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

Remote Sensing - Introduction

GROUND TRUTH

Platforms with Sensor on board

GMS

(Geostationary Satellite)

LOW&MIDDLE ALTITUDE AIRPLANE LANDSAT, MOS, SPOT SPACE SHUTTLE HIGH ALTITUDE JETPLANE

emission reflection atmosphere

• bject

Illumination

Remote Sensing - Introduction

Conte

• ntents -

nts - Intr ntrod

• duc

ucti tion to R

• n 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

• n of R

Remote

• te 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.

Earth from Space

Generally, Remote sensing refers to the activities of recording/ observing/ perceiving (sensing) objects or events at far away (remote) places.

Remote Sensing - Introduction

How does Remote Sensing Work?

The characteristics of an object can be determined, using reflected or emitted electro- magnetic radiation, from the

• bject. Each object has a unique

and different characteristics of reflection or emission if the type

• f object or the environmental

condition is different. . 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.

Remote Sensing - Introduction

Prin inciples ples o

• f 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
• ther 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

λ (wave length) electric field magnetic field travelling direction

Remote Sensing - Introduction

Microwave bands W V O Ka K Ku X C S L P Ultra Violet Near Infra-red Short Wave Infra-red Inter- mediate Infra-red Thermal Infra-red v I

• l

e t b l u e g r e e n y e l l

• w
• r

a n g e r e d wavelength (µm) 0.4 0.6 0.8 1 5 7 10 0.3 (cm) 1 3 10 30 100 Wavelength: 0.1nm 10nm 1µm 100µm 10mm 1m 100m 10km

γ -ray X-ray UV Vis. Infrared EHF SHF UHF VHF MF LF VLF

The Electro-Magnetic Spectrum

Microwaves Radio waves Visible Light

Remote Sensing - Introduction

Charact aracter eris istics cs o

• f 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

• zone in the upper atmosphere.

Photographic UV band 0.3 to 0.4 µm Transmitted through the atmosphere. Detectable with film and photo- 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 band 0.7 to 3.0 µm Reflected solar radiation that contains no information about thermal properties of materials. The band from 0.7 to 0.9µm is detectable with film and is called the photographic IR band. Thermal IR band 3 to 5 µm 8 to 14µm Principal atmospheric windows in the thermal region. Images at 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

Figure (3c) Common Remote Sensing Systems Figure (3b) Atmospheric Transmittance Figure (3a) Energy Source

Thermal Scanners

Spec pectra ral l em emiss ssion,

• n, atmosp

mospher eric tr transmi smitta ttanc nce and se sensor nsor se sensi nsitivity

Remote Sensing - Introduction

At Atmospheric Tran 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

Chlorophyll absorption Water absorption

Veget Vegetat atio ion reflect reflectan ance cu ce curv rves es

Remote Sensing - Introduction

Mineral Ref eral Reflect lectan ance cu ce curv rves es

Remote Sensing - Introduction Visual Quantitative Users Sensor systems Data products Interpretation procedures Information products Reference data Pictorial Numerical

DATA ACQUISITION DATA ANALYSIS

Re-transmission through atmosphere

Remote

• te Se

Sensi nsing S Syste ystems

Sources of energy Propagation through atmosphere Reflection on surface features

Remote Sensing - Introduction

Platform Altitude Observation Remarks geostationary satellite 36,000km fixed point observation GMS circular orbit satellite (earth observation) 500km - 1,000km regular observation LANDSAT, SPOT, 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 car 0 - 30m ground truth cherry picker

Plat atfo form rms

Remote Sensing - Introduction

Equator crossing: 9:45am (Local time) ORBIT PERIOD = 98.9 MINUTES GROUND TRACK INCLINATION = 98.2O DIRECTION OF TRAVEL ALTITUDE = 705 KM (Nominal)

Eart arth O Observ ervatio ion S Satellit llite O e Orbits

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

In general, resolution is defined as the ability of an entire remote-sensing system, including lens, antennae, display, exposure, processing, and other factors, to render a sharply-defined image. Resolution of a remote- sensing system is of different types. (1) Spectral Resolution (2) Radiometric Resolution (3) Spatial Resolution (4) Temporal Resolution

Charact aracter eris istics cs o

• f RS

RS s system ems: R Resolu lution

Remote Sensing - Introduction

Spect ectral Res ral Resolution

Incoming light (mix of different wavelengths) Prism or Spectrometer Detectors

Remote Sensing - Introduction

Spect ectral Res ral Resolution / 2 / 2

coarse spectral resolution: only 1 value, same for soil and turbid water finer spectral resolution: 3 values, each is different for soil / water

Remote Sensing - Introduction

0.40 0.50 0.60 0.70 0.80 0.90 1.00 1.10 2.10 3.10 4.20 6.20 8.20 10.20 12.20

SPOT Pan SPOT XS Landsat TM NOAA AVHRR IRS LISS IRS WiFS ADEOS AVNIR

Spect ectral res ral resolution o

• f s

some RS RS system ems

Remote Sensing - Introduction

Spect pectral ral B Band R and Range (µm ge (µm) us used i ed in T Them hematic Mapp Mapper (T er (TM) o M) onboa nboard rd Lands andsat' at's 4 and 5 s 4 and 5 sens ensor s

• r system

em and th and thei eir pote r potenti tial al appl application

Band Number Band Range (µm) Potential applications 1 0.45 to 0.52 coastal water mapping; soil/vegetation differentiation; deciduous/coniferous differentiation (sensitive to chlorophyll concentration); etc. 2 0.52 to 0.62 green reflectance by healthy vegetation; etc. 3 0.63 to 0.69 chlorophyll absorption for plant species differentiation; 4 0.78 to 0.90 bio-mass surveys; water body delineation; 5 1.55 to 1.75 vegetation moisture measurement; snow/cloud differentiation; 6 10.4 to 12.5 plant heat stress management; other thermal mapping; soil moisture discrimination; 7 2.08 to 2.35 hydrothermal mapping; discrimination of mineral and rock types;

Remote Sensing - Introduction

Spectral Band Range (µm) used in Advance Very High Resolution Radiometer (AVHRR) sensor onboard NOAA Satellite system and their potential application.

CHANNEL WAVE LENGTH) USES NUMBER (µm)

CHANNEL 1 0.58 - 0.68 cloud delineation, weather snow and ice mapping and monitoring, etc. CHANNEL 2 0.73 - 1.1 surface water delineation, vegetation and agriculture assessment, range surveys, etc. CHANNEL 3 3.53- 3.93 land/water distinction, sea surface temperature, hot spot detection (forest fires and volcanic activity),etc. CHANNEL 4 10.3 - 11.3 day/night cloud mapping, sea and land surface temperature, soil moisture, volcanic eruption, etc. CHANNEL 5 11.5 12.5 sea surface temperature measurement, soil moisture, weather, etc.

Remote Sensing - Introduction

Mu Mult ltis ispect pectral ral im images ages: L : Landsat TM

TM6 ( (10. 0.4 - 4 - 12 12.5)

Remote Sensing - Introduction

Remote Sensing - Introduction

Sp Spatial r resol

• luti

ution / 2

• n / 2

SPOT Pan (10m) Landsat TM (30m) IRS WiFS (188m) NOAA AVHRR (1.1km) Landsat MSS (80m)

SPOT XS (20m) IRS Pan (6m) KVR (2m)

Remote Sensing - Introduction

SATELLITE SYSTEM SOME OPTICAL SENSOR SYSTEM LANDSAT 4/5 MSS LANDSAT 4/5 TM SPOT XS NOAA AVHRR MOS MESSR JERS OPS VINR and SWIR ADEOS AVNIR IRS-1C LISS-III IRS-1C WiFS Spatial Resolution 80 m 30 m 20 m 1.1 km (LAC) 50 m 18 m X 24 m 16 m 24 m 188 m (200 m) Off-nadir viewing (side-look) capability for the (PAN) Panchromatic mode for stereo image data acquisition) SPOT PAN (10m resolution) 0.51- 0.73 µm 3 days revisit capability JERS OPS VINR (18m X 24m) Bands 3 & 4 0.76 - 0.86 µm ADEOS AVNIR PAN (8 m Resolution) 0.52 - 0.72 µm IRS-1C PAN (6 m resolution) (70 km swath width) 0.50 - 0.70 µm (6-bit)

Spa Spatia ial R l Reso solutio tion

Remote Sensing - Introduction

Sp Spatial r resol

• luti

ution:

• n: T

TM a and SP SPOT OT Pa Pan

Remote Sensing - Introduction SATELLITE LANDSAT LANDSAT SPOT NOAA MOS JERS ADEOS IRS-1C IRS-1C SYSTEM MSS TM XS AVHRR MESSR OPS AVNIR LISS-III WiFS VINR AND SWIR Revisit Cycle 16 16 20 (nadir) 1 image/day 17 44 41 (nadir) 24 (nadir) (in days)

Temp mpor

• ral r

resol

• luti

ution

• n

Sensor Satellite Level (bit) Descriptions

MSS LANDSAT 6 8 bits data after radiometric correction TM LANDSAT 8 HRV (XS) SPOT 8 HRV (PA) SPOT 6 AVHRR NOAA 10 both 10 and 16 bits’ data are available at distribution SAR JERS-1 3 real 3 bits, imaginary 3 bits

Quantization level of remote-sensing data

Remote Sensing - Introduction

The remote sensing satellites are equipped with sensors looking down to the earth. They are the "eyes in the sky" constantly observing the earth as they move around the earth.

Remote Sensing Satellite

Remote Sensing Satellite

Remote Sensing satellite images gives a synoptic (bird’s eye) view of any places of the Earth surface, which helps to study, map, and monitor the Earth’s surface at local and/or regional/global scales. It is cost effective and gives better spatial coverage as compared to ground sampling.

Remote Sensing - Introduction

There are several remote sensing satellite series in operation. Different satellite systems have different characteristics, e.g. resolutions, number of bands, and have their own importance for different application.

Satellite Systems Spatial Resolution Type Number of Bands Launched by LANDSAT-ETM+ LANDSAT-TM LANDSAT-MSS SPOT-XS SPOT-PAN IRS-1C PAN IRS-LISS-III IRS-WiFS Cosmos -KVR1000 IKONOS IKONOS ADEOS-AVNIR M NOAA AVHRR MOS MESSR 15,30,50 30m 80m 20m 10m 6m 24m 188m 2m 1m 4m 16m 1.1Km 50m Multi-spectral Multi-spectral Multi-spectral Multi-spectral Panchromatic Panchromatic Multi-spectral Multi-spectral Panchromatic Panchromatic Multi-spectral Multi-spectral Multi-spectral Multi-spectral 8 7 4 3 1 1 4 2 1 1 4 4 5 4 USA USA USA France, Sweden France, Sweden India India India Russia/USA Canada Canada Japan USA Japan

Types of Remote Sensing Images

Remote Sensing - Introduction

Remote Sensing - Introduction

SATELLITE SYSTEM SOME OPTICAL SENSOR SYSTEM LANDSAT 4/5 MSS LANDSAT4/5 TM SPOT XS NOAA AVHRR MOS MESSR JERS OPS VINR and SWIR ADEOS AVNIR IRS-1C LISS-III IRS-1C WiFS Spectral Resolution (Number of Bands) Four Seven Three Five Four Seven Four Four Two Spectral ranges (wave-length portion of EMR) in µm (micrometers) Blue 0.45 - 0.52 0.40 - 0.50 Green 0.50 - 0.60 0.53 - 0.61 0.50 - 0.59 0.51 - 0.59 0.52 - 0.60 0.52 - 0.62 0.52 - 0.59 Red 0.60 - 0.70 0.62 - 0.69 0.62 - 0.68 0.58 - 0.68 0.61 - 0.69 0.63 - 0.69 0.62 - 0.72 0.62 - 0.68 0.62 - 0.68 NIR 0.70 - 0.80 0.78 - 0.90 0.78 - 0.88 0.73 - 1.10 0.72 - 0.82 0.76 - 0.86 0.77 - 0.86 0.77 - 0.86 NIR 0.80 - 1.10 0.80 - 1.10 0.82 - 0.92 IIR 1.57 - 1.78 1.60 - 1.71 1.55 - 1.75 IIR 2.10 - 2.35 3.55 - 3.93 2.01 - 2.12 IIR (MIR) 2.13 - 2.15 IIR (MIR) 2.27 - 2.40 ThIR 10.45 - 11.66 10.3 - 11.2 FIR 11.5-12.5

Remote Sensing - Introduction

Remote sensing images are normally in the form of digital images. Image processing techniques are applied to enhance the image to help visual interpretation, information extraction and to correct or restore the image if the image has been subjected to geometric distortion, blurring

• r degradation by other factors. There are many image analysis techniques

available and the methods used depending upon the requirements of the specific problem concerned.

Remote Sensing Images

Satellite Image of Kathmandu