1. Remote Sensing Image Acquisition
Supplement to Lecture 1
material prepared by R. Lathrop 9/99
updated 2/06
includes slides previously prepared by S. Madry and C. Colvard
Readings:
ERDAS Field Guide 5th Ed. Ch 1, 3:56-82

2. 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

3. 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

4. Aerial Cameras Keystone’s Wild RC-10 mapping camera
A large format oblique camera

5. Aerial photos Black & White - single panchromatic layer
Color: 3 layers B-G-R
Color IR: 3 layers G-R-NIR

6. USGS Aerial Photo Products
Aerial Products Description
National Aerial Photography Program (NAPP) Recent,high-quality aerial photos covering the conterminous U.S. on five- to seven-year cycles ( present).
National High Altitude Photography (NHAP) High-altitude aerial photos for the conterminous U.S. ( ).
Digital Orthophoto Quadrangles (DOQs) 
Digital images of aerial photos which combine the image characteristics of the photo with the georeferenced qualities of a map ( present).
Space Acquired Photography 
Photos taken from the International Space Station (ISS), Shuttle (including Large Format camera), Skylab, Gemini, and Apollo missions ( present).
For more info:

7. 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
National Archives and Records Administration archives older (pre- 1950’s) aerial photography

8. Aerial Photographic Sources
National Ocean Survey (NOS) coastal photography: (since 1945), color, scales of 1;10, :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.

9. NASA Astronaut Photography

10. 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

11. 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 ( ).
For more info:
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

12. Digital Mapping Camera: Zeiss/Intergraph Imaging
2d CCD matrix (array) to ensure a rigid image geometry similar to a traditional precision film platen
Panchromatic 7000 x 4000 pixels
Color 3000 x 2000 pixels
Separate lens for each band
Multiple smaller camera heads to create image rather than a single, large diameter
12 bit radiometric resolution

13. Digital Line Sensing Systems: Leica Airborne Digital Sensor (ADS40)
Pushbroom linear array system rather than a 2D framing system
3 line scanners : forwards, downwards and backwards to provide for stereoscopic coverage
Three CCD sensors: B&W color (RGB) & NIR
12,000 pixels across
RGB co-registration through special trichroid filter that splits beam from single lens, rather than 3 different lens
Field of View of 64o
Produces up to 100GB of data per hour of flight

14. Compact Airborne Spectrographic Imager (CASI)
Hyperspectral: 288 channels between mm; each channel 0.018mm wide
Spatial resolution depends on flying height of aircraft
CASI 550
For more info:

15. Space-borne Remote Sensing
Still Emerging Technology
Pro:
GIS ready
fast turn around
acquisition time of 5 minutes gives equal solar illumination, shadows
long term archive of repeat imagery for change detection
Con:
Significant investment in infrastructure
Less flexibility in acquisition

16. Remote Sensing Satellites in Space: How do they get there?

17. MODIS Terra Launches

18. Types of satellite orbits
Geostationary Polar km
35,800 km

19. Polar Orbitting Satellite

20. 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 underneath
the sensor. Keeps the same general solar time as it cross the equator on each orbit - called sun synchronous
Polar orbit

21. Many different systems - which to choose?

22. 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

23. AVHRR Thermal AVHRR provides water temperature data 3 bands in TIR
Gulf Stream

24. 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:

25. Global AVHRR composite
1 band in the Red: um
1 band in the NIR: um
Vegetation Index to map vegetation amount and productivity

26. Remote Sensing of the Earth: Clues to a Living Planet
You can access these images over the INTERNET
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.

27. 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?

28. Can you see the Green Wave?

29. 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.

30. North America: Close-up

31. 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

32. After a picture-perfect launch into space December 1999, Terra
Began releasing images April 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:

33. MODIS TERRA in Orbit

34. 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:

35. 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:

36. “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.
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 For more info:

37. ENVISAT
In March 2002, the European Space Agency launched Envisat, an advanced polar-orbiting Earth observation satellite which provides measurements of the atmosphere, ocean, land, and ice.

38. ENVISAT: primary instruments for land/sea surface remote sensing
ASAR - Advanced Synthetic Aperture Radar, operating at C-band,
MERIS - is a 68.5 o field-of-view pushbroom imaging spectrometer that measures the solar radiation reflected by the Earth, at a ground spatial resolution of 300m, in 15 spectral bands, programmable in width and position, in the visible and near infra-red. MERIS allows global coverage of the Earth in 3 days.

39. SPOT Vegetation
Earth observation sensor on board of the SPOT satellite in blue, red, NIR & SWIR
Daily coverage of the entire earth at a spatial resolution of 1 km
The first VEGETATION instrument is part of the SPOT 4 satellite and a second payload, VEGETATION 2, is now operationally operated onboard SPOT 5.

40. SPOT Vegetation Spectral Bands

41. SPOT Vegetation Free products are :
extracts from ten day global syntheses.
available 3 months after insertion in the VEGETATION archive.
in full resolution (1km).
in plate carrée projection.
available on 10 predefined regions of interest.
in the standard VEGETATION product format.

42. ERTS-1 Earth Resources Technology Satellite-1
Renamed Landsat Multispectral scanner (MSS)
First images in late 1972
Was the first civil remote sensing satellite

43. Landsat MSS bands 4 and 5
GREEN
RED

44. Landsat MSS bands 6 and 7 INFRARED 1 INFRARED 2
Note: water absorbs IR energy-no return=black
INFRARED 1
INFRARED 2

45. MSS color composite combining bands creates a false color composite
Manhattan
Rutgers
combining bands creates a false color composite
red=vegetation
light blue=urban
black=water
pink=agriculture
Philadelphia
Pine barrens
Chesapeake
Bay
Delaware River

46. Landsat 4-5 Thematic Mapper (TM)

47. Cross-track scanning system

48. Landsat TM-7 bands-8 bit data
Spectral
(where we look)
Radiometric
(how finely can we
measure the return)
0-63, 0-255,
Landsat TM BAND

49. Spectral wavebands of Landsat TM

50. Landsat TM: each waveband provides different information about earth surface features

51. Thermal imagery-temperature
Water analysis-nuclear power cooling ponds)

52. Blew up at launch

53. Commercialization of Landsat
Landsat was commercialized by Pres. Reagan
EOSAT formed
sales dropped

54. 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:

57. SLC-on
SLC-off
On May , the Landsat 7 ETM sensor had a malfunction and the Scan Line Corrector failed which means there are gaps in data collection that are especially exacerbated towards the edge of the imagery.
All Landsat 7 ETM+ scenes acquired after July 14, 2003 were collected in Scan Line Corrector-off mode.
Landsat 7 ETM+ scenes acquired from 5/31/03 - 7/14/03 and 9/3/03 - 9/17/03 are not available
Source: US Geological Survey
Source: U.S. Geological Survey

58. Landsat 7 ETM with SLC-off

59. Earth Observing 1 NASA’s New Millennium Program
Multispectral instrument that is a significant improvement over the Landsat 7 ETM+ instrument – Advanced Line Imager (ALI)
Hyperspectral land imaging instrument – Hyperion
Low-spatial/high-spectral resolution imager that can correct systematic errors in the apparent surface reflectances caused by atmospheric effects, primarily water vapor - Linear Etalon Imaging Spectrometer Array (LEISA) Atmospheric Corrector (LAC)

60. EO-1: Advanced Line Imager (ALI)
The EO-1 ALI operates in a pushbroom fashion at an orbit of 705 km, 16 day repeat cycle. Launched in Nov 2000.
ALI provides Landsat type panchromatic and multispectral bands. These bands have been designed to mimic six Landsat bands with three additional bands covering , , and µm.
The ALI has 30M resolution multi-spectral 10m panchromatic. 37km swath width.
More info:
Mt. Fuji Japan ALI Bands: 6,5,4.

61. EO-1: Hyperion
The Hyperion collects 220 unique spectral channels ranging from to micrometers with a 10-nm bandwidth.
The instrument operates in a pushbroom fashion, with a spatial resolution of 30 meters for all bands.
The standard scene width is 7.7 kilometers. Standard scene length is 42 kilometers, with an optional increased scene length of 185 kilometers
More info:
Mt. Fuji, Japan Hyperion bands 215, 54, 15

62. EO-1
ALI & Hyperion designed to work in tandem

63. Will have 2.5 m in 1999 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

64. Panchromatic (PAN) sensor: 10 m GRC
Pan um
High Resolution Visible (HRV) sensor: 20m GRC
G (.5-.59), R ( ), NIR ( )
Ground Swath Width of 60 km
For more info go to:

65. SPOT before/after launch

66. SPOT ground stations

67. SPOT 4 1st images taken March 31, 1998

68. Polar Sun synchronous orbit
2 side-by-side HRV sensors

69. SPOT has steerable mirror

70. Stereo imaging

71. Indian Remote Sensing (IRS) satellite
IRS-1C launched in December 1995
IRS1D launched in September 1997
Panchromatic: um
5.8 m GRC, 30 km ground swath
22 day repeat cycle with off-nadir pointability

72. IRS RESOURCESAT-1
RESOURCESAT-1 launched into its 817 km orbit on Oct. 17, 2003
A high-resolution Linear Imaging Self Scanner (LISS-4) operating in three spectral bands in the visible and near-infrared region with 5.8-meter resolution and steerable up to ± 26 degrees across track to obtain stereoscopic imagery and achieve five-day revisit capability.
A medium-resolution LISS-3 sensor operating in four spectral bands in visible, near-infrared and short wave infrared with 23-meter resolution.
An Advanced Wide Field Sensor (AWiFS) operating in four spectral bands in visible, near-infrared and one short wave infrared with 56-meter resolution. * In addition, RESOURCESAT-1 has a solid-state recorder with a capacity of 120 gigabits to store the images taken by its cameras.

73. Formosat-2
The Taiwanese FORMOSAT-2 satellite developed for the NSPO (National SPace Organization) was successfully launched on 20 May 2004.
FORMOSAT-2’s can acquire any scene in its coverage area each day (due to its geosynchronous orbit) with off-nadir capability (up to +/- 45°) both along track (forward and backward looking) and across track (side looking).
black and white images with 2-m resolution,
color images with 8-m resolution (4 spectral bands: near infrared, red, green and blue),
each scene covers 24 km x 24 km.
Distributed by SpotImage

74. Space Imaging IKONOS Panchromatic (045-0.9 um): 1 m
Multispectral: 4 m Blue ( nm), Green( nm) Red ( nm) NIR ( nm)
11 km swath width
Pointable to 45o for daily viewing
For more info go to:

75. IKONOS SAMPLE IMAGERY
Multi-spectral
4m GRC
Pan-chromatic
1m GRC

76. Space Imaging IKONOS Imagery Sample: Bound Brook NJ
1 m panchromatic
4 m multi-spectral

77. OrbView-3
Panchromatic: 1 m
Multispectral (color): 4 m
Pointable: anywhere on globe within 3 days
Additional hyperspectral sensor
For more info go to:

78. Wishful thinking!
OrbView4 did not achieve orbit on launch on Sept 21, 2001

79. OrbView 5: upping the ante
Scheduled for launch in early 2007, OrbView-5 will simultaneously acquiring 0.41-meter panchromatic and 1.64-meter multispectral (B-G-R-NIR) imagery.
Swath width: 15.2 km
11 bits per pixel
Revisit Time: <3 days

80. Quickbird
DigitalGlobe™ successfully launched its QuickBird satellite on the Boeing Delta II launch vehicle on October 18, 2001.
Panchromatic: m
Multispectral (color): 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

81. Different sensors and resolutions
sensor spatial spectral radiometric temporal
AVHRR and 4 KM or 5 bands bit hours
2400 Km , , (0-1023) (1 day, 1 night)
, (micrometers)
Landsat MSS meters bands bit days
185 Km , .6-.7, .7-.8, (0-63)
Landsat TM 30 meters bands bit days
185 Km , , , (0-255)
.76-.9, ,
, um
SPOT P meters band bit days
60 Km um (0-255) (2 out of 5)
SPOT X meters bands bit days
60 Km , , um (0-255) (2 out of 5)
IKONOS and 4 meters and 4 bands bit days
11 km , , , (0-1023) ,

82. For a recent review of land imaging satellites refer to the Guide to Land Imaging Satellites online at ASPRS

83. Sources for downloadable imagery
Download Landsat, ASTER, MODIS, Quickbird, SRTM,
NASA Stennis Space Center Download Landsat 1990/2000 imagery as Mr. Sid format
NASA Worldwind Visualization software that includes Landsat 7, MODIS, SRTM

84. Homework 1: Selecting and Ordering Imagery
1. Enhanced Landsat Thematic Mapper 7 (ETM+) imagery is available through the U.S. Geological Survey. Go to the USGS’ Earth Explorer web site ( or their newer, better web browser (
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 area
D. 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?

85. Homework 1: Selecting and Ordering Imagery
2. The OrbImage Corporation ( 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 ( 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?

86. Good Bye from Planet Earth
Source