Presentation on theme: "PRINCIPLES OF REMOTE SENSING"— Presentation transcript:
1 PRINCIPLES OF REMOTE SENSING Lecture 1Introduction
2 GROUND RULES Assessments and Examinations: Total marks: 100 (AP - 85; YSR – 15)Distribution of my 85 marks:Mid-semester examination – 25End-semester examination – 35Assignments – 10Quizzes (3 + 1 unannounced) – 10Seminar - 5Assignments and quiz would be distributed through out the semester.
3 GROUND RULES Attendance: Attendance would be taken; 85% attendance COMPULSARYNO COMPROMISE ON PUNCTUALITY …………..
5 Lecture notes / Working folder GROUND RULESLecture notes / Working folder
6 COURSE OBJECTIVES To understand: the physics, chemistry, and technology involved in remote sensingthe techniques for preprocessing aerospace remote sensing images (processing techniques will be covered in SIP course)panchromatic, multispectral and hyperspectral remote sensing in different parts of the electromagnetic spectrum and to learn how to interpret the images acquired using these sensorsIn short, the primary objective is to provide the conceptual foundations and technical skills to apply remote sensing to solve real-world problems.
7 COURSE CONTENTS ----------------- I Quiz ------------------- II Quiz Atmospheric windows and effects, correctionsMultispectral systemsCharacteristics of important remote sensing systems: LANDSAT, IRS, ASTER, SPOT; High resolution sensorsHyperspectral systemsThermal systemsMicrowave systemsInterpretations and applications - agriculture, forestry, land-use mapping, geology, water resources etc etc.History and development of remote sensingElectromagnetic radiation - nature and sources, interaction with matter and atmosphereI QuizII Quiz… and Arial Photography/Photogrammetry.III Quiz
8 A remote sensing image (Band 1 – B) Blue penetrates clear water better than other colors - see the texture of/in the water along the shore. River shows shades of grey, depending on the depth of waterIt is absorbed by chlorophyll, and so plants don't show up very brightly in this band. That is why the fields all look drab and washed out.However, it is useful for soil/vegetation discrimination, dark fields vs light coloured fields different shades of greyRoads, inhabitations, air strip brightBreakers, very bright, beach sand bright
9 A remote sensing image (Band 2 – G) penetrates clear water fairly well, and gives excellent contrast between clear and turbid (muddy) water. It helps find oil on the surface of water, and vegetation (plant life) reflects more green light than any other visible color. Manmade features are still visible (note the airport).
10 A remote sensing image (Band 3 – R) limited water penetration. It reflects well from dead foliage, but not well from live foliage with chlorophyll. It is useful for identifying vegetation types, soils, and urban (city and town) features. Town becoming much brighter
11 A remote sensing image (Band 4 – VNIR) is good for mapping shorelinesBiomass content - It is very good at detecting and analyzing vegetation. See how the fields that looked almost the same in bands 1, 2, or even 3 have changed dramatically in band 4. But the airport has darkened.
12 A remote sensing image (Band 6 – TIR) Temperature – town area, as expected hottest; golf course cooler, so are mountain and vegetation
13 A remote sensing image (TCC) For the true color rendition, band 1 is displayed in the blue color, band 2 is displayed in the green color, and band 3 is displayed in the red color. The resulting image is fairly close to realistic - as though you took the picture with your camera and were riding in the satellite. But it is also pretty dull - there is little contrast and features in the image are hard to distinguish.
14 A remote sensing image (FCC 247) In this SWIR image, band 2 is displayed in blue, band 4 is displayed in green, and band 7 (or 5) is displayed in red. This rendition looks like a jazzed up true color rendition - one with more striking colors.
15 A remote sensing image (FCC 234) In this image, band 2 is displayed in blue, band 3 is displayed in green, and band 4 is displayed in red. This rendition looks rather strange - vegetation jumps out as a bright red because green vegetation readily reflects infrared light energy! It is similar to pictures taken from aircraft when using infrared film and is very useful for studying vegetation.
16 Remote sensing : Perspective Concept: what do we understand by remote sensing?Importance:Is it just pretty pictures or serious science?Does it add to our understanding of natural systems and resources?Applications to natural resources studies
17 Remote sensing : Concept Acquisition of information about an object without making physical contactEarth: surface, atmosphere, hydrosphere, cryosphereplanetssunstars; galaxies etc
18 Remote sensing : Concept Most widely used remote sensors: human eyesMotivation for remote sensing systemsCollection (eye), transmission (optic nerve) and storage (brain)Cannot distribute the data thoughConstant resolutionVisible part of the spectra
19 Remote Sensing : Concept The sensor collects information within its IFOV (resolution cell) without being in direct physical contact with it.The sensor can be located on ground, aircraft and spacecraft platforms.
20 Remote sensing : Concept Technology, science and art of obtaining information about an object, area, or phenomenon through the analysis of data acquired by a device that is not in contact with the object, area or phenomenon under the investigation.Technology : data collectionScience and technology : data processing and analysisScience and art : data interpretation
21 Remote sensing : Concept ASPRS formal definition of photogrammetry and remote sensing:“the art, science, and technology of obtaining reliable information about physical objects and the environment, through the process of recording, measuring and interpreting imagery and digital representations of energy patterns derived from non-contact sensor systems.”
22 A Systems View of Remote Sensing PassiveActiveVisible/IRActive MicrowaveReflected lightThermal emissionPassive MicrowaveLight amplifcation by stimulated emission of radiationLight detection and rangingLaser Profiling and LidarAltimetry, ScatterometrySynthetic Aperture RadarAerial photographyVisible/near IR/SWIR imagingPassive microwave radiometryMicrowave soundingThermal imaging
23 Remote Sensing Process Science goalData processing and analysisData AcquisitionInformation extraction1) In situ measurements (GPS, bio-mass, soil moisture, spectroradiometer, etc.)2) Remote Sensing Data(passive and active remote sensing )Visual interpretationDigital Image ProcessingScientific Visualization
24 Types and classes of remote sensing data SpatialInformationImagersAltimetersSoundersImaging spectrometersImaging radiometers(Polarimeters)ScatterometersRadiometersSpectralInformationSpectrometersIntensityInformation
26 Advantages of Remote Sensing Data can be gathered from large areas of the Earth’s surface or atmosphere in short space of time.In situ measurements are time consuming and costly over large areas. Remote Sensing is considered as cost effective.No sampling bias - consistent coverage of the entire areaResponse of objects collected in different wavelengths
27 Limitations of Remote Sensing Often oversoldProvides information only about the spectral properties of objects on the earth’s surface (and their variation in time and space). We hope that the spectral properties are proxies for the property we are interested in.Noise – atmospheric effects, topographic effects, soil/vegetation coverOften considered an end in it self (the pretty picture syndrome!) - remote sensing should enhance scientific understanding of the system under study.
28 Applications of Remote Sensing AtmosphereLithosphereHydrosphereCryospherePlanetary scienceLand cover and land useMilitary.
29 Further Reading Books : Remote Sensing and Image Interpretation, Lillesand, Kiefer, Chipman, 2007Introduction to Remote Sensing, Campbell, 1996Remote Sensing : Principles and interpretation, Sabins, 1997Physical Principles of Remote Sensing, Rees, 2001Introduction to physics and techniques of remote sensing, Elachi, 1987Remote Sensing of the Environment : An earth resource perspective, Jensen , 2000Journals :Remote Sensing of EnvironmentInternational Journal of Remote SensingIEEE Trans. Geoscience and Remote SensingPhotogrammetric Engineering and Remote SensingISPRSISPRS Photogrammetry and Remote Sensing