Platforms with Sensor on board GMS Illumination ( Geostationary - PowerPoint PPT Presentation

Platforms with Sensor on board GMS Illumination ( Geostationary Satellite) LANDSAT, MOS , SPOT SPACE SHUTTLE atmosphere HIGH ALTITUDE JETPLANE emission LOW&MIDDLE reflection ALTITUDE AIRPLANE GROUND TRUTH object Remote Sensing - Introduction

Conte ontents - nts - Intr ntrod oduc ucti tion to R on to RS • Principles of Remote Sensing – electromagnetic radiation – atmospheric interaction – surface reflection • Remote Sensing systems – Platforms – Sensors – Resolution: spatial, spectral, temporal • Applications of Remote Sensing Remote Sensing - Introduction

De Definiti tion of on of R Remote ote Se Sensi nsing Remote Sensing is a method to acquire information about material objects, areas, or phenomenon through the analysis of data acquired by a device from measurements made at a distance, without coming into physical contact with the objects, areas, or phenomena under investigation. Remote Sensing - Introduction

Wh Why Rem Remote S Sensin ing? g? Remote Sensing - Introduction

Wh Why Rem Remote S Sensin ing? g? Remote Sensing - Introduction

Wh Why Rem Remote S Sensin ing? g? • To recognize macro-patterns which may not be visible from ground • To gain an OVERVIEW of an area • To gather information on large areas in short time • To gather information cost-effectively • To gather information on inaccessible places • To replace conventional sources of information (topo sheets, census data etc.) Remote Sensing - Introduction

What is Remote Sensing? We acquire much information about our surrounding through the senses of sight and hearing which do not require close contact between the sensing organs and the external objects. In another word, we are performing Remote Sensing all the time. Generally, Remote sensing refers to the activities of recording/ observing/ perceiving ( sensing ) objects or events at far away ( remote ) places. Earth from Space Remote Sensing - Introduction

How does Remote Sensing Work? Electro-magnetic radiation which is reflected or emitted from an object is the usual source of remote sensing data. A device to detect the electro-magnetic radiation reflected or emitted from an object is called a "remote sensor" or " sensor ". Cameras or scanners are examples of remote sensors. A vehicle to carry the sensor is called a " platform ". Aircraft or satellites are used as platforms. The characteristics of an object can be determined, using reflected or emitted electro- magnetic radiation, from the object. Each object has a unique and different characteristics of reflection or emission if the type of object or the environmental condition is different. . Remote Sensing - Introduction

Prin inciples ples o of RS RS: E : EMR • The definition of RS implies the use of medium which carries the information from the object to the sensor • Usually, electro-magnetic radiation (EMR) is being used as medium • In passive RS , the radiation emitted by some other source is being used • In active RS , the radiation is being emitted by the system itself Remote Sensing - Introduction

Elect ectro ro-Magn -Magnet etic Rad ic Radiat iation ( (EMR) / 2 / 2 magnetic field electric field travelling direction λ (wave length) Remote Sensing - Introduction

The Electro-Magnetic Spectrum 0.3 (cm) 1 3 10 30 100 Microwave bands W V O Ka K Ku X C S L P Microwaves 0.1nm 10nm 1 µ m 100 µ m 10mm 1m 100m 10km Wavelength: γ -ray X-ray UV Vis. Infrared EHF SHF UHF VHF MF LF VLF Radio waves Visible Light y o v g e r b I r Short Inter- r l a l Thermal o Ultra Violet Near Infra-red mediate e Wave e l u n Infra-red l Infra-red e Infra-red d o g e e n w e t wavelength ( µ m) 0.4 0.6 0.8 1 5 7 10 Remote Sensing - Introduction

Charact aracter eris istics cs o of s spect ectral regio ral regions Region Wavelength Remarks Gamma Ray <0.03 nm Incoming radiation is completely absorbed by the upper atmosphere and is not available for remote sensing. X-ray 0.03 to 3.0 nm Completely absorbed by the atmosphere. Not employed in remote sensing. Ultraviolet 0.03 to 0.4 µm In-coming wavelengths less than 0.3µm are completely absorbed by ozone in the upper atmosphere. Photographic 0.3 to 0.4 µm Transmitted through the atmosphere. Detectable with film and photo- UV band detectors, but atmospheric scattering is severe. Visible 0.4 to 0.7 µm Imaged with film and photo-detectors. Includes the reflected energy peak of earth at 0.5µm. Infrared 0.7 to 100 µm Interaction with matter varies with wavelength. Atmospheric transmission windows are separated by absorption bands. Reflected IR 0.7 to 3.0 µm Reflected solar radiation that contains no information about thermal band properties of materials. The band from 0.7 to 0.9µm is detectable with film and is called the photographic IR band. Thermal IR 3 to 5 µm Principal atmospheric windows in the thermal region. Images at band 8 to 14µm these wavelengths are acquired by optical-mechanical scanners and special videocon systems, but not by film. Microwave 0.1 to 30cm Longer wavelengths can penetrate clouds, fog, and rain. Images may be acquired in the active or passive mode. Radar 0.1 to 30 cm Active form of microwave remote sensing. Radar images are acquired at various wavelength bands. Radio >30 cm Longest wavelength portion of the electro-magnetic spectrum. Some classified radar with very long wavelength operate in this region. Remote Sensing - Introduction

• Makes use of sensors that detect the reflected or emitted electro-magnetic radiation from natural sources, most notably the sun. • Due to its surface temperature of 5800K, the sun emits most of its energy in the visible part of the spectrum. • The earth with a surface temperature of 300K emits most of its energy in the thermal part of the spectrum. Remote Sensing - Introduction

Spec pectra ral l em emiss ssion, on, atmosp mospher eric tr transmi smitta ttanc nce and se sensor nsor se sensi nsitivity Figure (3a) Energy Source Figure (3b) Atmospheric Transmittance Thermal Scanners Figure (3c) Common Remote Sensing Systems Remote Sensing - Introduction

Atmospheric Tran At eric Transmit ittance Remote Sensing - Introduction

In Interact eractio ion bet between ween E EMR an R and d surfaces rfaces Remote Sensing - Introduction

Spect ectral Ref ral Reflect lectan ance C ce Curv rves es Remote Sensing - Introduction

Vegetat Veget atio ion reflect reflectan ance cu ce curv rves es Water Chlorophyll absorption absorption Remote Sensing - Introduction

Mineral Ref eral Reflect lectan ance cu ce curv rves es Remote Sensing - Introduction

Remote ote Se Sensi nsing S Syste ystems DATA ACQUISITION DATA ANALYSIS Reference data Pictorial Visual Numerical Quantitative Users Sources of energy Sensor systems Data products Interpretation Information procedures products Propagation through atmosphere Re-transmission through atmosphere Reflection on surface features Remote Sensing - Introduction

Plat atfo form rms Platform Altitude Observation Remarks geostationary satellite 36,000km fixed point observation GMS circular orbit satellite 500km - regular observation LANDSAT, SPOT, (earth observation) 1,000km MOS, etc space shuttle 240km - 350km irregular observations radio - sound 100m - 100km various investigations (meteorological, etc) high altitude jet-plane 10km -12km reconnaissance, wide area investigations low or mid altitude plane 500m - 8,000m various aero investigation surveys helicopter 100m- 2,000m various aero investigation surveys radio-controlled plane below 500m various aero investigation surveys aeroplane, hang-plane 50 - 500m various aero investigation surveys hangglider hang-balloon 800m - various investigations cable 10 - 40m archaeological investigations crane car 5 - 50m close range surveys ground measurement 0 - 30m ground truth cherry picker car Remote Sensing - Introduction

Eart arth O Observ ervatio ion S Satellit llite O e Orbits GROUND TRACK ALTITUDE = 705 KM (Nominal) INCLINATION = 98.2 O Equator crossing: 9:45am (Local time) DIRECTION OF TRAVEL ORBIT PERIOD = 98.9 MINUTES Remote Sensing - Introduction

Eart arth O Observ ervatio ion S Satellit llite O e Orbits / / 2 2 Remote Sensing - Introduction

Se Sensor nsors A sensor or ‘remote sensor’ is a device to detect the electro-magnetic radiation reflected or emitted from an object. Cameras or scanners are examples of remote sensing-sensors. Remote Sensing - Introduction

Sensors: S Solid S lid Stat ate S e Scan canners ers Remote Sensing - Introduction

Sensors: O Opto-Mech -Mechan anical S ical Scan canner Remote Sensing - Introduction