Remote Sensing Data Acquisition 1 Major Remote Sensing
- Slides: 39
Remote Sensing Data Acquisition
1. Major Remote Sensing Systems
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
► 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
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. http: //www. esri. com/news/pressroom/hurricanemaps. html
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/
Close Range Remote Sensing
► Visual interpretation vs. digital image processing
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 ► 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 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 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, e. g. , 16 days, daily
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
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, respectively ► Various combinations of the three primaries produce different colors
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 = black yellow + magenta = red yellow + cyan = green magenta + cyan = blue
True and False Color Images
True and False Color Images http: //www. crisp. nus. edu. sg/~research/tutorial/opt_int. htm
► Readings Chpt 2. 7
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 multiple spectral information digital format for quantitative analysis less expensive
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 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 nodes
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 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 ► 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 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, an optimal time with respect to sun angle and cloud cover
Readings ► Chapter 6
- Remote data acquisition
- Acquisition image
- Acquisition vs learning examples
- Limitations of remote sensing
- Remote sensing platforms
- Active vs passive remote sensing
- Ideal remote sensing system
- Digital number remote sensing
- Limitations of remote sensing
- Idealized remote sensing system
- Aggregation ap human geography
- Aggregation ap human geography
- Image parallax in remote sensing
- Strip camera in remote sensing
- Remote sensing image
- Ifov and fov in remote sensing
- Geometry of aerial photographs
- National authority for remote sensing and space sciences
- Canadian centre for remote sensing
- Distortion definition ap human geography
- Remote sensing applications center
- Remote sensing applications center
- Remote sensing physics
- Microwave remote sensing lecture notes
- Remote sensing in precision agriculture
- Aerial photography in remote sensing pdf
- Introduction to microwave remote sensing
- Remote sensing physics
- Geometric errors in remote sensing
- Remote sensing
- Lidar remote sensing for forestry
- Process
- Applied remote sensing training program
- Advantages of remote sensing
- Remote sensing
- Digital interpretation in remote sensing
- Data acquisition and data analysis
- What is data acquisition in data warehouse
- Plc data acquisition
- Spatial data acquisition