190 likes | 293 Vues
This tool offers easy access to MODIS land products, allowing users to validate remote sensing products, characterize field sites, and perform trend analysis. Key features include data in ASCII and GeoTIFF formats, subsetting capabilities for any location on Earth, and tools for scientific research, classroom education, GIS overlay analysis, and statistical analysis across different land cover types.
E N D
MODIS Land Product Subsets Suresh K. SanthanaVannan, Robert B. Cook, Bruce E. Wilson, Lisa M. Olsen HDF and HDF-EOS Workshop XII October 15 – October 17, 2008 ORNL DAAC Oak Ridge National Laboratory Distributed Active Archive Center Oak Ridge, Tennessee, USA
What is MODIS • MODerate Resolution Imaging Spectroradiometer • Hyper-Spectral sensor onboard two satellites (Terra and Aqua) • Terra MODIS and Aqua MODIS are viewing the entire Earth's surface every 1 to 2 days, acquiring data in 36 spectral bands, or groups of wavelengths • Data stored in HDF-EOS gridded file format Source : http://aqua.nasa.gov
MODIS is great! but …….. Users (Field researchers) have some inconveniences :
Accessibility • Data Format • Processing Time
What ORNL-DAAC offers? User community requested that we prepare MODIS Land Products in an easy-to-use format and size • To validate remote sensing products • To characterize field sites
Tools Used • hdp dumpsds from The HDF group • Customized for our need • MODIS Reprojection tool from LPDAAC • GDAL (Geospatial Data Abstraction Library) • Minnesota Map server • Custom Perl code
MODIS Subsets for Selected sites Data Formats Offered • ASCII – 7x7 km subsets • GeoTIFF – 25x25 km subsets
Subsetting and Visualization Tool for Any location on Globe Demo: http://daac.ornl.gov/modisglobal
1975 2001
1975 2001 2000 2008
MODIS Subsetting Web Service f(x) SOAP Client Server ################# ORNL DAAC MODIS Web service - Perl client#################use SOAP::Lite@params= SOAP::Lite -> service(‘WSDL_URL') -> xmlschema('http://www.w3.org/2001/XMLSchema') -> getsubset(lat,lon,product,start_date,end_date,size); MOD11A2.A2003001.h26v05.005.2007264203857.Clear_sky_days,MOD11A2,A2003001,Lat37.7Lon110Samp1Line1,2007264203857,Clear_sky_days,NA,0.000,2 MOD11A2.A2003001.h26v05.005.2007264203857.Clear_sky_nights,MOD11A2,A2003001,Lat37.7Lon110Samp1Line1,2007264203857,Clear_sky_nights,NA,0.000,254 …….
Scope • Tool for scientific research (Environmental Impact assessment, carbon budgeting, etc.) • Classroom education and projects for students • Time series, trend analysis • GIS overlay analysis • Statistical analysis (Across many years and across different land cover types) • Validation of MODIS products and other remote sensing products
Questions? Links • http://www.modis.ornl.gov/modis/index.cfm • http://daac.ornl.gov/MODIS/modis.html