MODIS (Aqua/Terra)-Image Processing (2)
continues from previous entry...http://ajiputrap.blogspot.com/modis-image-processing.html
" temperature brightness " or " temperature brightness value "
Aqua MODIS image processing for sea surface temperature using two bands : band 31 and band 32 (that have processed for corrected radiance value).
We need to convert radiance value both bands (31 and 32) to Brightness Value using “Planck”:
Tb = c2/(Vi * ln (c1/(Vi5 * radiance) + 1))
where Tb = Brightness Value (K),
c1 = Constanta radiance (1.1910659x108 [W m -2sr-1 (µm-1 )-4 ])
c2 = Constanta radiance (1.438833 x 104 [K µm])
Vi = central wavelength
below are table for central wavelength - Aqua/Terra MODIS Bands..
For AQUA MODIS =
Band 20 : 3.7803
Band 22 : 3.9720
Band 23 : 4.0617
Band 31 : 11.0263
Band 32 : 12.0424
For TERRA MODIS =
Band 22 : 3.9719
Band 23 : 4.0567
Band 31 : 11.0073
Band 32 : 12.0020
-----------------------------------------------------------------------------------
nice to share
Aji PP
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Showing posts with label HDF. Show all posts
Showing posts with label HDF. Show all posts
Thursday, January 22, 2009
Wednesday, January 21, 2009
MODIS (Aqua/Terra)-Image Processing (1)
MODIS (Aqua/Terra)-Image Processing (1)
this is just a little bit sharing... :)
you may or have been read :
http://ajiputrap.blogspot.com/search/label/Aqua
http://ajiputrap.blogspot.com/search/label/Aqua%2FTerra%20MODIS
http://ajiputrap.blogspot.com/search/label/MODIS
After we download MODIS (Aqua/Terra) Level 1B Radiance Calibrated (1KM, 500m and 250m, opr you just download 1KM only (its already consist of 250m and 500m that aggregated to 1km) and Level 1A Geolocation (for extracting LAND SEA MASK).
The next step is to open HDF MODIS data in Image Processing Software, such as ENVI...
in this post i would like to share about open HDF MODIS DATA, View HDF DATASETS and other steps in image processing using software ENVI 4.x.
1. In ENVI 4.x u may open HDF MODIS DATA through two ways:
a. Open HDF MODIS data from:
File -> Open External Files -> General Format -> HDF
U will see HDF Dataset Selection, and then choose Datasets (that to be opened)
Click OK
Choose BSQ and click OK (repeated until 4 times, depend on number of dataset opened)
b. Or u may open directly from
File -> Open Image File
Will open all modis data from MYD021KM: Reflectance and Radiance Bands (1- 19 and 26) also Emissive Bands (20-25 and 27-36)
Your MODIS DATA will opened in ENVI 4.x
2. View HDF Datasets of MODIS
from ENVI 4.x main menu..choose Basic Tools->Preprocessing->Data Specific Utilities -> View HDF Datasets Attributes
and then choose your MODIS DATA...
u can read my previous posting :
http://ajiputrap.blogspot.com/2008/12/modis-hdf-hierarchical-data-format.html
3. Radiometric Correction
Radiometric Correction in ENVI use Band Math (ENVI main menu, choose Basic Tool -> Band Math)
Radiance bands calculated using this formula :
Rb = R_scaleb ( SIb – R_offsetsb)
where :
Rb = Radiance of band-b
R_Scaleb = Radiance scale of band-b
SIb = Sign Integer of band-b
R_offset¬sb = Radiance offsets of band-b
Radiance value of sensor zenith calculated using this formula :
Rz = R_scalez * iz * pi/180
dimana :
Rz = Radiance value of sensor zenith
R_scalez = Radiance scale of sensor zenith
iz = Sensor zenith
Reflectance Bands calculated for visible and thermal infrared (1 – 19 and 26 bands) with this formula:
Refb = Ref_Scaleb * (Bb - Ref_offsetsb)
where: Refb = Reflectance of band- b
Ref_Scaleb = Reflectance scale
Bb = Band -b
Ref_offsetsb = Reflectance offset band- b
4. applied formula or algorithm (for Sea Surface Temperature or Chlorophyll-a)
MODIS can help us to detecting Chlorophyll-a (Chlor-a) with formula or algorithm from Carder et al. :
Chlor-a=(10^(0.2818-(2.783*alog10(B10/B12))+(1.863*((alog10(B10/B12))^2))-
(2.387*((alog10(B10/B12))^3))))
where : B10 = Reflecance of Band 10
B12 = Reflecance of Band 12
- above is the formula of Chlor-a in Band Math of ENVI.
Aqua MODIS image processing for sea surface temperature using two bands : band 31 and band 32 (that have processed for corrected radiance value).
We need to convert radiance value both bands (31 and 32) to Brightness Value using “Planck”:
Tb = c2/(Vi * ln (c1/(Vi5 * radiance) + 1))
where Tb = Brightness Value (K),
c1 = Constanta radiance (1.1910659x108 [W m -2sr-1 (µm-1 )-4 ])
c2 = Constanta radiance (1.438833 x 104 [K µm])
Vi = central wavelength
You can use band math ENVI 4.x and put this formula:
(1.438833*10000)/(11.0263*(alog((1.1910659*100000000)/(11.0263^5*b31))/1))
where :
b31 = band 31
to determine or get information of Sea Surface Temperature you may use this algorithm from Brown and Minnet :
SPL =
1.152+0.96*(B1-273)+0.151*(B1-B2)*(B3-273)+2.021*(B1-B2)*(1/COS(B4)-1)
where
B1 = Brightness Value of band 31
B2 = Brightness Value of band 32
B3 = Brightness Value of band 20
B4 = Radiance Value of sensor zenith
=========
Regards,
Aji Putra Perdana
this is just a little bit sharing... :)
you may or have been read :
http://ajiputrap.blogspot.com/search/label/Aqua
http://ajiputrap.blogspot.com/search/label/Aqua%2FTerra%20MODIS
http://ajiputrap.blogspot.com/search/label/MODIS
After we download MODIS (Aqua/Terra) Level 1B Radiance Calibrated (1KM, 500m and 250m, opr you just download 1KM only (its already consist of 250m and 500m that aggregated to 1km) and Level 1A Geolocation (for extracting LAND SEA MASK).
The next step is to open HDF MODIS data in Image Processing Software, such as ENVI...
in this post i would like to share about open HDF MODIS DATA, View HDF DATASETS and other steps in image processing using software ENVI 4.x.
1. In ENVI 4.x u may open HDF MODIS DATA through two ways:
a. Open HDF MODIS data from:
File -> Open External Files -> General Format -> HDF
U will see HDF Dataset Selection, and then choose Datasets (that to be opened)
Click OK
Choose BSQ and click OK (repeated until 4 times, depend on number of dataset opened)
b. Or u may open directly from
File -> Open Image File
Will open all modis data from MYD021KM: Reflectance and Radiance Bands (1- 19 and 26) also Emissive Bands (20-25 and 27-36)
Your MODIS DATA will opened in ENVI 4.x
2. View HDF Datasets of MODIS
from ENVI 4.x main menu..choose Basic Tools->Preprocessing->Data Specific Utilities -> View HDF Datasets Attributes
and then choose your MODIS DATA...
u can read my previous posting :
http://ajiputrap.blogspot.com/2008/12/modis-hdf-hierarchical-data-format.html
3. Radiometric Correction
Radiometric Correction in ENVI use Band Math (ENVI main menu, choose Basic Tool -> Band Math)
Radiance bands calculated using this formula :
Rb = R_scaleb ( SIb – R_offsetsb)
where :
Rb = Radiance of band-b
R_Scaleb = Radiance scale of band-b
SIb = Sign Integer of band-b
R_offset¬sb = Radiance offsets of band-b
Radiance value of sensor zenith calculated using this formula :
Rz = R_scalez * iz * pi/180
dimana :
Rz = Radiance value of sensor zenith
R_scalez = Radiance scale of sensor zenith
iz = Sensor zenith
Reflectance Bands calculated for visible and thermal infrared (1 – 19 and 26 bands) with this formula:
Refb = Ref_Scaleb * (Bb - Ref_offsetsb)
where: Refb = Reflectance of band- b
Ref_Scaleb = Reflectance scale
Bb = Band -b
Ref_offsetsb = Reflectance offset band- b
4. applied formula or algorithm (for Sea Surface Temperature or Chlorophyll-a)
MODIS can help us to detecting Chlorophyll-a (Chlor-a) with formula or algorithm from Carder et al. :
Chlor-a=(10^(0.2818-(2.783*alog10(B10/B12))+(1.863*((alog10(B10/B12))^2))-
(2.387*((alog10(B10/B12))^3))))
where : B10 = Reflecance of Band 10
B12 = Reflecance of Band 12
- above is the formula of Chlor-a in Band Math of ENVI.
Aqua MODIS image processing for sea surface temperature using two bands : band 31 and band 32 (that have processed for corrected radiance value).
We need to convert radiance value both bands (31 and 32) to Brightness Value using “Planck”:
Tb = c2/(Vi * ln (c1/(Vi5 * radiance) + 1))
where Tb = Brightness Value (K),
c1 = Constanta radiance (1.1910659x108 [W m -2sr-1 (µm-1 )-4 ])
c2 = Constanta radiance (1.438833 x 104 [K µm])
Vi = central wavelength
You can use band math ENVI 4.x and put this formula:
(1.438833*10000)/(11.0263*(alog((1.1910659*100000000)/(11.0263^5*b31))/1))
where :
b31 = band 31
to determine or get information of Sea Surface Temperature you may use this algorithm from Brown and Minnet :
SPL =
1.152+0.96*(B1-273)+0.151*(B1-B2)*(B3-273)+2.021*(B1-B2)*(1/COS(B4)-1)
where
B1 = Brightness Value of band 31
B2 = Brightness Value of band 32
B3 = Brightness Value of band 20
B4 = Radiance Value of sensor zenith
=========
Regards,
Aji Putra Perdana
Thursday, January 15, 2009
MODIS phytoplankton-ENVI
MODIS phytoplankton-ENVI
I would like to discuss about "MODIS phytoplankton-ENVI".
title of this my blog post today is about Aqua/Terra MODIS image processing for detecting phytoplankton using software ENVI.
Let's start this discussion from the last word :"ENVI"
What is ENVI??
1. ENVI
We know that ENVI is great image processing and analyzing geospatial imagery.
ENVI is the premier software solution for processing and analyzing geospatial imagery used by GIS professionals, scientists, researchers, and image analysts around the world. ENVI software combines the latest spectral image processing and image analysis technology with an intuitive, user-friendly interface to help you get meaningful information from imagery.
ENVI provides us MODIS Toolkit and Ocean Color Plug-ins (previous posting : http://ajiputrap.blogspot.com/2008/12/modis-toolkit-and-ocean-color-plug-ins.html)
ENVI help us in MODIS image processing with geometric correction (bow-tie correction).
- I have uploaded in my esnips simple tutorial Aqua/Terra MODIS image processing using ENVI 4.x
http://ajiputrap.blogspot.com/2009/01/pengolahan-citra-aquaterra-modis-dengan.html
download this tutorial:
pengolahan citra modis dengan envi.pdf
-- step by step from open MODIS HDF (Level 1B), MODIS Geometric Correction (include Bow-Tie Correction), Radiometric Correction for Reflectance and Radiance Bands (use Band Math).
Another tutorial files can be downloaded in http://www.esnips.com/web/perdana09-article :
- SeaDAS_4_AquaMODIS.pdf
Tutorial Aqua/Terra MODIS image processing using SeaDAS software
- Langkah Order Citra MODIS.pdf
How to order MODIS (level 1B at Ladsweb)
2. phytoplankton
phytoplankton ??
Phytoplankton are the autotrophic component of the plankton community. The name comes from the Greek words phyton, or "plant", and πλαγκτος ("planktos"), meaning "wanderer" or "drifter".[1] Most phytoplankton are too small to be individually seen with the unaided eye. However, when present in high enough numbers, they may appear as a green discoloration of the water due to the presence of chlorophyll within their cells (although the actual color may vary with the species of phytoplankton present due to varying levels of chlorophyll or the presence of accessory pigments such as phycobiliproteins, xanthophylls, etc.).
Phytoplankton obtain energy through a process called photosynthesis and must therefore live in the well-lit surface layer (termed the euphotic zone) of an ocean, sea, lake, or other body of water.
Phytoplankton are a key food item in both aquaculture and mariculture. Both utilize phytoplankton for the feeding of the animals being farmed. In mariculture, the phytoplankton is naturally occurring and is introduced into enclosures with the normal circulation of seawater. In aquaculture, phytoplankton must be obtained and introduced directly.
References
1. ^ Thurman, H. V. (1997). Introductory Oceanography. New Jersey, USA: Prentice Hall College. ISBN 0132620723.
2. ^ "Satellite Sees Ocean Plants Increase, Coasts Greening". NASA (2 March 2005). Retrieved on 12 January 2009.
3. ^ Richtel, M. (May 1, 2007), "Recruiting Plankton to Fight Global Warming", New York Times, http://www.nytimes.com/2007/05/01/business/01plankton.html?ref=science
4. ^ Hallegraeff, G.M. (2003). Harmful algal blooms: a global overview. in Hallegraeff, G.M., Andewrson, D.M. and Cembella, A.D. (eds) 2003. Manual on Harmful Marine Microalgae. UNESCO, Paris
5. ^ G.E. Hutchinson (1961). "The paradox of the plankton". Am. Nat. 95: 137–145. doi:10.1086/282171.
6. ^ a b c d McVey, James P., Nai-Hsien Chao, and Cheng-Sheng Lee. CRC Handbook of Mariculture Vol. 1 : Crustacean Aquaculture. New York: C R C P LLC, 1993.
== source information : http://en.wikipedia.org/wiki/Phytoplankton ==
interesting question about phyto...
Where Are Phytoplankton?
The distribution of phytoplankton in the ocean have been measured by special instruments in space since 1979. The instruments, called ocean-color scanners, measure the color of the ocean. Color is proportional to the amount of chlorophyll pigments close to the surface, except in sediment-rich water very close to coasts. And the amount of chlorophyll is proportional to the amount of phytoplankton in the water. Water with great numbers of phytoplankton are green. Pure ocean water is deep navy blue.
The first ocean-color scanner, the Coastal Zone Color Scanner, was launched on the Nimbus-7 satellite in 1978. It was followed many years later by SeaWiFS (Sea-viewing Wide Field-of-view Sensor) on the Seastar satellite launched in 1997. The most recent color scanner is MODIS (Moderate Resolution Imaging Spectrometer) on the Terra spacecraft launched in 1999 and the Aqua satellite launched in 2002.
more information about distribution of phyto...read this article : Distribution of Plankton
summary from the article:
Phytoplankton are abundant in regions where:
1. Winds are able to mix nutrients up into near surface waters from deeper in the ocean, or
2. Where Ekman transports driven by the winds pulls water up from deeper in the ocean,
a. When winds blow toward the equator along west coasts of continents, and
b. When the average winds blowing at different speeds and directions cause divergence of the Ekman transports,provided a small amount iron needed by the protists is in the water.
--- MODIS (Moderate Resolution Imaging Spectrometer) on the Terra spacecraft and the Aqua satellite help us daily in monitoring or detecting phytoplankton. ---
3. MODIS (Moderate Resolution Imaging Spectrometer)
please read previously article about MODIS (http://ajiputrap.blogspot.com/search/label/MODIS)
or directly from http://modis.gsfc.nasa.gov
===================================================================================
Step by step Aqua/Terra MODIS (Level 1B) image processing using ENVI 4.2 software:
1. Download MODIS data level 1B 1km resolution from ladsweb...
2. Open HDF MODIS in ENVI 4.x
File -> Open External File -> Generic Format -> HDF (http://ajiputrap.blogspot.com/2008/12/modis-hdf-hierarchical-data-format.html or http://ajiputrap.blogspot.com/search/label/HDF)
3. Geometric Correction, include Bow-Tie Correction*
Bowtie Correction aims to improve image at overlapped data. Overlap occurs because there is increasing instantaneous field of view (IFOV) of 1x1 km in the lowest point (nadir). Being close to almost 2 x 5 km at the maximum scan angle is 55 degree.
After MODIS DATA geometrically corrected, then go to the next step
4. Radiometric Correction
Radiometric Correction in ENVI use Band Math (ENVI main menu, choose Basic Tool -> Band Math)
Reflectance Bands calculated for visible and thermal infrared (1 – 19 and 26 bands) with this formula:
Refb = Ref_Scaleb * (Bb - Ref_offsetsb)
where: Refb = Reflectance of band- b
Ref_Scaleb = Reflectance scale
Bb = Band -b
Ref_offsetsb = Reflectance offset band- b
-- information about reflectance scale and offset we may get it from HDF Dataset (http://ajiputrap.blogspot.com/2008/12/modis-hdf-hierarchical-data-format.html or http://ajiputrap.blogspot.com/search/label/HDF)
5. Chlorophyll-a algorithm with Band Math
After we get geometric and radiometrically corrected MODIS image, we continue to the main step : detecting Chlorophyll-a
Fitoplankton that is on a layer of light contains Chlorophyll-a useful for photosynthesis. Chlorophyll-a able to absorb a light blue and green, so it can detect the existence fitoplankton based on the ability of these Chlorophyll-a.
MODIS can help us to detecting Chlorophyll-a (Chlor-a) with formula or algorithm from Carder et al. :
Chlor-a=(10^(0.2818-(2.783*alog10(B10/B12))+(1.863*((alog10(B10/B12))^2))-
(2.387*((alog10(B10/B12))^3))))
where : B10 = Reflecance of Band 10
B12 = Reflecance of Band 12
- above is the formula of Chlor-a in Band Math of ENVI.
In addition Chlorophyll-a , we may use sea surface temperature from MODIS to get information distribution of phytoplankton in the ocean. if we combined both we may get great information...
==================================================================================
nice to share :)
Best Regards,
Aji Putra Perdana
I would like to discuss about "MODIS phytoplankton-ENVI".
title of this my blog post today is about Aqua/Terra MODIS image processing for detecting phytoplankton using software ENVI.
Let's start this discussion from the last word :"ENVI"
What is ENVI??
1. ENVI
We know that ENVI is great image processing and analyzing geospatial imagery.
ENVI is the premier software solution for processing and analyzing geospatial imagery used by GIS professionals, scientists, researchers, and image analysts around the world. ENVI software combines the latest spectral image processing and image analysis technology with an intuitive, user-friendly interface to help you get meaningful information from imagery.
ENVI provides us MODIS Toolkit and Ocean Color Plug-ins (previous posting : http://ajiputrap.blogspot.com/2008/12/modis-toolkit-and-ocean-color-plug-ins.html)
ENVI help us in MODIS image processing with geometric correction (bow-tie correction).
- I have uploaded in my esnips simple tutorial Aqua/Terra MODIS image processing using ENVI 4.x
http://ajiputrap.blogspot.com/2009/01/pengolahan-citra-aquaterra-modis-dengan.html
download this tutorial:
pengolahan citra modis dengan envi.pdf
-- step by step from open MODIS HDF (Level 1B), MODIS Geometric Correction (include Bow-Tie Correction), Radiometric Correction for Reflectance and Radiance Bands (use Band Math).
Another tutorial files can be downloaded in http://www.esnips.com/web/perdana09-article :
- SeaDAS_4_AquaMODIS.pdf
Tutorial Aqua/Terra MODIS image processing using SeaDAS software
- Langkah Order Citra MODIS.pdf
How to order MODIS (level 1B at Ladsweb)
2. phytoplankton
phytoplankton ??
Phytoplankton are the autotrophic component of the plankton community. The name comes from the Greek words phyton, or "plant", and πλαγκτος ("planktos"), meaning "wanderer" or "drifter".[1] Most phytoplankton are too small to be individually seen with the unaided eye. However, when present in high enough numbers, they may appear as a green discoloration of the water due to the presence of chlorophyll within their cells (although the actual color may vary with the species of phytoplankton present due to varying levels of chlorophyll or the presence of accessory pigments such as phycobiliproteins, xanthophylls, etc.).
Phytoplankton obtain energy through a process called photosynthesis and must therefore live in the well-lit surface layer (termed the euphotic zone) of an ocean, sea, lake, or other body of water.
Phytoplankton are a key food item in both aquaculture and mariculture. Both utilize phytoplankton for the feeding of the animals being farmed. In mariculture, the phytoplankton is naturally occurring and is introduced into enclosures with the normal circulation of seawater. In aquaculture, phytoplankton must be obtained and introduced directly.
References
1. ^ Thurman, H. V. (1997). Introductory Oceanography. New Jersey, USA: Prentice Hall College. ISBN 0132620723.
2. ^ "Satellite Sees Ocean Plants Increase, Coasts Greening". NASA (2 March 2005). Retrieved on 12 January 2009.
3. ^ Richtel, M. (May 1, 2007), "Recruiting Plankton to Fight Global Warming", New York Times, http://www.nytimes.com/2007/05/01/business/01plankton.html?ref=science
4. ^ Hallegraeff, G.M. (2003). Harmful algal blooms: a global overview. in Hallegraeff, G.M., Andewrson, D.M. and Cembella, A.D. (eds) 2003. Manual on Harmful Marine Microalgae. UNESCO, Paris
5. ^ G.E. Hutchinson (1961). "The paradox of the plankton". Am. Nat. 95: 137–145. doi:10.1086/282171.
6. ^ a b c d McVey, James P., Nai-Hsien Chao, and Cheng-Sheng Lee. CRC Handbook of Mariculture Vol. 1 : Crustacean Aquaculture. New York: C R C P LLC, 1993.
== source information : http://en.wikipedia.org/wiki/Phytoplankton ==
interesting question about phyto...
Where Are Phytoplankton?
The distribution of phytoplankton in the ocean have been measured by special instruments in space since 1979. The instruments, called ocean-color scanners, measure the color of the ocean. Color is proportional to the amount of chlorophyll pigments close to the surface, except in sediment-rich water very close to coasts. And the amount of chlorophyll is proportional to the amount of phytoplankton in the water. Water with great numbers of phytoplankton are green. Pure ocean water is deep navy blue.
The first ocean-color scanner, the Coastal Zone Color Scanner, was launched on the Nimbus-7 satellite in 1978. It was followed many years later by SeaWiFS (Sea-viewing Wide Field-of-view Sensor) on the Seastar satellite launched in 1997. The most recent color scanner is MODIS (Moderate Resolution Imaging Spectrometer) on the Terra spacecraft launched in 1999 and the Aqua satellite launched in 2002.
more information about distribution of phyto...read this article : Distribution of Plankton
summary from the article:
Phytoplankton are abundant in regions where:
1. Winds are able to mix nutrients up into near surface waters from deeper in the ocean, or
2. Where Ekman transports driven by the winds pulls water up from deeper in the ocean,
a. When winds blow toward the equator along west coasts of continents, and
b. When the average winds blowing at different speeds and directions cause divergence of the Ekman transports,provided a small amount iron needed by the protists is in the water.
--- MODIS (Moderate Resolution Imaging Spectrometer) on the Terra spacecraft and the Aqua satellite help us daily in monitoring or detecting phytoplankton. ---
3. MODIS (Moderate Resolution Imaging Spectrometer)
please read previously article about MODIS (http://ajiputrap.blogspot.com/search/label/MODIS)
or directly from http://modis.gsfc.nasa.gov
===================================================================================
Step by step Aqua/Terra MODIS (Level 1B) image processing using ENVI 4.2 software:
1. Download MODIS data level 1B 1km resolution from ladsweb...
2. Open HDF MODIS in ENVI 4.x
File -> Open External File -> Generic Format -> HDF (http://ajiputrap.blogspot.com/2008/12/modis-hdf-hierarchical-data-format.html or http://ajiputrap.blogspot.com/search/label/HDF)
3. Geometric Correction, include Bow-Tie Correction*
Bowtie Correction aims to improve image at overlapped data. Overlap occurs because there is increasing instantaneous field of view (IFOV) of 1x1 km in the lowest point (nadir). Being close to almost 2 x 5 km at the maximum scan angle is 55 degree.
After MODIS DATA geometrically corrected, then go to the next step
4. Radiometric Correction
Radiometric Correction in ENVI use Band Math (ENVI main menu, choose Basic Tool -> Band Math)
Reflectance Bands calculated for visible and thermal infrared (1 – 19 and 26 bands) with this formula:
Refb = Ref_Scaleb * (Bb - Ref_offsetsb)
where: Refb = Reflectance of band- b
Ref_Scaleb = Reflectance scale
Bb = Band -b
Ref_offsetsb = Reflectance offset band- b
-- information about reflectance scale and offset we may get it from HDF Dataset (http://ajiputrap.blogspot.com/2008/12/modis-hdf-hierarchical-data-format.html or http://ajiputrap.blogspot.com/search/label/HDF)
5. Chlorophyll-a algorithm with Band Math
After we get geometric and radiometrically corrected MODIS image, we continue to the main step : detecting Chlorophyll-a
Fitoplankton that is on a layer of light contains Chlorophyll-a useful for photosynthesis. Chlorophyll-a able to absorb a light blue and green, so it can detect the existence fitoplankton based on the ability of these Chlorophyll-a.
MODIS can help us to detecting Chlorophyll-a (Chlor-a) with formula or algorithm from Carder et al. :
Chlor-a=(10^(0.2818-(2.783*alog10(B10/B12))+(1.863*((alog10(B10/B12))^2))-
(2.387*((alog10(B10/B12))^3))))
where : B10 = Reflecance of Band 10
B12 = Reflecance of Band 12
- above is the formula of Chlor-a in Band Math of ENVI.
In addition Chlorophyll-a , we may use sea surface temperature from MODIS to get information distribution of phytoplankton in the ocean. if we combined both we may get great information...
==================================================================================
nice to share :)
Best Regards,
Aji Putra Perdana
Monday, December 29, 2008
MODIS Toolkit and Ocean Color Plug-ins from ENVI
MODIS Toolkit and Ocean Color Plug-ins from ENVI*
What is ENVI?
ENVI is the premier software solution for processing and analyzing geospatial imagery used by GIS professionals, scientists, researchers, and image analysts around the world. ENVI software combines the latest spectral image processing and image analysis technology with an intuitive, user-friendly interface to help you get meaningful information from imagery.
-------------------------------------------------------------------------------------
Toolkits & Plugins
Quickly and easily access toolkits and plug-ins that will empower your IDL and ENVI applications. Each listing here includes code samples and documentation to help you jump start your programming or application development.
The MODIS Conversion Toolkit
The MODIS Conversion Toolkit (MCTK) is plugin for ENVI that can ingest, process, and georeference every known MODIS product (currently 143) through your choice of an easy-to-use interactive widget interface or a fully-accessible programmatic interface.
Download >
ENVI Plugin for Ocean Color (EPOC)
EPOC is an HDF file conversion, reprojection, and georeferencing utility for data sets that are currently distributed through the OceanColor web site or created using the SeaWiFS Data Analysis System.
Download > Documentation >
source information : http://www.ittvis.com/DownloadsHome/toolkits.aspx
What is ENVI?
ENVI is the premier software solution for processing and analyzing geospatial imagery used by GIS professionals, scientists, researchers, and image analysts around the world. ENVI software combines the latest spectral image processing and image analysis technology with an intuitive, user-friendly interface to help you get meaningful information from imagery.
-------------------------------------------------------------------------------------
Toolkits & Plugins
Quickly and easily access toolkits and plug-ins that will empower your IDL and ENVI applications. Each listing here includes code samples and documentation to help you jump start your programming or application development.
The MODIS Conversion Toolkit
The MODIS Conversion Toolkit (MCTK) is plugin for ENVI that can ingest, process, and georeference every known MODIS product (currently 143) through your choice of an easy-to-use interactive widget interface or a fully-accessible programmatic interface.
Download >
ENVI Plugin for Ocean Color (EPOC)
EPOC is an HDF file conversion, reprojection, and georeferencing utility for data sets that are currently distributed through the OceanColor web site or created using the SeaWiFS Data Analysis System.
Download > Documentation >
source information : http://www.ittvis.com/DownloadsHome/toolkits.aspx
Saturday, December 20, 2008
Modis - HDF (Hierarchical Data Format )
MODIS (or Moderate Resolution Imaging Spectroradiometer) is a key instrument aboard the Terra (EOS AM) and Aqua (EOS PM) satellites.
MODIS data in HDF-EOS format (Hierarchical Data Format - Earth Observing System). Hierarchical Data Format (HDF) is the standard data format for all NASA Earth Observing System (EOS) data products. HDF is a multi-object file format developed by The HDF Group.
--
see previous posting about modis tools
--
MODIS Tools is helping us to read, extract or subset, convert HDF-EOS data.
1. MODIS Reprojection Tool (MRT)
a software tool for reading data files in HDF-EOS format, specify a geographic subset or band subset as input to processing, perform geographic transformation to a different coordinate system/cartographic projection, write the output to file formats other than HDF-EOS
Platforms : Unix (Sun, SGI), Windows (9x, 2000, NT, XP), and Linux
2. QA Tools
provides links to QA tools developed for science team and user community
Platforms : Unix
3. HDF Tools
The NCSA HDF Home Page - contains links to an array of HDF support tools and information
Platforms : specific to tool selected
4. HDF-EOS Web-Based Subsetter (HEW)
can extract a subset of any grid or swath data file that is in HDF-EOS format Platforms : independent
5. MODIS Swath-to-Grid Toolbox
a set of software tools that reads HDF-EOS files containing MODIS swath data and produces flat binary files containing gridded data in a variety of map projections Platforms : Unix, with a standard C compiler, also requires Perl 5.0 or higher and IDL 5.0 or higher
6. HDF-EOS to GeoTIFF converter (HEG)
converts many EOS products written in HDF-EOS to GeoTIFF, native binary or HDF-EOS Grid, also has re-projection, resampling, subsetting, stitching (mosaicing), and metadata creation capabilities
Platforms : Linux , Macintosh , SGI , Sun, Windows
7. MODIS Land Tile Calculator
converts latitude/longitude decimal degrees to MODIS Tile grid and Line/Sample coordinates and vice-versa
Platforms: online tool
---
more informations :
- http://modis.gsfc.nasa.gov/
- http://modis-land.gsfc.nasa.gov/tools.htm
- http://nsidc.org/data/hdfeos/
-------------------------------------------------------------------------------------
Membuka atau mengintip isi dari dataset HDF Modis baik Aqua MODIS maupun Terra MODIS, jika menggunakan software berbayar ENVI 4.x bisa dilakukan dengan melalui fasilitas yang tersedia di ENVI 4.x yaitu:
Basic Tools --> Preprocessing --> Data-Specific Utilities --> View HDF Dataset Attributes
kemudian akan muncul window HDF Selection, tentukan HDF dataset yang akan kita lihat, misal Dataset #5 dari data MODIS MYD02HKM...... :
====================================================================================
Dataset #5: Earth View 250M Aggregated 500M Reflective Solar Bands Scaled Integers
Dims: UINT (2708 x 4060 x 2)
Attribute 5-1: "long_name"
"Earth View 250M Aggregated 500M Reflective Solar Bands Scaled Integers"
Attribute 5-2: "units"
"none"
Attribute 5-3: "valid_range"
0, 32767
Attribute 5-4: "_FillValue"
65535
Attribute 5-5: "band_names"
"1,2"
Attribute 5-6: "radiance_scales"
0.02753444, 0.00927813
Attribute 5-7: "radiance_offsets"
-0.00000000, -0.00000000
Attribute 5-8: "radiance_units"
"Watts/m^2/micrometer/steradian"
Attribute 5-9: "reflectance_scales"
0.00005396, 0.00002950
Attribute 5-10: "reflectance_offsets"
-0.00000000, -0.00000000
Attribute 5-11: "reflectance_units"
"none"
Attribute 5-12: "corrected_counts_scales"
0.12497330, 0.12497330
Attribute 5-13: "corrected_counts_offsets"
-0.00000000, -0.00000000
Attribute 5-14: "corrected_counts_units"
"counts"
====================================================================================
Informasi di atas, seperti radiance dan reflectance baik scale dan offset itulah yang akan digunakan untuk koreksi radiometrik dari data MODIS yang akan kita gunakan.
------------------------------------------------------------------------------------
Selain menggunakan software image processing ENVI 4.x, kita juga bisa menggunakan software-software viewer data HDF, misalnya HDF Explorer
HDF Explorer ini dibuat oleh
Space Research Software, Inc, headquartered in the heart of the Silicon Prairie in Urbana-Champaign, Illinois, is a leading company in HDF related visualization tools. Its flagship product HDF Explorer, is a widely acclaimed software tool that allows an easy browsing of HDF data files.
-------------------------------
HDF Explorer is a data visualization program that reads the HDF, HDF5 and netCDF data file formats. HDF Explorer runs in the Microsoft Windows operating systems. Check this page (http://www.space-research.org/) for version updates, current version is 1.4.025
--------------------------------
HDF (Hierarchical Data Format) is a library and platform independent data format for the storage and exchange of scientific data. HDF is developed and supported by the HDF group
====================================================================================
Membuka atau mengintip isi dari dataset HDF Modis baik Aqua MODIS maupun Terra MODIS, jika menggunakan software HDF Explorer :
====================================================================================
====================================================================================
more information about HDF Explorer : http://www.space-research.org/
***********************************************************************************
salam rsgis,
Aji Putra Perdana
http://ajiputrap.blogspot.com/
MODIS data in HDF-EOS format (Hierarchical Data Format - Earth Observing System). Hierarchical Data Format (HDF) is the standard data format for all NASA Earth Observing System (EOS) data products. HDF is a multi-object file format developed by The HDF Group.
--
see previous posting about modis tools
--
MODIS Tools is helping us to read, extract or subset, convert HDF-EOS data.
1. MODIS Reprojection Tool (MRT)
a software tool for reading data files in HDF-EOS format, specify a geographic subset or band subset as input to processing, perform geographic transformation to a different coordinate system/cartographic projection, write the output to file formats other than HDF-EOS
Platforms : Unix (Sun, SGI), Windows (9x, 2000, NT, XP), and Linux
2. QA Tools
provides links to QA tools developed for science team and user community
Platforms : Unix
3. HDF Tools
The NCSA HDF Home Page - contains links to an array of HDF support tools and information
Platforms : specific to tool selected
4. HDF-EOS Web-Based Subsetter (HEW)
can extract a subset of any grid or swath data file that is in HDF-EOS format Platforms : independent
5. MODIS Swath-to-Grid Toolbox
a set of software tools that reads HDF-EOS files containing MODIS swath data and produces flat binary files containing gridded data in a variety of map projections Platforms : Unix, with a standard C compiler, also requires Perl 5.0 or higher and IDL 5.0 or higher
6. HDF-EOS to GeoTIFF converter (HEG)
converts many EOS products written in HDF-EOS to GeoTIFF, native binary or HDF-EOS Grid, also has re-projection, resampling, subsetting, stitching (mosaicing), and metadata creation capabilities
Platforms : Linux , Macintosh , SGI , Sun, Windows
7. MODIS Land Tile Calculator
converts latitude/longitude decimal degrees to MODIS Tile grid and Line/Sample coordinates and vice-versa
Platforms: online tool
---
more informations :
- http://modis.gsfc.nasa.gov/
- http://modis-land.gsfc.nasa.gov/tools.htm
- http://nsidc.org/data/hdfeos/
-------------------------------------------------------------------------------------
Membuka atau mengintip isi dari dataset HDF Modis baik Aqua MODIS maupun Terra MODIS, jika menggunakan software berbayar ENVI 4.x bisa dilakukan dengan melalui fasilitas yang tersedia di ENVI 4.x yaitu:
Basic Tools --> Preprocessing --> Data-Specific Utilities --> View HDF Dataset Attributes
kemudian akan muncul window HDF Selection, tentukan HDF dataset yang akan kita lihat, misal Dataset #5 dari data MODIS MYD02HKM...... :
====================================================================================
Dataset #5: Earth View 250M Aggregated 500M Reflective Solar Bands Scaled Integers
Dims: UINT (2708 x 4060 x 2)
Attribute 5-1: "long_name"
"Earth View 250M Aggregated 500M Reflective Solar Bands Scaled Integers"
Attribute 5-2: "units"
"none"
Attribute 5-3: "valid_range"
0, 32767
Attribute 5-4: "_FillValue"
65535
Attribute 5-5: "band_names"
"1,2"
Attribute 5-6: "radiance_scales"
0.02753444, 0.00927813
Attribute 5-7: "radiance_offsets"
-0.00000000, -0.00000000
Attribute 5-8: "radiance_units"
"Watts/m^2/micrometer/steradian"
Attribute 5-9: "reflectance_scales"
0.00005396, 0.00002950
Attribute 5-10: "reflectance_offsets"
-0.00000000, -0.00000000
Attribute 5-11: "reflectance_units"
"none"
Attribute 5-12: "corrected_counts_scales"
0.12497330, 0.12497330
Attribute 5-13: "corrected_counts_offsets"
-0.00000000, -0.00000000
Attribute 5-14: "corrected_counts_units"
"counts"
====================================================================================
Informasi di atas, seperti radiance dan reflectance baik scale dan offset itulah yang akan digunakan untuk koreksi radiometrik dari data MODIS yang akan kita gunakan.
------------------------------------------------------------------------------------
Selain menggunakan software image processing ENVI 4.x, kita juga bisa menggunakan software-software viewer data HDF, misalnya HDF Explorer
HDF Explorer ini dibuat oleh
Space Research Software, Inc, headquartered in the heart of the Silicon Prairie in Urbana-Champaign, Illinois, is a leading company in HDF related visualization tools. Its flagship product HDF Explorer, is a widely acclaimed software tool that allows an easy browsing of HDF data files.
-------------------------------
HDF Explorer is a data visualization program that reads the HDF, HDF5 and netCDF data file formats. HDF Explorer runs in the Microsoft Windows operating systems. Check this page (http://www.space-research.org/) for version updates, current version is 1.4.025
--------------------------------
HDF (Hierarchical Data Format) is a library and platform independent data format for the storage and exchange of scientific data. HDF is developed and supported by the HDF group
====================================================================================
Membuka atau mengintip isi dari dataset HDF Modis baik Aqua MODIS maupun Terra MODIS, jika menggunakan software HDF Explorer :
====================================================================================
====================================================================================more information about HDF Explorer : http://www.space-research.org/
***********************************************************************************
salam rsgis,
Aji Putra Perdana
http://ajiputrap.blogspot.com/
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