Global Temperature-Salinity Profile Program. R-GIS. ModisDownload: an R function to download, mosaic, and reproject the MODIS images Babak Naimi [ModisDownload.R has been updated to version 3.2 on 2014.01.13, 10:45 GMT] MODIS instruments including two satellites (Terra and Aqua) are viewing the entire earth surface every 1 to 2 days, acquiring 36 spectral bands.
These data provide insight on global processes occurring on the land, ocean and atmosphere. The images ranging in wavelength from 0.4 µm to 14.4 µm, at spatial resolutions of 250, 500, and 1000 m. You can find an overview and more details on image specifications here. This page introduces you an implemented function in R that can be used to download, mosaic and reproject of MODIS images from Land processes distributed active archive center (LP DAAC). What does ModisDownload offer? ‘ModisDownload’ downloads a series of images in a specific date or a date range and in specified tile(s). Instructions to use ModisDownload: In order to use ModisDownload, you first need: Arguments listfiles. Installing MODIS for R | Steven Mosher's Blog. If you have installed MRT and OsGeow4, and reviewed the Modis data on datapool, then you are ready for the next step: Installing MODIS package.
At the current writing the package is not posted to CRAN, that will happen in due course. If you want to get started, then, you’ll have to install it from source using bits available at R Forge. Before I show you how to do that, let me pull up the description file from the package Package: MODIS Version: 0.6-22 Date: 16-November-2012 Title: MODIS download and processing package. Processing functionalities for (multi-temporal) MODIS grid data. The package description lets us know what other packages we are going to have to install first to make the MODIS R package work. The only packages that might be a bit tricky to install are RCurl, and SSOAP. In my current testing I havent been able to get any of the calls that rely on SSOAP to work, so I’ll be making bug reports. SSOAP resides here. With the file unzipped, you now use your windows console. Download and resampling of MODIS images - spatial-analyst.net.
His article explains how to automate download, mosaicking, resampling and import of MODIS product to a GIS. We focus on the one of the most known MODIS products for terrestrial environmental applications: the Enhanced Vegetation Index (EVI), which is the improved NDVI (Huete et al., 2002; see the complete list of MODIS products). EVI corrects distortions in the reflected light caused by the particles in the air as well as the ground cover below the vegetation.
The EVI also does not become saturated as easily as the NDVI when viewing rainforests and other areas with large amounts of chlorophyll. EVI can be directly related to the photosynthetic production of plants, and indirectly to the green biomass (Huete et al., 2002). By observing dynamics of EVI for an area of Earth's surface, we can infer about the vegetation dynamics within season, but also detect long-term trends and sudden changes in the biomass (e.g. due to forest fires, deforestation, urban growth and similar). References. Oceancolor Data. Prosope-dms. ORNL DAAC Data. EROS Find Data/Products and Data Available/Tri-Decadal Global Landsat Orthorectified Overview. ASTER: Advanced Spaceborne Thermal Emission and Reflection Radiometer. Landsat Science - Data. The Numbers Behind Landsat All Landsat data in the USGS archive are now free! + Watch live as Landsat data are collected Landsat sensors record reflected and emitted energy from Earth in various wavelengths of the electromagnetic spectrum.
The electromagnetic spectrum includes all forms of radiated energy from tiny gamma rays and x-rays all the way to huge radio waves. The human eye is sensitive to the visible wavelenghs of this spectrum; we can see color, or reflected light, ranging from violet to red. Today, Landsats 7 and 8 “see” and record blue, green, and red light in the visible spectrum as well as near-infrared, mid-infrared, and thermal-infrared light that human eyes cannot perceive (although we can feel the thermal-infrared as heat).
Landsat records this information digitally and it is downlinked to ground stations, processed, and stored in a data archive. It is this digital information that makes remotely sensed data invaluable. USGS EO-1 Website - Giovanni - Interactive Visualization and Analysis — GES DISC: Goddard Earth Sciences, Data & Information Services Center. Info Contributors: tonyr, rchowdhury Giovanni - Interactive Visualization and Analysis - GES DISC: Goddard Earth Sciences, Data and Information Services Center Giovanni-4 Now Available New!
Please try out Giovanni-4, the next generation of Giovanni, with dramatically improved performance and interactive plotting and mapping. (Currently, only select Aerosols, Hydrology and Turbulent Flux data are available in Giovanni-4, with more on the way.) Scan Giovanni parameter data and associated portals in the table below. The parameter data can be filtered and sorted (click a column header to sort)`. Loading parameters... Giovanni is a Web application developed by the GES DISC to provide a simple, intuitive way to visualize, analyze, and access vast amounts of Earth science remote sensing data, particularly from satellites, without having to download the data. Giovanni consists of several portals tailored to meet the needs of different Earth science research communities.