Study of NDVI, Land Surface Temperature using Landsat (TM) Data

# Study of NDVI, Land Surface Temperature using Landsat (TM) Data

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## Study of NDVI, Land Surface Temperature using Landsat (TM) Data

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1. Study of NDVI, Land Surface Temperature using Landsat (TM) Data Mirza Muhammad Waqar Contact: mirza.waqar@ist.edu.pk +92-21-34650765-79 EXT:2257 RG610 Course: Introduction to RS & DIP

2. Landsat TM(07-03-2010)

3. Calculating Slope for Band= 3, 4 and 6 LMAX_BAND1 = 193.000 LMIN_BAND1 = -1.520 LMAX_BAND2 = 365.000 LMIN_BAND2 = -2.840 LMAX_BAND3 = 264.000 LMIN_BAND3 = -1.170 LMAX_BAND4 = 221.000 LMIN_BAND4 = -1.510 LMAX_BAND5 = 30.200 LMIN_BAND5 = -0.370 LMAX_BAND6 = 15.303 LMIN_BAND6 = 1.238 LMAX_BAND7 = 16.500 LMIN_BAND7 = -0.150 Slope= (LMAX-LMIN)/(Max Gray) Slope(B3)= (264+1.170)/(255)= 1.0398 Slope(B4)= (221+1.51)/(255)= 0.8725 Slope(B6)= (15.303-1.238)/(255)= 0.0551

4. Calculating Radiance for Band= 3, 4 and 6 LMAX_BAND1 = 193.000 LMIN_BAND1 = -1.520 LMAX_BAND2 = 365.000 LMIN_BAND2 = -2.840 LMAX_BAND3 = 264.000 LMIN_BAND3 = -1.170 LMAX_BAND4 = 221.000 LMIN_BAND4 = -1.510 LMAX_BAND5 = 30.200 LMIN_BAND5 = -0.370 LMAX_BAND6 = 15.303 LMIN_BAND6 = 1.238 LMAX_BAND7 = 16.500 LMIN_BAND7 = -0.150 Radiance= Slope*DN + LMIN R(3)= 1.0398 *B3-1.170 R(4)= 0.8725*B4-1.510 R(6)= 0.0551*B6-1.238

5. Calculating Radiance for Band= 3, 4 and 6 Radiance for Band 6

6. Calculating Brightness Temperature using Planck's Black Body Radiation Law TB = K2/Log{(K1/R6)+1)} Where: K1 = Calibration constant 1 (666.09 watt/m2 * ster * µm)K2 = Calibration constant 2 (1282.71 K)

7. Calculating Surface Temperature Surface Temperature= TB /{1+(λ *BT/ρ*logε)} TB= Brightness Temperatureλ = Wavelength of emitted radiance (11.5 µm)ρ = h x c/σ =1.438 x 10-2 mK (σ=Boltzmann constant=1.38 x 10-23 J/K, h=Planck’s constant=6.626 x 10-34 Js, c=velocity of light=2.998 x 108 m/s) ε = Land surface emissivity

8. Calculating Land surface emissivity (LSE)- ε • LSE (ε) can be extracted by using NDVI considering three different cases • Bare ground • Fully vegetated and • Mixture of bare soil and vegetation • For Band 6 of Landsat TM • ε = 0.004*Pv + 0.986 • Pv is the proportion of vegetation which is given by • Pv = [(NDVI-NDVImin)/(NDVImax-NDVImin)]2

9. Calculating Pv NDVI = [Ref(B4)-Ref (B3)}/{Ref (B4)+Ref(B3)} Pv

10. Pv = [(NDVI-NDVImin)/(NDVImax-NDVImin)]2

11. Calculating ε LSE ε = 0.004*Pv + 0.986

12. Calculating ε Logε

13. Calculating Surface Temperature Surface Temperature= TB /{1+(λ *BT/ρ) *logε} λ = Wavelength of emitted radiance (11.5 µm)ρ = h x c/σ =1.438 x 10-2 mK (σ=Boltzmann constant=1.38 x 10-23 J/K, h=Planck’s constant=6.626 x 10-34 Js, c=velocity of light=2.998 x 108 m/s)

14. Land Surface Temperature (LST)