3/31/03. ESM 266: Introduction 1. Observations from space. Remote Sensing: The Major Source for Large-Scale Environmental Information

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1 Remote Sensing: The Major Source for Large-Scale Environmental Information Jeff Dozier Observations from space Sun-synchronous polar orbits Global coverage, fixed crossing, repeat sampling Typical altitude 500-1,500 km Low-inclination, non-sun-synchronous orbits Tropics, mid-latitudes, varying sampling Typical altitude 200-2,000 km Geostationary orbits Regional views of full Earth disk, continuous coverage Over Equator only, altitude 35,000 km Observations from aircraft and ground Radiation principles Aircraft Regional and local, any sampling times Repeat sampling In situ atmospheric chemistry, clouds and aerosols, heat and vapor fluxes Sparse coverage Ground Repeat or continuous sampling Sparse coverage radiance Sun (5800K) Scaled for Earth-Sun distance Earth (288K) wavelength (µm) 4 Atmospheric absorption of solar and infrared radiation Passive and active remote sensing Passive: Source of energy is either the Sun or Earth/atmosphere Sun Wavelengths from 0.4 to 5 µm Earth or its atmosphere Wavelengths from 3 µm to 30 cm Active: Source of energy is part of the system Radar Wavelengths from mm to m Lidar Typically around 1 µm NASA Goddard Institute for Space Studies 5 ESM 266: Introduction 1

2 Measurement scale constrained by physics and technology (and money) Spatial resolution (IFOV/GSD) and coverage (field-ofview/regard) Optical diffraction sets minimum aperture size Spectral resolution ( λ) and coverage (λ min to λ max ) Narrow bands need bigger aperture, more detectors, longer integration time Radiometric resolution (S/N, NE ρ, NE T) and coverage (dynamic range) Aperture size, detector size, number of detectors, integration time Temporal resolution (revisit) and coverage (repeat) Pointing agility, period for full coverage Some current missions NOAA/AVHRR 5 spectral bands, 1.1 km at nadir, 1500 km swath 2 daily coverage with each of 3 satellites Landsat 7 spectral bands, 30 m at nadir, 185 km swath 16-day repeat Landsat 7 launch 4/99 TOPEX/Poseidon sea-surface height (and thereby circulation) SeaWiFS ocean color (and thereby productivity) TRMM(Tropical Rainfall Measuring Mission) precipitation radar, cloud imager, energy budget, lightning AVHRR (NOAA s operational weather sensor) Antenna on roof of Ellison Hall and follow link to AVHRR Sierra Nevada snow cover from Landsat 9/2/93 2/9/94 4/14/94 TRMM image of Hurricane Floyd 13 Sep 1999 TOPEX/Poseidon view of El Niño / La Niña, ESM 266: Introduction 2

3 SeaWiFS image global chlorophyll July Sept 1998 Concept of an imaging spectrometer Provided by the SeaWiFS Project, NASA/Goddard Space Flight Center and ORBIMAGE 14 Aircraft hyperspectral data (AVIRIS) Airborne Visible Infrared Imaging Spectrometer (AVIRIS) 0.4 µm λ nm at 10 nm resolution 224 spectral bands 20 m spatial resolution when flying at 11 km 2.5 µm 16 Surface wetness with AVIRIS, Mt. Rainier, 6/14/96 AVIRIS image, 409, 1324, 2269 nm precipitable water, 1-8 mm liquid water, 0-5 mm path absorption vapor, liquid, ice (BGR) ESM 266: Introduction 3

4 Springtime ozone measurements from TOMS, Atmospheric N 2 O from GOME on ERS Interferometric image from SIR-C/X-SAR A cool collection of interferometric images AltynTaghfault (full resolution image is available from the JPL SRTM image website) 22 An opportunity to beat swords into plowshares From the National Reconnaissance Organization web site In February 1995, Vice President Gore announced the declassification of U.S. CORONA spy satellite imagery archive from » Film transferred to USGS/EROS and National Archives» Digital browse images The fact that intelligence satellite data are used for mapping, charting, and geodesy» e.g. Digital Elevation Models follow links to Corona Pentagon in ESM 266: Introduction 4

5 From the USGS EROS Data Center web site Search for CORONA example from 1969 EOS the Earth Observing System TRMM ( launch November 18, 1997 Precipitation radar, TMI, VIRS, CERES, LIS Landsat 7 ( launch April 15, 1999, 8 spectral bands, m resolution, 183 km swath Terra ( launch December 18, 1999 ASTER, CERES, MISR, MODIS, MOPITT ACRIMSAT ( launch December 20, 1999 ACRIM (solar irradiance) JASON-1 ( launch December 7, 2001 Sea-surface altimeter, DORIS, GPS, laser retroreflector EOS (cont.) Images from Terra ( ) Aqua ( launch March 24, 2002 AIRS, AMSU, AMSR-E, CERES, HSB, MODIS IceSat ( launch January 12, 2003 GLAS (geoscience laser altimeter) Aura ( launch June 2003 HIRDLS, MLS, OMI, TES EOSDIS ( Hurricane Michelle, Nov 04, 2001 Mouth of Yangtze, Sep 16, ESM 266: Introduction 5