SLIDE 1
SLIDE 2 The The MODerate MODerate resolution Imaging resolution Imaging Spectroradiometer Spectroradiometer (MODIS) on (MODIS) on-
- board the Earth Observing System/NASA Terra and Aqua satellites
board the Earth Observing System/NASA Terra and Aqua satellites offers new
capabilities for the study of land surfaces with a spatial resol capabilities for the study of land surfaces with a spatial resolution up to 250 m. ution up to 250 m. Prior to the derivation of various land parameters from Prior to the derivation of various land parameters from radiometrically radiometrically calibrated MODIS data, the signals measured by the instrument at calibrated MODIS data, the signals measured by the instrument at the top of the the top of the atmosphere need to be converted to surface reflectance, that is, atmosphere need to be converted to surface reflectance, that is, to the to the reflectance that would be measured by MODIS at the ground level reflectance that would be measured by MODIS at the ground level without the without the atmosphere. atmosphere. The process necessary for that conversion is called atmospheric The process necessary for that conversion is called atmospheric
- correction. It uses the calibrated data as input and performs co
- correction. It uses the calibrated data as input and performs corrections for the
rrections for the effect of gaseous absorption, molecules and aerosol scattering, effect of gaseous absorption, molecules and aerosol scattering, coupling coupling between atmospheric and surface bidirectional reflectance functi between atmospheric and surface bidirectional reflectance function.
Goals: Goals:
Present Present the the approaches and codes used approaches and codes used at at Altai State University for the Altai State University for the atmospheric correction of visible to middle atmospheric correction of visible to middle-
- infrared MODIS data and for
infrared MODIS data and for retrieval of land parameters such as the vegetation indices, bid retrieval of land parameters such as the vegetation indices, bidirectional irectional reflectance distribution function, reflectance distribution function, albedo albedo, snow mask. , snow mask.
SLIDE 3
SLIDE 4 The components affecting the remote sensing signal in The components affecting the remote sensing signal in the the 0.4 0.4-
2.5 µ µm m range range
SLIDE 5
SLIDE 6
Altai region, October Altai region, October 13 13, , 2003 2003
SLIDE 7
After atm ospheric After atm ospheric corrections ( PGE1 1 ) corrections ( PGE1 1 ) Scene of the Scene of the October October 1 3 1 3 , , 2 0 0 3 2 0 0 3
0 .5 0 .0 1 .0
Atmospheric correction Atmospheric correction and and АОТ АОТ_ _0,66 0,66 for fires for fires
SLIDE 9
Altai region. May Altai region. May 12 12, , 2006 2006
SLIDE 10 1 - without atmospheric corrections 2 - with atmospheric corrections. 3 - difference NDVI (2) – NDVI(1)
NDVI distribution function for the South NDVI distribution function for the South-
W estern Siberia according to MODI S/ Terra data, October according to MODI S/ Terra data, October 1 3 , 2 0 0 3 1 3 , 2 0 0 3
SLIDE 11 NDVI distribution function for the South NDVI distribution function for the South-
W estern Siberia, May May 1 2 , 2 0 0 6 1 2 , 2 0 0 6
SLIDE 12 NDVI distribution function for the South NDVI distribution function for the South-
W estern Siberia, May May 1 5 , 2 0 0 6 1 5 , 2 0 0 6
SLIDE 13
Key causes for land surface reflectance anisotropy Key causes for land surface reflectance anisotropy
SLIDE 14
MODIS BRDF/ MODIS BRDF/Albedo Albedo Processing Scheme Processing Scheme
SLIDE 15 Nadir Sun Nadir Sun-
- View reflectance ( bands 1
View reflectance ( bands 1 -
4 -
3 ) ( From 1 1 th to 2 5 th ( From 1 1 th to 2 5 th Juny Juny, 2 0 0 6 ) , 2 0 0 6 )
SLIDE 16 Atm ospherically corrected Atm ospherically corrected reflectances reflectances, bands 1 , bands 1 -
4 -
3 ( June 2 2 , 2 0 0 6 ) ( June 2 2 , 2 0 0 6 )
SLIDE 17 Black Black -
sky albedo albedo for 4 5 degrees solar zenith, band 1 for 4 5 degrees solar zenith, band 1 ( From 1 1 th to 2 5 th ( From 1 1 th to 2 5 th Juny Juny, 2 0 0 6 ) , 2 0 0 6 )
SLIDE 18 W hite W hite-
sky albedo albedo, band 1 , band 1 ( From 1 1 th to 2 5 th ( From 1 1 th to 2 5 th Juny Juny, 2 0 0 6 ) , 2 0 0 6 )
SLIDE 19 Snow m apping Snow m apping Criteria Criteria applied in snow mapping using applied in snow mapping using MODIS data MODIS data
R4 R4 ≥ ≥ 0,1 0,1 4 4 0,05 0,05 ≤ ≤ NDSI <0,4 and NDSI <0,4 and NDVI = (R2 NDVI = (R2 – – R1) / (R2+R1) R1) / (R2+R1) Є Є D D 3 3 R2 > 0,11 R2 > 0,11 2 2 NDSI = (R4 NDSI = (R4 – – R6) / (R4 + R6) R6) / (R4 + R6) ≥ ≥ 0,4 0,4 1 1 Criterion Criterion Number Number
- Hall D. K. et al. // Remote
Hall D. K. et al. // Remote Sens
- Sens. Environ., 1995, v. 54, pp. 127
. Environ., 1995, v. 54, pp. 127-
140.
- Hall D. K. et al. // Remote
Hall D. K. et al. // Remote Sens
- Sens. Environ., 1998, v. 66, pp. 129
. Environ., 1998, v. 66, pp. 129-
137.
Klein A. G. et al. //Hydrol
- Hydrol. Process., 1998, v. 12, pp. 1723
. Process., 1998, v. 12, pp. 1723-
1744.
- Hall D. K. et al. Algorithm theoretical basis document (ATBD) f
Hall D. K. et al. Algorithm theoretical basis document (ATBD) for the MODIS snow and sea ice
- r the MODIS snow and sea ice-
- mapping
mapping
- algorithms. NASA EOS
- algorithms. NASA EOS-
- MODIS Doc., 2001, 55 p.
MODIS Doc., 2001, 55 p. Reflectance of Reflectance of snow snow, , water water, , soil and soil and vegetation vegetation ( (according to according to Klein A. G. Klein A. G. et al. et al., 1998) , 1998) and location of the and location of the MODIS channels MODIS channels (1 (1 – – 7) 7)
SLIDE 20 NDSI NDSI versus versus NDVI NDVI plot for snow plot for snow-
covered siberian siberian forests. forests.
, -
Klein A. G. et al., , 1998 1998
SLIDE 21
Snow m apping. MODI S data. March Snow m apping. MODI S data. March 2 1 2 1 , , 2 0 0 6 2 0 0 6
SLIDE 22
Snow m apping. MODI S data. April 2 0 , Snow m apping. MODI S data. April 2 0 , 2 0 0 6 2 0 0 6
SLIDE 23
Snow m apping. MODI S data. May Snow m apping. MODI S data. May 1 5 1 5 , , 2 0 0 6 2 0 0 6
