Introduction Of Remote Sensing | Assignment

1. Define Following Terms. 

(a) Remote Sensing : Remote Sensing is an art and science of obtaining information about an object or feature without physical coming on contact with that object or feature.

(b) Transducers : Transducers are an converts energy from one form to another form. 

➙ For example microphones and loudspeaker. 

➙ There are two types of Transducers, 

• Input Transducers [ sensor ] 
• output Transducers [ actuator ]

(C) Insitu data :  Insitu typically refer to a method of data collected or manipulation of a sample without exposure to external environment.

(d) Remotely Science Data : It referred to data that has collected by a sensor that is not indirect contact with the area being maped 

(c) Frequency :  The number of cycle of wave passing a fixed point per unit time is term as frequency

➙ f = 1/T

➙ It is measured in hertz ( Hz )

(d) Wavelength :  It is the distance between two corresponding points on the wave and its major in metres.

(e) Amplitude : It is equivalent to the height of each peak.

(f) Dispersion : It is the state of getting dispersed or spread.

(g) Statistical Dispersion : Means the extent to which a numerical data is like to very an average value

➙ In other words dispersion help to understand the distributor of data

(h) Index Of Reflection : Index of reflection is defined as the ratio of the speed of light in vacuum to its speed in a specific medium

➙ It is also referred as reflective index,

➙ n = C/V

Where,

• n = reflective index
• C = the velocity of light in vacuum ( 3*10^8 m/s )
• V = velocity of light in substance.

(i) Atmospheric window : a Range of wavelength occurs which there is relative little absorption of radiation by atmospheric gases is Term as atmospheric window. 

➙ The major Windows are divisible window from. ~ 0.3 to 0.9 micrometer.

➙ The infrared window from ~ 8 to ~13 micrometer.

➙ The microwave window at wavelength longer than ~1mm

(J) Atmospheric swimming : Atmospheric swimming is the effect observed through moving air masses which have differing refractive index.

➙ Which results in effect such as star twinkling and ultimately limits the resolution of any Remote sensing system. 

(K) Absorption : When the molecules of substance are uniformly distributed through the body of solid or liquid.

➙ This phenomena is caused absorption.

(L) Transmitance: The Transmitance is the ratio of the light pass through 2D light incident of the specimen.

(m) Reflectance : Reflectors is defined as the proportion  of perpendicular incidence light reflected from a component compared to that reflected from a standard of know reflected.

(n) Lambertian surface : A surface whose emission or scattering Lambert cosine law in which the Radiant intensity living a surface is proportional to casing of the angle from surface from normal

(o) Spectre signature : it is the reflectance as a function of wavelength also each material has a unique signature there it is used for material classification.

➙ It is the variation of reflectors on emittance of a material with respect to wavelength

➙ The spectral signature of a stars indicate the composition of the stellar atmosphere

(p) Black scattering : The Black scattering is this scattering of radiation or particle in a direct opposite to that of incident radiation due to reflection from particles of the medium traversed. 

(Q) Image : image is a representation of an object produced by means of radiation usually with a lens or micron system. 

 (R) Photography : a photography is an image created by light falling on the photosensitive surface usually photographic film or an electronic image sensor such as CCD and CHO chip. 

(S) Solar azimuth angle : It is defined as the angle between the projection of sons centre on to the horizontal plane and due to south direction.

(T) Solar Zenith Angle : Solar Zenith Angle is the angle between the sun Ray and the vertical direction

It is closely related to the Solar altitude angle which is the angle between the sun Re and a horizontal plane

(U) SWATH : As a satellite revolves around the earth the sensor since a certain portion of the Earth surface. 

➙ The area image and the surface is referred as SWATH. 

(V) Instantaneous Field Of View: In Remote Sensing it is the angle through which a detector is receiving EMR. 

➙ It is often Express as function of the ground area visible at anyone time which is depend on height and the angle of radiation respection.

(W) Nadir point : it is the direction pointing directly below a particular location that is it is one of two vertical direction at the location orthogonal to to a horizontal flat surface there.

(X) Black body : a black body is an object that observe all radiation energy reaching its surface from all the direction with all the wavelength 

(Y) White body :  if all the incident radiation falling on the body are deflected it is called as White body

(Z) Grey body : a grey body is defined as the body whose absorptivity of a surface does not very with variation in temperature and wavelength of the incident radiation. 

• Radiant Flux : It is defined as the radiant energy per unit time which is emitted, transmitted, deflected or receive by an object.

• Albedo : It is the amount of sunlight reflected by a surface and is usually Express as a percentage.

2. State The Following Law's In Details. 

1. Planck's Low : Planck's law describe the spectral density of electromagnetic radiation emitted by a black body in thermal equilibrium at a given temperature (T). Where this is no not follow of matter or energy between the body and its environment.

➙ Planck's low is a Formula for Respective radiation of an object at a given temperature as a function of frequency or wavelength

2. Newton's law

• Newton's First Law Of Motion : 

➙ The First Law Of Motion implants that thing cannot start, stop aur change direction all the themselves. 

➙ It's required some force from outside to cause such a change.

➙ This property of massive body to resist changing in their state of motion is called inertia. 

➙ Newton's first law state that a body at rest or uniform motion will continue to be at rest uniform until and unless a net external force act on it.

• Newton's Second Law Of Motion : 

➙ Newton's second law state that, the accurate of an object has produced by a net force is directly proportional to magnitude of the net force the same direction as the net force and inversely proportional to the mass of the object.

➙ Newton second law describe precise how much an object will accelerate for a given net force. 

➙ F = ma

• Newton's Third Law Of Motion

➙ Newton's third slow state that for every action there is equal opposite reaction.

3. Kepler law

➙ Kepler law of planetary motion are 3 scientific law describing the motion of planets around the sun.

#1. Kepler 1st Law - The Law Of Orbits

➙ According to Kepler 1st law, " all the planets revolves around the sun in elliptical orbits having the sun at one of the focci"

➙ The point at which planet is closed to the sun is known as perihelion and the point at which planet is further from the sun know as aphelion

➙ It is g characteristic of an ellipse that the son of the distance of any planet from which focci is constant

➙ The elliptical orbit of a planet is responsible for the occurring of sensor. 

#2. Kepler 2nd law - the law of equal areas :

➙ It's state that the radius vector down from Sun to the planets sweeps out interval of time

➙ If (R) is distance of planet from sun at perihelion and at aphelion then 

#3. Kepler 3rd Law - The Law Of Periods : 

➙ According to low of period, " the square of the time period of revolution of planet around the sun in an elliptical Orbit directly proportional to the cube of its semi measure axis.

3. Discuss the Remote Sensing process in detail. 

➙ Different objects reflect or EMIT different amount of energy in different bands of the electromagnetic spectrum.

➙ The amount of energy reflected or emitted depend on the properties of both material and the incident energy ( angle of incident, intensity and wavelength )

➙ Detection and discrimination of object or surface future is done through the uniqueness of reflected or emitted EMR from object. 

➙ A device to detect this reflected or emitted electromagnetic radiation from an object is called a 'sensor'.

➙ A vehicle used to carry the sensor is called platform ( e.g. aircraft and satellite ).

➙ Main stage of Remote sensing are following.

➙ Emission of electromagnetic radiation.

➙ Transmission of energy from source to the object.

➙ Introduction of EMR with the object and substance reflection and emission. 

➙ Transmission of energy from object to sensor.

➙ Recording of energy by the sensor.

➙ Transmission of the recorded information to the ground station Processing of the data into digital or hard copy of image Analysis of Data.

4. Define Concept Of Energy.

➙ Energy is the fundamental form of living for all living Beings.

➙ There are different form of energy on this planet. 

➙ The sun is considered as the element form of energy on the earth. 

➙ In physics energy is considered a quantitative property which can be transform from an object in order for it to perform work.

➙ According to the law of conservation of energy its state that the energy can neither we created nor destroy but can only be converted from one form to another.

➙ The moment of energy from one location to another location is known as energy transfer.

➙ Following are the 4 ways through which energy can be transferred.

• Mechanically - by the action of the force
• Electrically - by the electricity
• By the radiation - by light wave or sound wave
• By heating - by conduction

5. Discuss EMI with Particle model of wave model.

(A) Particle model : Niels Bohr and next plan proposed the Quantum theory of electromagnetic radiation.

➙ This year state the energy transformed in discrete Packet call photons or quanta. 

➙ The relationship between the frequency of radiation Express by wave theory and the energy of quantum is. 

➙ This is energy of quantum is inversely proportional to its wavelength. 

➙ I.e.  the longer the wavelength involved lower its energy constant 

➙ Naturally emitted long wavelength radiation is more difficult to since remotely than sorted wavelength emission.

➙ Another implication is that long wavelength sensor must view longer area of the earth at any given time in order to obtain a detectable signal. 

(B) Wave Model : In 1860 James clerks Maxwell conceptualized electromagnetic radiation as an electromagnetic wave that travel through space at the speed of light which is 3 * 10 ^ 8 m/s. 

➙ A useful relation for quick calculation that light travel about one feet/ nenosec. 

➙ The electromagnetic wave consists of two fluctuations fields 

1. Electric 
2. Magnetic 

➙ The two vector are at right angle to one another and both are perpendicular to the Direction of Travel. 

6. Discuss the interaction of EMR with atmosphere. 

➙ The sun is the source of radiation and EMI from the sun that is reflected by Earth and detect by the satellite or aircraft sensor must pass through the atmosphere twice. 

➙ Once on it's journey from the sun to earth and other time after being reflected by the surface of the earth back to sensor.

➙ Introduction of the direct solar radiation and reflected radiation from the target with the atmosphere constituent interference with the process of Remote sensing. 

➙ This is called as "atmospheric effect". 

➙ The introduction of EMR with atmosphere is important to Remote Sensing for 2 main reasons. 

1st reason :  is it is carried by EMR deflected emitted by the earth surface is modified while travelling through the Atmospheric.

2nd reason : The interaction of EMR with the atmosphere can be used to obtain useful information about the atmosphere itself.

➙ The atmospheric constituent scale and absorb the radiation modulating radiation reflected from the target by attenuating it changing its special distribution and introducing radiation from sunlight scatter in the atmosphere and the energy reflected from nearby ground area. 

➙ Both scattering and absorption very in their effect from one part of spectrum to another. 

➙ The Solar Energy is subject to modification by several physical process as its pass the atoms. 

1. Scattering 
2. Absorption 
3. Reflection

7. Explain spectral deflection cow for water vegetation & wet soil, clean water and turbid water.

➙ The amount of Reflectance from a surface can be measured as function of wavelength this is referred as a spectral reflection

➙ Spectral Reflection for water clean water and Turbid water :

➙ In it's liquid state water has relative low reflectance with clean water having the greatest reflectance in the blue portion of the visible part of the spectrum.

➙ Water has highly absorb and virtually no reflectance in near IR wavelength range and beyond. 

➙ Turbit water has a higher reflect turns invisible region than clean water. 

➙ This is also true for water containing chlorophyll concentration. 

• Vegetation Spectral Reflectors Curve : 

➙ In General Health vegetation is very good absorb of EM energy in visible region. 

➙ chlorophyll strongly absorb light at wavelength around 0:45 (blue)  and 0.67 (red) micrometer and reflectance shortly in green light there force eyes perceive help vegetation as green.  

➙ Healthy friends have a high reflectors in near IR between 0.7 and 1.3 micrometre. 

 ➙ This is Premier League due to health internal structure of plants live. 

➙ As this internal structure various among different plants species near IR wavelength can be used to discriminate between different plant species. 

•Dry soil and wet soil spectral curve. 

➙ In weight soil it is a observe that spectral reflectors decrease due to more share contain soil in all spectral bands because of darker appearance of soil at moist condition. 

➙ In dry soil relative high reflectance as compared to wet soil. 

8. Discuss the advantage and disadvantage of Remote sensing. 

• Advantage of Remote sensing

• Provide data of large area
• Provide data of very remote and incredible region. 
• Able to obtain imaginary of any area over a continuous period of time through which the any natural change in landscape can be analysed. 
• Relatively in expensive when compared to employing a team of surveyor. 
• Easy  and Rapid collection of data. 
• Rapid production of map for interruption.

Disadvantage of Remote sensing : 

• Objects can be miss classified or confused.
• The interception of image required a certain skill level.
• Needs cross verification with ground survey data. 
• Data from multiple source may create confusion. 
• Distribution may occur in an image due to relative motion of sensor and source.

9. Enlist Types of Remote sensor.

➙ Based on platform :

• On ground 
• on an aircraft 
• on balloon 
• on spacecraft 
• On Satellite

➙ Based energy source : 

• Active remote sensors 
• passive remote sensors

➙ Based on number of band's :

• Multi spectral remote sensor
• Hypers spectral remote sensor
• Penochromatic remote sensor

➙ Based on image media :

• Photographic image 
• digital electronic image

➙Based On Region Of EMS Of Remote Sensor : 

• Optical remote sensor 
• photographical remote sensor 
• Thermal remote sensor 
• microwave remote sensor
• visible remote sensor

10. Discuss the classification based on platform of remote sensor based on energy source on image media on EMR and on the number of Bands.

➙ Classification based on platform of Remote sensing.

• Ground waste platform short range system 50 to 100 m
• Medium range system 150 to 250 m
• Large range system (up to 1 km)

➙ AIRBONE Based :

 ➙ Balloon Based: 

•  Altitude range is 22- 40 km.  
• Tone to probing the atmosphere. 
• Useful to test the instrument under development. 

➙ Radio Sonde : Major pressure temperature and relative humidity in atmosphere

➙ Raw in sonde : Measure wind velocity temperature pressure relative humidity 

➙ Air Craft Platform :

• High Special resolution ( 20 cm to Less )
• Analog photographic is possible
• Easily change their schedule to avoid weather problems
• Sensor maintenance and repair is easy

➙ Space Borne Platform : 

• Sensor are mounted on board a spacecraft
• Rocket satellite and space shuttle
• Cover large area
• Reply to coverage of an area of interest. 

➙ Classification on energy source : 

(1)  Active Remote Sensing : 

• It use and artificial source for energy
• For example the satellite itself can send a energy which can interact with target
• Inactive Remote Sensing humans can control the nature of source of energy
• Active Remote Sensing can be carried out during day and night weather condition
• E.g. RADAR 

(2) Passive Remote Sensing.

• It's depend on nature source to provide energy.
• The sun is the most useful and commonly used source of energy for passive Remote Sensing.
• The satellite sensor in this case record Primary the radiation that is reflected from target.

➙ Classification based on electromagnetic spectrum

1. Optical Remote Sensing

➙ The optical Remote Sensing is device operates in the visible near infrared middle infrared infrared and short wave infrared portion of electromagnetic spectrum

➙ This device are sensitive to the wavelength ranging from 300 NM to 3000 NM

2. Microwave Remote Sensing 

➙ It's record the Black scattered microwave Hindi wavelength range of 1 nanometer to 1 m of electromagnetic spectrum

➙ Most of microwave sensors are active sensors having their own source of energy

3. Thermal Remote Sensor 

➙ Thermal Remote which operate in thermal range of electromagnetic spectrum record the energy emitted from earth range of 3000 nanometer to 5000 NM and 8000 NM to 14000 nanometer.  

11. Discuss the orbital system for Remote Sensing.

➙ When a satellite is launch into the space it's move in a well defined path around the earth which is called as orbit of satellite.

➙ Special and temporal coverage of satellite depend on the orbit. 

➙ There are three basic types of orbit in use. 

• Geo Synchronous Orbit
• Polar or near polar Orbit
• Sun - synchronous orbit

• GEO Synchronous Orbit

➙ It is the one in which time required for the satellite to cover one Revolution is the same as the for the earth to remote on its polar axis. 

➙ In order to achieve this Orbit period Geo Synchronous Orbit are generally at very high altitude near 36000 km.

➙ They are located in equaorial plane. 

➙ This from a point on equator the satellite appear to be stationary. 

➙ The satellite revolves in the same direction as that on the earth. 

➙ Ex. INSAT, GOES, GMS etc. Which are used for communication and Meteorological satellites. 

• Polar Orbit : 

➙ This Orbit have near 90° inclination.

➙ Polar Orbit are usually medium or low Orbit compared to the GEO Synchronous Orbit. 

➙ Consequently the orbit period is less which typically various form 90-130 mints. 

➙ Therefore satellite in the polar Orbit make more than one Revolution around the earth in a single day. 

➙ The national oceanic and atmospheric series of satellite like, NOAA17, NOAA18 are all example of Polar Orbit satellite. 

• Sun synchronous orbit : 

➙ This is a special case of Polar Orbit

➙ Like a polar Orbit the satellite travel from the north to south pole as the earth turn below it. 

➙ In Sun synchronous orbit the satellite pass over the sum part of the earth at roudly the same local time each day.  

➙ This Orbit are between 700 to 800 km altitude. 

➙ This are used for satellite that need to constant amount of sunlight. 

➙ A Typically Sun synchronous satellite complete 14 orbits a day and each success you orbit is Swift over the Earth surface by around 2875 km at the equator. 

12. Explain the concept of SWATCH and NADIR ? 

• SWATCH : 

➙ As a satellite revolves around the earth the sensors see a certain portion of the Earth surface. 

➙ The area image on the surface is referred to as SWATCH

➙ The age of the appear Disk of a celestial body also used to refer to other edge of the sensors SWATCH

• NADIR : 

➙ The point on the earth surface directly below the satellite special resolution is optimal you are also called as sub satellite point. 

➙ The NADIR is directly point name directly below particular location that is one of two vertical direction at a specified location to a horizontal flat surface there. 

➙ NADIR also referred to the downward facing weaving geometric of orbit satellite. 

13. Enlist and explain the sensor resolution in detail. 

➙ Special Resolution : 

➙ In Terms of digital image special resolution referred to the number of pixel utilised in construction of the image. 

➙ Image having highest pecial resolution are compared with great term number of pixel then those of lower special resolution. 

➙ Special resolution is important as it influence how sharply we see object

Spectral Resolution : 

➙ It describe the ability of a sensor to define find wavelength interval.

➙ Senior with highest spectral resolution required for detain distribution.

➙ The fine the spectral resolution the narrow the wavelength range for a particular channel or band.

Radio Matric Resolution : 

➙ Imaginary data are represented by positive digital number which very from 0 to a selected power of 2 

➙ This maximum number of brightness level available depend on the number of birds used in representative the energy recorded.