Intro to RS and GIS by mndp poonia

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A Presentation By : Mandeep MSc. Final (Env. Scs.)

Contents of Presentation

1. Introduction to Satellites and their types 2. India’s Earth Observation Programme 3. Brief Introduction to Foreign Space Tech. 4. Trends in Tech. 5. Geo-Informatics : a) RS b) GIS c) GPS d) ICT 6. Photo-Interpretation 7. Apps. of RS & GIS in Various Fields 8. Apps. of RS & GIS in Environmental Management

1. Satellites and their types

What is Satellite ?

Heavenly or artificial body revolving round a planet e.g. Heavenly Body-Moon Artificial Body-Man made Satellite Types: 1. Geostationary Satellite (communication) 2. Polar Sun Synchronous Satellite (Remote Sensing)

Geostationary Satellite

Sun-synchronous Satellite

Satellite Orbits

Sun-synchronous satellite

TYPES OF SATELLITES Astronomical satellites : Used for study of distant celestial objects and outer space. Communications satellites : For communications/ Broadcasting Miniaturized satellites : Low weights and small sizes.

Minisatellite : 500–100 kg Microsatellite : 100-10 kg Nanosatellite : >10 kg Navigational satellites : Uses for radio time signals transmitted to enable mobile receivers on the ground to determine their exact location in real time, i.e. GPS, GLONASS, GALILEO, COMPASS Reconnaissance satellites : Earth observation satellite or communications satellite deployed for military or intelligence applications. Very little is known about the full power of these satellites Earth observation satellites : Satellites intended for non-military uses such as environmental monitoring, meteorology, map making etc. Weather satellites : Used to monitor Earth's weather and climate Anti-satellites weapons : Satellites that are designed to destroy enemy warheads, satellites, other space assets. Space stations : Orbital structures that are designed for human beings to live on in outer space.

2. India’s Earth Observation Programme

Dr. Vikram Sarabhai (1919-1971)

The Architect of Indian Space Programme

Capsule of Wisdom:

“He who can listen to music in the midst of noise can achieve great things”

Indian Space Programme – the Initial Days

World Class

Launch Facilities

Indian Space Programme – the Initial Days to Today

2001: Successful flight test of GSLV

2002: Launch of METSAT (renamed Kalpana) by PSLV.

2003: Launch of RESOURCESAT-1, Launch of third generation INSAT-3A

2004: Successful Ist operational flight of GSLV. EDUSAT launched

2005: CARTOSAT-1 launched

2007: CARTOSAT-2 launched

2008: Launch of CARTOSAT-2A along with 10 satellites onboard PSLV C-9

• Chandrayaan-1 Launched

2009: Oceansat-2 and Risat-2 launched.

2010: Cartosat-2B launched

2011: Resourcesat-II launched, Megha-Tropics Launched

2012: RISAT-I launched

• 2013 : Mangalyaan Launched, IRNSS-1A Launched, GSAT-7 with cryogenic engine launched

• 2014 : IRNSS-1B Launched, SPOT-7 launched, Mangalyaan inserted in Mars Orbit

Recent satellites launched

2013(25 Feb) SARAL 2013( 1 July) IRNSS-1A 2013(26 July) INSAT-3D 2013(30 August) GSAT-7 2013( 5 Nov) MOM(Mars Orbiter Mission) 2014 (5 Jan) GSAT-14(capacity of Extended C and Ku-band) 2014 (4 April) IRNSS-1B 2014(10 Nov) IRNSS-1C 2014(7 Dec) GSAT- 16(48 transponder) 2015 (28 March) IRNSS-1CD

1. Indian Space Research Organization (ISRO): Bangalore

2. Space Applications Centre (SAC) : Ahmedabad 3. Vikram Sarabhai Space Centre (VSSC):

Thiruvananthapuram 4. National Remote Sensing Agency (NRSA):

Hyderabad

5. Indian Institute of Remote Sensing (IIRS): Dehradun

6. Satish Dhawan Launching Centre : Sriharikota 7. INSAT Master Control Facility: Hasan 8. North-Estern Space Application Centre (NE-SAC): Shillong 8. Regional Remote Sensing Centres (RRSCs) Dehradun Jodhpur Nagpur Bangalore Kharagpur

LAUNCH VEHICLE FAMILY

SOUNDING ROCKET-1972

SLV,17T,40Kg,LEO-1979

ASLV,39T,150Kg.LEO-1987

PSLV,275T,1000Kg,POLAR-1993

GSLV,402T,2500Kg,GTO-2001

INSAT & GSAT INSAT

The Indian National SATellite system is a series of multipurpose geo-stationary satellites launched by ISRO to satify the telecommunications, broadcasting, meteorology, search and rescue operations.

Commissioned in 1983 is the largest domestic communication system in the Asia pacific region.

It is a joint venture of the DOS, Deptt. Of telecomm., IMD, AIR, and Doordarsan.

GSAT

The GSAT (Geosynchronous Satellites) satellites are india’s indigenously developed technologies of comm. Satellites, used for digital audio, data and video broadcasting.

As of Aug. 2015, 12 GSAT Satellites have been launched by ISRO.

Recently on Aug 27 ,2015 GSLV successfully launches India’s latest communication satellite GSAT-6

Towards Thematic Satellites : Recent Emphasis

OCM & MSMR

Resourcesat-1

Metsat-1

Edusat

Oceansat-1

Cartosat-1

INSAT – 4A

AWiFS, LISS 3

& LISS 4

Fore & AFT PAN 6 Ku &

6 Ext C

VHRR & DRT

12 C &

12 Ku High resolution & Multi-spectral

Along-track Stereo & DEM

Multiband & hyperspectral Towards mesoscale weather

modeling

DTH: Reaching the homes

Virtual Schools & Universities

AWS DWR

Addressing

Societal

Needs

RISAT-1

C-band SAR; 3-50 m

Multi-Pol; Multi mode

Launch : PSLV-C5, 17 Oct. 2003/ 20 May, 2011

APPLICATIONS POTENTIAL

• Natural resources census

• Improved crop discrimination

• Vegetation dynamics

• Crop yield

• Disaster management support

• Forestry and biodiversity etc.

Mission Life : 5 Yrs

Mass of S/C : 1350 kg (at Lift-off)

Orbit : 817 km; Sun-synchronous

Payloads : LISS- 3, LISS- 4 & AWiFS

Spatial Res. : 23.5m 5.8 m 56 m

Repetitivity : 24 days for LISS-3

5 days for AWiFS

Revisit : 5 days for LISS-4

(with 26 Deg. Tilt)

Resourcesat – I &II

• 2.5 m resolution, 30 Km Swath

• Stereo mission; +26° / -5°

forward/ Aft view

• Revisit : 5 days

• Along Track Stereo viewing -

first of its kind in the world

Cartosat-1&2

• Large Scale Cartographic maps

• Cadastral level Thematic maps

• National Digital Elevation Model

• Rural Development

• Urban infrastructure & utility planning

Launch : PSLV-C6: May 05, 2005

APPLICATIONS POTENTIAL

Trans Lunar

Injection

Mid Course Correction

GTO

ETO

Lunar Transfer

Trajectory

Initial Orbit

~ 1000 km

Lunar Insertion

Manoeuvre

Final Orbit

100 km Polar

ASTROSAT

Moon at Launch

To achieve 100 x 100 km Lunar Polar Orbit.

PSLV to inject 1050 kg in GTO of 240 x 36000 km.

Lunar Orbital mass of 523 kg with 2 year life time.

Scientific payload 55 kg.

Expanding the scientific knowledge about the Moon; Upgrading our technological

capability; Providing challenging opportunities for planetary research

Chandrayaan – 1:

Indian Observatory

in Space

Beyond the Earth…

Multiwavelength Observatory

Payloads

TMC: Terrain Mapping

Camera (PAN; Stereo;

5m; 40km)

HySI: Hyperspectral

imager (400-900 nm;

15nm; 80m; 40km)

LLRI: Lunar Laser

Ranging Instrument (10

height res.)

LEX: Low Energy X-

ray spectrometer

(10km footprint)

HEX: High Energy X-

ray spectrometer

(20km footprint) to

study radioactive

elemetns.

1. Atmospheric studies:

i. Lyman-Alpha Photometer (LAP): a photometer that measures the ratio of deuterium and hydrogen in the upper atmosphere which will help in estimating the amount of water loss to outer space. ii. Methane Sensor for Mars (MSM): It will measure methane in the atmosphere of Mars, if any, and map its sources. 2. Surface imaging studies i. Thermal Infrared Imaging Spectrometer (TIS) — will measure the temperature and emissivity of the Martian surface, allowing for the mapping of surface composition and mineralogy of Mars. ii. Mars Color Camera (MCC) — will provide images in the visual spectrum, providing context for the other instruments.

Future Indian EO Missions

RESEOURCESAT-3: Increased resolution and more spectral bands:

Sensor : AWiFS 25 m reolution, 600 km swath. LISS-III-WS, 23.5 m resolution, 2 additional bands, Wide Swath LISS-IV at 5.8m with 1 additional band, 25km swath Addition of new sensors with 25km swath: LISS-V (PAN) at 2.5m resolution Hyperspectral at 25m resolution (~200 Bands) 5 day revisit cycle

RESEOURCESAT-4: Addition of new sensors with 12.5 km swath

Sensor: LISS-IVn at 2.5m, 3-4 bands, 5 day revisit LISS-Vn at 1.25m PAN, 5 day revisit HISn at 12.5m, 200 bands, 5 day revisit

CARTOSAT-3: Increased resolution and more spectral bands:

Sensors: PAN at 0.5m resolution MSI at 2-4m, 4 bands HSI at 8m, ~200 bands Swath at 8-10km

OCEANSAT-3: Sensor : Thermal IR Sensor, 12 channel Ocean Color Monitor, Scatterometer and Passive Microwave Radiometer. Uses : Potential Fishing Zones. Ocean biology and Sea state applications

3. Brief introduction to Foreign Space Tech.

International Space Agencies

India ISRO USA NASA Russia ROSCOSMOS Japan JAXA France CNES China CNSA EU ESA Germany DLR

Major Foreign R. S. satellites

Satellite Sp. Resolution Country (meters) NOAA 1100 USA Landsat (5,7,8) USA Multispectral Scanner (MSS) 80 Thematic Mapper (TM) 30 Enhanced TM (ETM) 20 SPOT 10/20 French RADARSAT 30-50 Canada (Microwave) IKONOS 1.0/4.0 Space Imagine, USA (Now GeoEye) Quick Bird 0.6/2.5 Digital Globe, USA Word View-I 0.5 m PAN Digital Globe, USA (2007) stereo GeoEye-1 0.4 m PAN GeoEye, USA 2008 1.6 m Mxl Word View-II 0.5 m PAN Digital Globe, USA (2009) 1.84 m Mxl Word View-III 0.31 m PAN Digital Globe, USA (2014) 1.24 m Mxl

3.70 m SWIR

4. Trends in Technology

Aerial

Photography

Satellite

Remote

Sensing

Image

Interpretation

Satellite

Remote Sensing

& Digital Image

Processing

Satellite

Remote Sensing

& Geographic

Information

System (GIS)

Satellite

Remote

Sensing

GIS & Global

Positioning

System

Satellite

Remote

Sensing

GIS, Global

Position System,

Web

communication

& Virtual World

1975-1990 1990-1995 1995-2000 2000-20005 2005 - Beyond 1960-1975

Trends in Technology

Topographic

Mapping

Thematic

Mapping

Widening of

Thematic

Disciplines

Integration of

Thematic

Information

Spatial

Modelling

Decision

Support

System

Geosciences

Forestry

Soils

Water

Resources

Oceanography

Marine Science

Agriculture

Fisheries

Biodiversity

Drinking

Water

Geomorphology

…...-1975 1970-1980 1980-1990 1990-1995 1990- …. Future trends

Biodiversity

Prioritisation

Modeling

Landslide

Hazard

Zonation

Modeling

Infrastructure

Management

Natural

Resource

Management

Strategic

Planning

Land

Management

and Reform

Trends in Application

5. Geo-Informatics

EOS AM-1 in orbit

GEO-INFORMATICS RS

GIS

GPS

Geographic Information System (GIS), Remote Sensing (RS), Global Position System (GPS) and Information & Communication Technology (ICT) which help in acquiring and analyzing information about the Earth and its resources in spatial format

ICT

• ‘Remote’ means far away and ‘Sensing’ means believing or observing or acquiring some information.

• Remote sensing means acquiring information of things from a distance.

• Three out of five senses uses RS : 1. EYE (sense of sight) 2. EAR(sense of hearing) 3. NOSE(sense of smell) • While other two require physical contact 1. Sense of Touch 2. Sense of taste

Remote Sensing is the Science(and to some extant, art) of acquiring information about the earth’s surface without actually being in contact with it.

This is done by sensing and recording reflected or emitted energy and processing, analysing,and applying that information.

Remote Sensing(RS)

Receiving station processing Archiving

Distribution

PRINCIPLE OF REMOTE SENSING

PRINCIPLE OF REMOTE SENSING

A. Energy Source or Illumination B. Radiation and the Atmosphere C. Interaction with the Target D. Recording of Energy by the Sensor E. Transmission, Reception and Processing F. Interpretation and Analysis G. Application

• Active sensor

– Throws energy on the target object & senses the reflected energy

• Camera with flash

• RADAR

• Passive sensor

– No personal source of energy (Sun is the only source); senses energy reflected/ emitted by the target

• Camera without flash

• Human eye, ear, nose

Active and Passive Remote Sensing

WAVE CONCEPT OF EMR

C = ν λ

Electromagnetic energy forms the basic source for remote sensing observations. Sun is the universal source of electromagnetic energy.

The electromagnetic spectrum is the form of arrangement of electromagnetic energy either in the form of wavelength or in frequency.

The basic relation is

E=MC2

C=υ λ

υ= Frequency; λ = Wavelength ; C = Velocity of Light

E= Energy; M = Mass of Particle

ELECTOMAGNETIC SPECTRUM

Violet: 0.400 - 0.446 µm Primary Colours: Blue: 0.446 - 0.500 µm Red, Green, Blue Green: 0.500 - 0.578 µm Yellow: 0.578 - 0.592 µm Orange: 0.592 - 0.620 µm Red: 0.620 - 0.700 µm

• Black Body : that absorbs all incident

Radiations

• White Body : that Reflects all

Incident Radiations

• EARTH acts as a Gray Body

Thermal Sensing

Reality is the perceived Truth

Visible Sensing

Radiations is very sensitive to temp. of Body

Particles and gases in the atmosphere can affect the incoming light and radiation. These effects are caused by

1. Scattering Rayleigh scattering occurs when particles are very small compared to the

wavelength of the radiation. These could be particles such as small specks of dust or nitrogen and oxygen molecules.

Mie scattering occurs when the particles are just about the same size as the wavelength of the radiation. Dust, pollen, smoke and water vapour are common causes of Mie scattering which tends to affect longer wavelengths than those affected by Rayleigh scattering.

Nonselective scattering. This occurs when the particles are much larger than the wavelength of the radiation. Water droplets and large dust particles can cause this type of scattering.

2. Absorption Ozone, Carbon dioxide, and Water Vapour are the three main atmospheric

constituents which absorb radiation. 3. Reflection: Some radiations are reflected back to atmosphere from clouds, aerosoles and

water droplets.

INTERACTION WITH ATMOSPHERE

Energy Interaction Mechanism

Interaction with the Target

Specular Reflection Diffused Reflection

SPECTRAL REFLECTANCE OF VARIOUS OBJECTS

Atmospheric Windows

______________________________________ λ (µm) Spectral region ______________________________________ 0.3-1.3 VIS-NIR 1.5-1.8 MIR 2.0-2.6 3.0-3.6 4.2-5.0

7.0-15.0 TIR __________________________________________

ATMOSPHERIC WINDOWS

Components of Remote Sensing

• Platform

– The vehicle/device on which sensors are mounted

• Sensor System

– The device which senses the energy reflected/emitted by the target object

• Data Products

– Information received from the sensor Packaged as per user requirement

PLATFORMS

• Remote sensing is essentially studying

interaction of electro-magnetic radiation

with different objects – land, water,

atmosphere, etc.

• Understanding properties of EM radiation

under various conditions is fundamental

to understanding of remote sensing,

both from technology and application

point of view.

Data Representation

Data Products

• Satellite data products are available from the data suppliers i.e. NRSC in India

• Data is available based upon the user requirements

• Type

– Digital data for processing by Computer

– Photographic prints for visual interpretation

i.e. Hardcopies, Negatives, Dia-positives

Characteristics of Data Products

• Area Covered

• Date & Time of acquisition

• Level of Processing

– Raw

– Corrected for Radiometric errors

• Line drop outs, sensor malfunctions

– Corrected for Geometric errors

– Special Products (Merged/enhanced/image maps)

Interpretation of Remotely Sensed Information

• Concept of signature – A combination of characteristics of the objects by

which we can identify it on remote sensing data

– The characteristics are manifested in terms of shape, size, tone, texture (frequency of tonal change, pattern (spatial arrangement of objects), context / association etc on the image

– Based on our prior knowledge – identify the characteristics to be used as signature

– Associate signature with objects : develop Interpretation key

Panchromatic Image: is the one that captures the image across large part of the electromagnetic spectrum. It is a single band image in gray scale. Multi-spectral Image: is one that captures image data at specific frequencies across the electromagnetic spectrum. Multi-band (>3 bands) image data is in gray scale and any three bands can be used to create a coloured image. Hyper-spectral Image: is one that captures image data at very small frequency intervals across the electromagnetic spectrum. It contains data in numerous bands.

PREPARATION OF TCC AND FCC

EM bands Assigned

Colour

Blue Blue

Green Green TCC

Red Red

NIR

Blue Blue

Green Green FCC

Red Red

NIR

True and false Color Photography

Resolution

Resolution is defined as the ability of the system to provide the information at the smallest discretely separable quantity, in terms of area (spatial), wavelength band of EMR (spectral), radiation quantity (radio-metric) and time (temporal)

PIXEL and Resolution • The PIXEL (a word invented from “picture element”) is

the basic unit of programmable color on a computer display or computer image.

• The following slide has the same photo at three resolutions.

• Remember this doesn’t change the size in terms of the number of pixels which is the true measure of resolution, it just changes the physical size of the photo.

• I am assuming a screen or projector size of 800 x 600 pixels.

• The image in the top third of the slide is the correct size for this application, It’s 800 pixels wide by 200 pixels high.

• The middle third, the number of pixels has been reduced by half in both dimensions, to 400 pixels by 100 pixels.

• The bottom third, the number of pixels has been reduced again by half in both dimensions, to 200 pixels by 50 pixels.

• The top picture which matches the resolution of the output device exactly gives the best image.

• On the screen their resolution in dots per inch is somewhat irrelevant, since that depends on the size of the monitor or projected image. As long as I get the number of pixels right, I’ll have the best image quality available.

2.5 x 10 inches at

80 dots per inch

2.5 x 10 inches at 40 dots per inch

2.5 x 10 inches at

20 dots per inch

Spatial resolution Scanner’s spatial resolution is the smallest ground segment sensed at any instant. It is also called ground resolution element or pixel.

LISS III G, R, IR 23.5 m MIR 70.5 m LISS IV G, R, IR 5.8 m

WiFS R, IR 188 m AWiFS G, R, IR 58 m

Cartosat-I PAN 2.5 m Cartosat-II PAN 1.0 m

Spectral resolution Sampling the spatially segmented image in different spectral intervals, thereby allowing the spectral Irradiance of the image to be determined. m

PAN 0.50 - 0.75 LISS III Band 2 0.52 - 0.59 Band 3 0.62 - 0.68 Band 4 0.77 - 0.86 Band 5 1.55 - 1.70 Thermal Band 1 0.45-0.52 Mapper (TM) Band 2 0.52-0.60 Band 3 0.63-0.69 Band 4 0.76-0.90 Band 5 1.55-1.75 Band 6 10.40-12.50 Band 7 2.08-2.35 Enhanced TM Band 8 0.52-0.90 (in addition to TM)

Hyper-spectral Imaging MODIS 30 bands with 250 m-1 km spatial resolution,1900-2300 swath Hyperion 242 bands of 11 nm each in 400-2500 nm range and 30 m spatial resolution, 7.5 km swath

Radiometric resolution The number of different intensities of radiation the sensor is able to distinguish. Dividing the total range of the signal output of the sensor into a large number of just discriminable levels so as to be able to distinguish ground features differing only slightly in a radiance or reflectance. LISS III 7 bit / 128 levels (10 bit for R-II) AWiFS 10 bit / 1024 levels (12 bits for R-II) PAN 6 bit / 64 levels

Temporal resolution

Obtaining spatial and spectral data at certain time intervals. Temporal resolution is also called as the repetitivity of the satellite in case of satellites IRS 1A/1B 22 days IRS 1C/1D 24 days PAN 5 days

Advantages of Remote Sensing

• Synoptic View – Very large area at a glance

– Move mountains to your desktop

• Very Fast information acquisition – Timely & accurate information

• Repeated coverage

• Digital data amenable to computer processing

• Permanence of records

• Mapping of inaccessible areas

• Economical

to GIS : • The Geographic(al) information system consists

two different disciplines: geography and information system.

• Geography is the scientific study of geospatial pattern and process while information system refers to a system containing electronic records.

• The GIS is a computer- based information system used to digitally represent and analyse the geospatial data or geographic data

• Geographic Information System (GIS) is defined as an information system that is used to input , store, retrieve, manipulate, analyse, and output geographically referenced data or geospatial data, in order to support decision making for planning and management of land use, natural resources, environment, transportation, urban facilities, and other administrative records.

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Defining GIS

• A Powerful tool for solving real-world problems

A method to

visualize, manipulate, analyze, and display spatial data

Key Components of GIS

Computer System

Harware Software

Procedure

Users Data

GIS

Hardware, Software and Procedure For capture, storage, processing, Analysis, display, etc.

Maps, aerial photographs, Satellite images, statistic Tables, etc.

Design of standards, updating, Analysis and implementation

GPS- Global Positioning System

GPS is a satellite-based system, operated and

maintained by the U.S. Department of Defense (DoD),

that provides accurate location

and timing information to

people worldwide.

The system transmits radio

signals that can be used by GPS receivers to

calculate position, velocity and time

anywhere on earth, any time of

day or night, in any kind of

weather.

The NAVSTAR GPS concept was

developed in the early 1970's to meet

the U. S. military’s need for improved

navigation and positioning. The first Block I GPS satellite

was launched in 1978 and Full Operational

Capability (FOC) was achieved in 1994.

GPS Segments

The GPS consists of 3 segments:

1. Space

2. Control

3. User

Space Segment • The space segment is the satellite constellation,consisting

of 24 or more satellites.

• There are four satellites in each orbit plane

• The high altitude insures that satellite orbits are stable, precise and predictable, and that the satellites' motion through space is not affected by atmospheric drag.

• It also insures satellite coverage over large areas.

• GPS satellites orbit around the earth, in contrast to TV satellites which are in geostationary orbits (they rotate with the earth).

• The GPS satellites cross over any point on the earth approximately twice per day.

Satellite characteristics

24 satellites in 6 orbital planes. Satellites complete an orbit in approx. 12 hours.

Black = visible satellites, Red = not visible, Green = sight lines

Global Positioning System (GPS)

Satellite Signals

• The radio signals travel at the speed of light: 300,000 km per second.

• It takes 6/100ths of a second for a GPS satellite signal to reach earth.

• C/A code (Coarse Acquisition code) is available to civilians as the Standard Positioning Service (SPS).

• SPS now provides average horizontal accuracy of 7.8 meters 95% of the time and average vertical accuracy of <= 15 meters.

• The Precise Positioning Service (PPS), available only to the military (and other authorized users), provides higher accuracy via the P code.

Control Segment

The control segment is operated by the U.S. Department of Defense (DoD) which tracks and maintains the satellites. The Department of Transportation (DoT) now has management responsibility, along with DoD.

Control Segment

User Segment

The user segment consists of both military and civilian users. Military uses of GPS include navigation, reconnaissance, and missile guidance systems. Civilian use of GPS developed at the same time as military use, and has expanded far beyond anyone's original expectations.

Examples of civilian GPS applications include :

The user segment consists of receivers that provide positioning, velocity and precise timing to users worldwide.

Civilian applications of GPS exist in almost every field, from surveying to transportation to natural resource management to agriculture.

1) GPS on a helicopter to identify the location of victims in search and rescue operations

2) GPS on a tractor/combine linked to a yield monitor to generate yield maps (precision farming)

3) GPS used for aircraft navigation or to mark where rangeland weedshave been sprayed,

4) GPS used for recreational sailing navigation

5) Emergency services response system: a combined GPS/GIS system used to dispatch emergency vehicles and find the quickest route to a destination (GPS is also being used for pizza delivery systems

6) GPS to help a backpacker navigate in the woods.

How Does GPS Work?

GPS satellites are constantly transmitting signals that contain orbit data and timing information. Receivers pick up those signals and use the information tocompute positions.

Note:

Receivers don’t send signals back to satellites, contrary to what manypeople think. They are receivers not transceivers

How Does GPS Work? GPS receiver calculates its position by measuring the distance to satellites (satellite ranging).

3 Distance Measurements

Other Global Navigation Satellite Systems

Global Navigation Satellite System (GNSS) is the standard generic term for

satellite navigation systems that provide autonomous geo-spatial positioning

with global coverage. A GNSS allows small electronic receivers to determine

their location (longitude, latitude, and altitude) to within a few metres.

• Global Positioning System (GPS) of USA

• GLONASS of Russia

• GALILEO of EU (under development)

• IRNSS of India (under development)

• COMPASS of China (under development)

Global Navigation Satellite Systems

(GNSS)

• ICT (Information and communication technology –or technologies) is an umbrella term that includes any communication device or application, encompassing : radio, television, cellular phones, computer and network, hardware and software, satellite systems and so on, as well as the various services and applications associated with them, such as videoconferencing and distance learning.

• ICTs are spoken of in a particular context, such as ICTS in education, health care etc.

6. Photo-Interpretation

Introduction to Photo-Interpretation • Unlike a map, features on an aerial photograph or

image are not generalized or symbolized.

• Air photos record all visible features on the earth’s surface from an overhead perspective.

• Although the features are visible, they are not always easily identificable.

• “the process of studying and gathering the information required to identify the various cultural and natural features is called Photo-Interpretation”

• With careful interpretation, air photos are an excellent source of spatial data for studying the Earth’s Environment.

• Photographic interpretation is “the act of examining photographic images for the purpose of identifying objects and judging their significance”

• This mainly refers to its usage in military aerial reconnaissance using photographs taken from reconnaissance aircraft.

• The most basic principle is the elements of image interpretation which are :

1. Location 2. Size 3. Shape 4. Shadow 5. Tone/color 6. Texture 7. Pattern 8. Height /Depth 9. Site /Situation/Association 10. Time 11. Stereo perspective • These are routinely used when interpreting an aerial photo or

analyzing a photo- like image.

Elements of Photo-Interpretation

1. Location : There are two primary methods to obtain precise location in the form of coordinates –

(i) Survey in the field using traditional surveying techniques or GPS instruments.

(ii) Collect remotely sensed data of object, rectify the image and then extract the desired coordinate information.

2. Size : The size of an object is one of the most distinguishing characteristics and one of the more imp. Element of interpretation. Most commonly length, width and perimeter are measured. It is the measure of the surface area

(e.g. single-lane vs. multi-lane highways)

3. Shape : the form of an object on an air photo helps in identifying the object. Regular uniform shapes often indicate a human involvement.

4. Shadow : A Shadow provides information about the object’s height, shape, and orientation (e.g. tree species)

5. Tone / Color : The color chacs. of an object, relative to other objects in the photo, are used to identify the feature (e.g. sand has a bright tone, while water usually has a dark tone; tree species can be determined by the color of their leaves at certain times of the year.

6. Texture : The physical chacs. of an object will change the way they appear in the photo (e.g. calm water has a smooth texture; a forest canopy has a rough texture);

7. Pattern : similar to shape, the spatial arrangement of objects (e.g. row crops vs. pasture) is also useful to identify an object and its usage.

8. Height / Depth :

Height and Depth also known as “elevation” and “bathymetry”, is one of the most diagnostic elements of image interpretation. This is bcoz any object, such as a building or electric pole that rises above the local landscape will exhibit some sort of radial relief. Also, objects that exhibit this relief will cast a shadow that can provide info as to its height or elevation.

A good example of this would be buildings of any major city

9. Site /Situation /Association : Associating the presence of one object with another, or relating it to its environment, can help identify the objects (e.g. industrial buildings often have access to railway sidings; nuclear power plants are often located beside large bodies of water);

10. Time : temporal chacs. of a series of photographes can be helpful in determining the historical change of an area (e.g. looking at a series of photos of a city taken in different years can help in determining the growth of suburban neighbourhoods.

11. Stereo Perspective : watching an area in stereo, or 3D, is imp. For determining the topographical relief of an area, as well as the height of objects such as trees and building.

Stereoscopic imagery is the result of overlap, which is the amount by which one photograph includes an area covered by a neighbouring photograph.

7. Applications of Remote Sensing and GIS in various Fields

• Water Resources

• Geosciences

• Land Use / Land Cover & Urban Studies

• Agriculture & Soils Forestry

• Oceanography & Coastal Zone Studies

• Integrated Studies

• Disaster Management

Research & Development

Capacity building

Disaster Support Centre

Operational Services

Geo-informatics Applications

Panchayat

Planning

Watershed

Space-based Services for

Community Outreach

Tele-medicine

Training

Tele-education Weather Drinking Water

Information

Village Resources Centre (VRC)

Major Areas of Applications • LAND-COVER AND LAND-USE : Land cover and Land

Use change, Land Cover Mapping • AGRICULTURE : Crop Type Mapping, crop monitoring

and crop damage assessment. • FORESTORY : clear-cut mapping and Deforestation , Species identification and type, burn mapping. • GEOLOGY : structural mapping and terrain analysis,

lineament extraction, geologic unit mapping • GEOMORPHOLOGY : alluvial/fluvial(flowing

water)plain, eolian plain,weathering ,erosion,etc • URBAN APPS • HYDROLOGY : flood delineation and mapping, soil

moisture, ground water prospectus and recharge

• MAPPING

• OCEANS AND COASTAL MONITORING : ocean features, ocean color and phytoplankton conc., oil spill detection, sea surface height, sea surface roughness, ship routing, sea ice

• MONITORING OF ATMOSPHERIC CONSTITUENTS

IN SHORT WE CAN SAY THAT FROM EARTH SURFACE TO HIGH ABOVE IN THE SKY THERE ARE WIDE APPS. OF RS&GIS

Apps. of RS & GIS in Environmental Management

Environmental Monitoring : (i) Pollution Monitoring (ii) EIA (iii) Resource Monitoring (iv) Climate Change Environmental Mapping : I. Ground water and surface water II. Forest mapping III. Land use and Land cover IV. Mineral Resources V. Energy Resources VI. Water Resources VII. Wildlife VIII.Urban Mapping

Environmental Management : 1) Resource conservation and management : a) Biological Resource Management : i. Forest management ii. Wildlife Management iii. Management of Wetlands and fresh water ecosystems. (2) Physical Resource Management : • Watersheds • Rivers • Lakes • Soil conservation • Wasteland management (3) Energy Management

Weather Forecasting

Flood Mapping

Detection of Paleochannels.

Change Detection by comparing with past records

Landslide Monitoring etc.

In short , RS & GIS has huge applications in each and every field of environment.

NIGHT ARRIVES BETWEEN EUROPE & AFRICA

SANDSTORM LEAVING NORTH AFRICA TOWARDS THE ATLANTIC – CANARY ISLAND.

GIBRALTAR STRAITS

BLACK SEA

RED SEA

Resourcesat: AWiFS images

AWiFS Scene

Area South of Sirsa FCC (May, 02) (Rawatsar, Rajasthan)

Resourcesat L-IV

HARSAC CPB

Town Park, Hisar

Hisar Jail-II

Karan Lake, Karnal

PARLIAMENT HOUSE

CANNAUGHT PLACE

RASTRAPATI BHAWAN

N. DELHI RAILWAY STATION

WORLD VIEW-1

Env. Scs.& Engg. Deptt,T.B.4,GJU