Remote Sensing Image Acquisition
description
Transcript of Remote Sensing Image Acquisition
Remote Sensing Image Acquisition
Supplement to Lecture 1
material prepared by R. Lathrop 9/99
updated 8/03
includes slides previously prepared by S. Madry and C. Colvard
Readings:
ERDAS Field Guide 5th Ed. Ch 1, 3:56-82
Digital Image Acquisition
• Digitization of analog aerial photography, can be very useful for historical studies and/or for high spatial resolution needs
• Direct acquisition using some form of digital imaging sensor
Early attempts• Kite system acquired
aerial photos of the great San Francisco earthquake and fire
• Pigeon cameras
• The development of aircraft
• World Wars I and II
Aerial photos• Black & White -
single panchromatic layer
• Color: 3 layers B-G-R
• Color IR: 3 layers G-R-NIR
USGS Aerial Photo ProductsAerial Products Description
National Aerial Photography Program (NAPP) Recent,high-quality aerial photos covering the conterminous U.S. on five- to seven-year cycles (1987 - present).
National High Altitude Photography (NHAP) High-altitude aerial photos for the conterminous U.S. (1980 - 1989).
Digital Orthophoto Quadrangles (DOQs)
Digital images of aerial photos which combine the image characteristics of the photo with the georeferenced qualities of a map (1987 - present).
Space Acquired Photography
Photos taken from the International Space Station (ISS), Shuttle, Skylab, Gemini, and Apollo missions (1965 - present).
For more info: http://edc.usgs.gov/products/aerial.html
Aerial Photographic Sources• USDA: (since 1955): mainly PAN of
1:20,000-1:40,000. These photos are archived by the Aerial Photography Field Office http://www.fsa.usda.gov/dam/APFO/airfto.htm
• National Archives and Records Administration archives older (pre- 1950’s) aerial photography http://www.nara.gov/research/ordering/mapordr.html
Aerial Photographic Sources• National Ocean Survey (NOS) coastal photography:
(since 1945), color, scales of 1;10,000 - 1:50,000• The photos are used for a variety of geo-positioning
applications, which include delineating the shoreline for Nautical Chart creation, measuring water depths, mapping seabed characteristics, and locating obstructions to marine and air navigation.
• http://mapfinder.nos.noaa.gov
Analog Image Digitization
• Can take analog photography and turn into digital images
• Scanning micro-densitometer
• Linear array charge-coupled device e.g., flat-bed scanners
• Area array charge-coupled device e.g., digital camera
Airborne Digital Imaging Systems
Aircraft Scanners Digital imagery acquired from several multispectral scanners on board NASA ER-2, NASA C-130B, and NASA Learjet aircrafts (1982 - 1995).
For more info: http://edcdaac.usgs.gov/airborne/air_scan.html
Digital Cameras increasingly aerial imagery is being acquired through digital camera framing systems that can collect multispectral (VIS-NIR) imagery and be quickly corrected through GPS-based navigational systems to produce digital orthophotographic imagery in near-real time
Space-borne Remote Sensing
Still Emerging TechnologyPro:•GIS ready•fast turn around•acquisition time of 5 minutes gives equal solar illumination, shadows•long term archive of repeat imagery for change detectionCon:•Significant investment in infrastructure•Less flexibility in acquisition
Remote Sensing Satellites in Space: How do they get there?
http://visibleearth.nasa.gov/cgi-bin/viewrecord?492
Geostationary vs. polar orbiting sensors
Geostationary sensors orbit with the earth continually viewing the same hemispheric area
Polar orbiters, continually view new areas of the earth as the planet rotates underneaththe sensor. Keeps the same general solar time as it cross the equator on each orbit - called sun synchronous
Polar orbit
• AVHRR-Advanced Very High Resolution Radiometer• Polar orbit, coarse spatial resolution: 1 and 4 km cells, broad 2400 km ground swath width• 2 operational now-1 day and 1 night pass for each
Remote Sensing of the Earth: Clues to a Living Planet
• Scientists at the NASA Goddard Space Flight Center have used the AVHRR to create maps of vegetation greenness for the entire globe
• The NASA scientists have combined numbers of satellite images to create a composite picture of the earth at approximately biweekly intervals over a number of years
For more info and images, go to: http://daac.gsfc.nasa.gov/CAMPAIGN_DOCS/BRS_SRVR/avhrrbrs_main.html
Global AVHRR composite
• 1 band in the Red: .58-.6 um
• 1 band in the NIR: .72-1.1 um
• Vegetation Index to map vegetation amount and productivity
Remote Sensing of the Earth: Clues to a Living Planet
• You can access these images over the INTERNET
• http://daac.gsfc.nasa.gov/CAMPAIGN_DOCS/LAND_BIO/GLBDST_Images.html
• You can either browse through individual images or watch an animation
• First, click on the Global 1 degree 1986 NDVI (Climate Data Set) (1.5 MB Quicktime) animation. Open it, and click on the > button. You can go more slowly by clicking on the |> button.
Remote Sensing of the Earth: Clues to a Living Planet
• First, click on the Global 1 degree 1986 NDVI (Climate Data Set) (1.5 MB Quicktime) animation. Open it, and click on the > button.
• Watch closely, can you observe the Green Wave in the northern hemisphere?
• What about the Brown Wave?
• Now look at the southern hemisphere. What do you observe?
Remote Sensing of the Earth: Clues to a Living Planet
• Now take a look at the Northern hemisphere in greater detail.
• Click on the North America 1986 NDVI (750K quicktime) Animation.
• Can you find where you live? How long does it stay green?
• Compare Florida with Maine or Minnesota.
Remote Sensing of the Earth: Clues to a Living Planet
• To access more recently acquired AVHRR imagery go to the National Oceanographic & Atmospheric Administration (NOAA) Satellite Active Archive http://www.saa.noaa.gov/
After a picture-perfect launch into space December 1999, TerraBegan releasing images April 2000. Terra includes MODIS, a 2nd generation “AVHRR-like” instrument, with a number of potential applications in regional to global scale environmental monitoring of the land, ocean and atmosphere. Also includes ASTER, CERES, MISR and MOPITT.
For more info go to: http://terra.nasa.gov/
•36 discrete bands between 0.4 and 14.5 µm
•spatial resolutions of 250, 500, or 1,000 m at nadir.
•Signal-to-noise ratios are greater than 500 at 1-km resolution (at a solar zenith angle of 70°), and absolute irradiance accuracies are < ±5% from 0.4 to 3 µm (2% relative to the sun) and 1 percent or better in the thermal infrared (3.7 to 14.5 µm).
•MODIS instruments will provide daylight reflection and day/night emission spectral imaging of any point on the Earth at least every 2 days, operating continuously.
•For more info: http://eospso.gsfc.nasa.gov/eos_homepage/mission_profiles/instruments/MODIS.php
•3 visible/NIR(VNIR: 0.5 and 0.9 µm) with 15-m resolution
•3 mid IR (SWIR: 1.6 and 2.43 µm) with 30-m res.
•5 TIR (8 and 12 µm) with 90-m resolution
•60- km swath whose center is pointable cross-track ±8.55° in the SWIR and TIR, with the VNIR pointable out to ±24°. An additional VNIR telescope (aft pointing) covers the wavelength range of Channel 3. By combining these data with those for Channel 3, stereo views can be created, with a base-to-height ratio of 0.6.
•Overpass every 16 days in all 14 bands and once every 5 days in the three VNIR channels. For more info: http://eospso.gsfc.nasa.gov/eos_homepage/mission_profiles/instruments/ASTER.php
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 AQUA Platform includes the MODIS, CERES and AMSR_E instruments. Aqua was formerly named EOS PM, signifying its afternoon equatorial crossing time. AQUA was launched May 2002. For more info: http://aqua.nasa.gov/
“Aqua,” Latin for “water,” is a NASA Earth Science satellite mission named for the large amount of information that the mission will be 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.
ERTS-1• Earth Resources
Technology Satellite-1• Renamed Landsat
Multispectral scanner (MSS)
• First images in late 1972
• Was the first civil remote sensing satellite
• combining bands creates a false color composite
• red=vegetation• light blue=urban• black=water
• pink=agriculture
Rutgers
Manhattan
PhiladelphiaPine barrensChesapeake BayDelaware River
MSS color composite
Landsat TM-7 bands-8 bit dataSpectral
(where we look)
Radiometric(how finely can wemeasure the return)0-63, 0-255, 0-1023
Landsat TM BAND 1 2 3 4 5 7 6
Commercialization of Landsat
• Landsat was commercialized by Pres. Reagan
• EOSAT formed
• sales dropped
Landsat 7
• 15 m ETM+ (enhanced TM) sensor• April 1999 launch• Oct.’92 Land remote sensing policy
act• a panchromatic band with 15m spatial
resolution-fully coregistered w/30m • on-board, full aperture, 5% absolute
radiometric calibration • a thermal IR channel with 60m
spatial resolution
•for more info go to: http://landsat.gsfc.nasa.gov/
• French commercial remote sensing system
• First launch in 1986• 10 and 20 m spatial
resolution• 60 km swath width• Stereo viewing ability
• Will have 2.5 m in 1999
Panchromatic (PAN) sensor: 10 m GRC
Pan 0.51-.73 um
High Resolution Visible (HRV) sensor: 20m GRC
G (.5-.59), R (.61-.68), NIR (.79-.89)
Ground Swath Width of 60 km
For more info go to: http://www.spotimage.fr/home/home.htm
Indian Remote Sensing (IRS) satellite
• IRS-1C launched in December 1995
• IRS1D launched in September 1997
• Panchromatic: 0.5-0.75 um
• 5.8 m GRC, 30 km ground swath
• 22 day repeat cycle with off-nadir pointability
Space Imaging IKONOS
• Panchromatic (045-0.9 um): 1 m
• Multispectral: 4 mBlue (445-516nm), Green(506-595nm)
Red (632-698nm) NIR (757-853nm)
• 11 km swath width
• Pointable to 45o for daily viewing
• For more info go to: http://www.spaceimage.com/index.htm
OrbView-3•Panchromatic: 1 m •Multispectral (color): 4 m• Pointable: anywhere on globe within 3 days•Additional hyperspectral sensor•For more info go to: http://www.orbimage.com/index.html
Quickbird •DigitalGlobe™ successfully launched its QuickBird satellite on the Boeing Delta II launch vehicle on October
18, 2001. •Panchromatic: 0.61-1m •Multispectral (color): 2.5-4 m•Can increase the resolution system by adjusting the orbit in which the satellite is flown. As a result, panchromatic resolution increases from 1 meter to 61 centimeters and multi-spectral increases from 4- to 2.5-meter resolution. •The satellite will operate in a 450-km 98-degree sun-synchronous orbit, with each orbit taking 93.4 minutes
http://www.digitalglobe.com/index.shtml
Different sensors and resolutions
sensor spatial spectral radiometric temporal----------------------------------------------------------------------------------------------------------------AVHRR 1.1 and 4 KM 4 or 5 bands 10 bit 12 hours 2400 Km .58-.68, .725-1.1, 3.55-3.93 (0-1023) (1 day, 1 night) 10.3-11.3, 11.5-12.5 (micrometers)Landsat MSS 80 meters 4 bands 6 bit 16 days 185 Km .5-.6, .6-.7, .7-.8, .8-1.1 (0-63)
Landsat TM 30 meters 7 bands 8 bit 14 days 185 Km .45-.52, .52-.6, .63-.69, (0-255) .76-.9, 1.55-1.75, 10.4-12.5, 2.08-2.3 umSPOT P 10 meters 1 band 8 bit 26 days 60 Km .51-.73 um (0-255) (2 out of 5)
SPOT X 20 meters 3 bands 8 bit 26 days 60 Km .5-.59, .61-.68, .79-.89 um (0-255) (2 out of 5)
IKONOS 1 and 4 meters 1 and 4 bands 10 bit 1-2 days 11 km .45-.9, .44-.51, .52-.60, (0-1023) .63-.70, .76-.85
Homework 1: Selecting and Ordering Imagery1. Enhanced Landsat Thematic Mapper 7 (ETM+) imagery is available through the U.S. Geological Survey. Go to the USGS’ Earth Explorer web site (http://edcsns17.cr.usgs.gov/EarthExplorer/) or their newer, better web browser (http://glovis.usgs.gov).
A. How many Landsat TM scenes are needed to image the entire state of New Jersey?
B. What are the Path/Row numbers?
C. What is the cost per square km for the ETM+ Level 1G image? Hint: 1st determine the area of the scene in km2, then divide scene cost by areaD. Using the Search Archive capabilities, determine the date of the most recent cloud-free (<20%) ETM+ image for Middlesex County, NJ. What is the Scene ID, Path/Row and date?
Homework 1: Selecting and Ordering Imagery
2. The OrbImage Corporation (www.orbimage.com/) markets OrbView and other high resolution imagery. Access the OrbImage site to get up-to-date information on pricing and availability.
A. What is the spatial accuracy and cost per square kilometer for the standard OrbView Cities product? OrbView Cities Plus?
3. DigitalGlobe (www.digitalglobe.com) markets Quickbird imagery. Access the DigitalGlobe site to get up-to-date information on pricing and availability?
A. What types of Quickbird image products are offered?