Þ 60Þ 60Þ 70.5Þ 45.6Þ 45.6Þ 26.1Þ 26.1Þ 0Þ

Df Cf Bf Af An Aa Ba Ca Da

275 x 275 m 1.1 x 1.1 km 275 m x 1.1 km

543 – 571 nm

660 – 682 nm

846 – 886 nm

Nadir is the point of the Earth surface thatis vertically downward from the observer

Jensen, 2000Jensen, 2000

f: forward, a: after

IKONOS Panchromatic Images of Washington, DC

IKONOS IKONOS Panchromatic Images Panchromatic Images of Washington, DCof Washington, DC

Jensen, 2000Jensen, 20001 x 1 m spatial resolution1 x 1 m spatial resolution1 x 1 m spatial resolution

IKONOS Panchromatic Stereopair of Columbia, SC AirportIKONOS Panchromatic IKONOS Panchromatic StereopairStereopair of Columbia, SC Airportof Columbia, SC Airport

Jensen, 2000Jensen, 2000 November 15, 2000November 15, 2000November 15, 2000

IKONOS Imagery of Columbia, SC Obtained on October 28, 2000IKONOS Imagery of Columbia, SC Obtained on October 28, 2000IKONOS Imagery of Columbia, SC Obtained on October 28, 2000

Panchromatic 1 x 1 mPanchromatic 1 x 1 mPanchromatic 1 x 1 m Pan-sharpened multispectral 1 x 1 mPanPan--sharpened multispectral 1 x 1 msharpened multispectral 1 x 1 m

Terra launched 12/18/1999

Earth Observing System Aqua – PM (launched 5/4/02)

mission is collecting about the Earth's water cycle, including evaporation from the oceans, water vapor in the atmosphere, clouds, precipitation, soil moisture, sea ice, land ice, and snow cover on the land and ice. Additional variables also being measured by Aqua include radiative energy fluxes, aerosols, vegetation cover on the land, phytoplankton and dissolved organic matter in the oceans, and air, land, and water temperatures The six instruments are - AIRS: the Atmospheric Infrared Sounder - AMSU-A : the Advanced Microwave Sounding Unit, - HSB: the Humidity Sounder for Brazil ,- AMSR-E: the Advanced Microwave Scanning Radiometer for EOS,- MODIS: the Moderate-Resolution Imaging Spectroradiometer, and - CERES Clouds and the Earth's Radiant Energy System.

All Terra and Aqua and many other data can be downloaded from: http://edcimswww.cr.usgs.gov/pub/imswelcome/

Information about Terra: http://terra.nasa.gov/ and Aqua: http://aqua.nasa.gov

Earth Observing System Aura (launched 7/15/04)

The Aura mission researches the composition, chemistry and dynamics of the Earth’s atmosphere as well as the ozone, air quality and climate. The six instruments are - HIRDLS: HIgh Resolution Dynamics Limb Sounder - MLS : Microwave Limb Sounder - OMI: Ozone Monitoring Instrument- TES: Tropospheric Emission Spectrometer

Information about Aura: http://aura.gsfc.nasa.gov/index.html

Summary

Ustin, 2003

Hyper-spectral remote sensing

Many remote sensing systems record energy over several separate wavelength ranges at various spectral resolutions. These are referred to as multi-spectral sensors. Advanced multi-spectral sensors called hyperspectral sensors, detect hundreds of very narrow spectral bands throughout the visible, near-infrared, and mid-infrared portions of the electromagnetic spectrum. Hyper-: Narrow bands (≤ 20 nm in resolution or FWHM) and continuous measurements.Imaging spectrometry: the simultaneous acquisition of images in many relatively narrow, contiguous and/or non-contiguous spectral bands throughout the ultraviolet, visible, and infraredportions of the spectrum.The very high spectral resolution facilitates fine discrimination between different targets based on their spectral response in each of the narrow bands

Source: http://satjournal.tcom.ohiou.edu/pdf/shippert.pdf

Airborne Visible Infrared Imaging

Spectrometer (AVIRIS) Datacube of

Sullivan’s Island Obtained on

October 26, 1998

Airborne Visible Airborne Visible Infrared Imaging Infrared Imaging

Spectrometer Spectrometer (AVIRIS) Datacube of (AVIRIS) Datacube of

SullivanSullivan’’s Island s Island Obtained on Obtained on

October 26, 1998October 26, 1998

Jensen, 2000Jensen, 2000

Linear and Area Arrays

Hyperion (EO-1, NASA)220 bands: 400-2500 nm, band width 10 nmPixel size 30 x 30 m, swath width 7.5 km11/21/2000 to present, it is the first satellite-based hyperspectral remote sensor.

Science information: http://eo1.gsfc.nasa.gov/overview/eo1Overview.html

Data order from: http://edc.usgs.gov/products/satellite/eo1.html

Hyper- and Multi- spectrum comparison

0

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250 500 750 1000 1250 1500 1750 2000 2250 2500

Wavelength (nm)

Ref

lect

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average shrub

average grass

average soil

1 2 3 4 5 7

TM image Band 1 to Band 7

Continuous hyperspectral curve for any one pixel in an image

Ustin, 2003

Summary table: current and recent hyderspectral sensors

ESA Mars ExpressOMEGA 351 0.35 to 5.12 µm

7 or 4 nm in 0.5-1.1 microns13 nm in 1.0-2.7 microns20 nm in 2.6-5.2 microns

Spectral resolution:

Spatial resolution: 300 m – 5 km

(8 to 12.5 µm)

Cont’

Hyperspectral sensors on Mars orbit

TES -- Thermal Emission Spectrometer (s. r. 3Km ), on board the Mars Global Surveyor, 1997, NASA (will be covered in the Thermal Remote Sensing lecture)

OMEGA -- Visible and Infrared Mineralogical Mapping Spectrometer (s. r. 0.3 - 4Km), on board the Mars Express, 2003, ESA

CRISM--Compact Reconnaissance Imaging Spectrometer for Mars (s. r. 18 m), on board the Mars Reconnaissance Orbiter, 2005, NASA

What is OMEGA ?

OMEGA - Visible and Infrared Mineralogical Mapping Spectrometer

352 contiguous spectral bands Covering 0.35 to 5.1 µm Spectral resolution of 7 nm to 20 nmSpatial resolution of 0.3 to 4 km/pixel

Surface mineralogy revealed by OMEGA

Mafic and ultramafic minerals (pyroxene and olivine)Surface CO2 and H2O ice and frosts Hydrated sulfates (gypsum, kieserite, and polyhydratedsulfates) on light-toned layered terrainsHydrated alteration phyllosilicates (nontronite, chamosite, and montmorillonite)Iron oxides and oxhydroxides (hematite and jarosite) related to liquid water processes

From: Bibring et al. 2005; Mustard et al., 2005; Poulet et al, 2005; Gendrin et al. 2005; Langevin et al, 2005; Arvidson et al, 2005; Combe et al, 2005. all in Science vol. 307

Identification of Olivine (J. F. Mustard et al., 2005)

Yellow - OMEGA I/F of Terrain A Red - OMEGA I/F of Dusty TerrainBlue - lab spectra of Fe-rich olivine (Fayalite) Green - lab spectra of Mg-rich olivine (Forsterite)Black - ratio of (Terrain A)/(Dusty Terrain)

Red - olivine absorption-band strengths > 10%Blue - no olivine detected with this parameter

http://crism.jhuapl.edu/