Remote Sensing Data Acquisition 1 Major Remote Sensing

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Remote Sensing Data Acquisition

Remote Sensing Data Acquisition

1. Major Remote Sensing Systems

1. Major Remote Sensing Systems

Major Remote Sensing Systems ► Aerial photography ► Electro-Optical remote sensing ► Microwave remote

Major Remote Sensing Systems ► Aerial photography ► Electro-Optical remote sensing ► Microwave remote sensing ► Close range remote sensing

Aerial Photography ► Detector ► Process ► Vehicle ► Products: aerial photographs

Aerial Photography ► Detector ► Process ► Vehicle ► Products: aerial photographs

► http: //nationalmap. gov/viewer. html ► http: //www. abc. net. au/news/events/japan-quake 2011/beforeafter. htm

► http: //nationalmap. gov/viewer. html ► http: //www. abc. net. au/news/events/japan-quake 2011/beforeafter. htm

Electro-Optical Remote Sensing ► Detector ► Process ► Vehicle ► Products: Digital images

Electro-Optical Remote Sensing ► Detector ► Process ► Vehicle ► Products: Digital images

Buffalo, NY November 20, 2000 http: //earthobservatory. nasa. gov/Newsroom/Ne w. Images/images. php 3? img_id=4396

Buffalo, NY November 20, 2000 http: //earthobservatory. nasa. gov/Newsroom/Ne w. Images/images. php 3? img_id=4396

Biloxi Coast–Before Hurricane Katrina, April 12, 2005 Biloxi Coast–After Hurricane Katrina, August 31, 2005.

Biloxi Coast–Before Hurricane Katrina, April 12, 2005 Biloxi Coast–After Hurricane Katrina, August 31, 2005. http: //www. esri. com/news/pressroom/hurricanemaps. html

Microwave Remote Sensing ► Uses antennas as detectors ► Passive microwave systems ► Active

Microwave Remote Sensing ► Uses antennas as detectors ► Passive microwave systems ► Active microwave systems, RADAR

http: //rst. gsfc. nasa. gov/Sect 8_3. html http: //www. erh. noaa. gov/buf/

http: //rst. gsfc. nasa. gov/Sect 8_3. html http: //www. erh. noaa. gov/buf/

Close Range Remote Sensing

Close Range Remote Sensing

► Visual interpretation vs. digital image processing

► Visual interpretation vs. digital image processing

2. Resolutions ► Spectral resolution ► Radiometric resolution ► Spatial resolution ► Temporal resolution

2. Resolutions ► Spectral resolution ► Radiometric resolution ► Spatial resolution ► Temporal resolution

Spectral Resolutions French SPOT Landsat 7 DS-1260 AVIRIS 1. 0 mm 2. 0 mm

Spectral Resolutions French SPOT Landsat 7 DS-1260 AVIRIS 1. 0 mm 2. 0 mm

Spectral Resolutions ► The dimension and the number of specific wavelength intervals in the

Spectral Resolutions ► The dimension and the number of specific wavelength intervals in the EM spectrum to which a sensor is sensitive, e. g. B, G, R NIR bands Green Red Near Infrared http: //rst. gsfc. nasa. gov/Intro/Part 2_17. html NIR

Radiometric Resolution ► The sensitivity of a detector to differences in signal strength as

Radiometric Resolution ► The sensitivity of a detector to differences in signal strength as it records the radiant flux reflected or emitted from the terrain 8 bit 4 bit 2 bit 1 bit 256 levels 16 levels 4 levels 2 levels

Spatial Resolution ► A measure of the smallest angular or linear separation between two

Spatial Resolution ► A measure of the smallest angular or linear separation between two objects that can be resolved by the sensor, 30 m, 1 km 10 m 20 m 40 m 80 m

Temporal Resolution ► How often a given sensor obtains imagery of a particular area,

Temporal Resolution ► How often a given sensor obtains imagery of a particular area, e. g. , 16 days, daily

Pixels and IFOV ► Pixel - picture element ► IFOV - Instantaneous Field of

Pixels and IFOV ► Pixel - picture element ► IFOV - Instantaneous Field of View the ground area viewed by the sensor at a given instant

3. Color Theory ► Additive primaries ► Subtractive primaries

3. Color Theory ► Additive primaries ► Subtractive primaries

Additive Primaries ► blue, green, and red superimposing blue, green, and red light: blue

Additive Primaries ► blue, green, and red superimposing blue, green, and red light: blue + green + red = white green + red = yellow green + blue = cyan red + blue = magenta

Color Theory ► Yellow, magenta, and cyan are complements of blue, green, and red,

Color Theory ► Yellow, magenta, and cyan are complements of blue, green, and red, respectively ► Various combinations of the three primaries produce different colors

Subtractive Primaries ► yellow, magenta, and cyan each absorbs its complementary color from white

Subtractive Primaries ► yellow, magenta, and cyan each absorbs its complementary color from white light yellow = white - blue magenta = white - green cyan = white - red

Subtractive Primaries ► Superimposing yellow, magenta, and cyan dye: yellow + magenta + cyan

Subtractive Primaries ► Superimposing yellow, magenta, and cyan dye: yellow + magenta + cyan = black yellow + magenta = red yellow + cyan = green magenta + cyan = blue

True and False Color Images

True and False Color Images

True and False Color Images http: //www. crisp. nus. edu. sg/~research/tutorial/opt_int. htm

True and False Color Images http: //www. crisp. nus. edu. sg/~research/tutorial/opt_int. htm

► Readings Chpt 2. 7

► Readings Chpt 2. 7

4. Introduction of Satellite Systems ► Land observation satellite systems vehicles - spacecraft devices

4. Introduction of Satellite Systems ► Land observation satellite systems vehicles - spacecraft devices - electro-optical sensors images - digital images target - earth resources

Satellite Systems ► Advantages vs. aerial photography provide a synoptic view systematic, repetitive coverage

Satellite Systems ► Advantages vs. aerial photography provide a synoptic view systematic, repetitive coverage multiple spectral information digital format for quantitative analysis less expensive

History of Satellite Systems ► Landsat (Land Satellite) system - launched in 1972 -

History of Satellite Systems ► Landsat (Land Satellite) system - launched in 1972 - first satellite for observation of the earth's land areas - important in earth resources studies and a model for later satellite systems

History of Satellite Systems ► Early Landsat (1, 2, 3) was named Earth Resources

History of Satellite Systems ► Early Landsat (1, 2, 3) was named Earth Resources Technology Satellite (ERTS) and designated by a letter, i. e. A, B, C, renamed later as Landsat 1, 2, 3 ► Early Landsat applied spectrums used in aerial photography but at a satellite altitude ► Early Landsat carried Return Beam Vidicon (RBV) and Multispectral Scanner (MSS) sensor systems ► New generation of Landsat (4, 5, 7) carries MSS and Thematic Mapper (TM) and other more sophisticated sensor systems

Satellite Orbits ► Geosynchronous orbits ► Sun-synchronous orbits ► Inclination ► Ascending and descending

Satellite Orbits ► Geosynchronous orbits ► Sun-synchronous orbits ► Inclination ► Ascending and descending nodes

Geosynchronous Orbits ► Revolve at an angular rate that matches the earth's rotation ►

Geosynchronous Orbits ► Revolve at an angular rate that matches the earth's rotation ► Weather satellites, communication satellites ► Views the full range of variation of solar illumination http: //www. crisp. nus. edu. sg/~research/tutorial/spacebrn. htm

Sun-Synchroneous Orbits ► Maintain a constant angular relationship with the solar beam, the satellite

Sun-Synchroneous Orbits ► Maintain a constant angular relationship with the solar beam, the satellite will always pass overhead at the same local time for similar illumination and shadowing conditions http: //www. youtube. com/watch? v=Ltt. I 1 Iof. XRI http: //www. crisp. nus. edu. sg/~research/tutorial/spacebrn. htm

Satellite Orbits ► Inclination the angle between the orbital plane and the equatorial plane

Satellite Orbits ► Inclination the angle between the orbital plane and the equatorial plane ► Coverage of the earth's surface http: //www. atmos. umd. edu/~owen/CHPI/IMAGES/orbitss. html

Satellite Orbits ► Descending node - the point the satellite crosses equator on southward

Satellite Orbits ► Descending node - the point the satellite crosses equator on southward track ► Ascending node - the point the satellite crosses equator on northward track http: //www. ccrs. nrcan. gc. ca/ccrs/learn/tuto rials/fundam/chapter 2_2_e. html

Satellite Orbits ► Most satellites cross over the equator at about 9: 30 am,

Satellite Orbits ► Most satellites cross over the equator at about 9: 30 am, an optimal time with respect to sun angle and cloud cover

Readings ► Chapter 6

Readings ► Chapter 6