This data set contains the Moderate Resolution Imaging Spectroradiometer (MODIS) Airborne Simulator (MAS) multispectral data collected during the SAFARI 2000 project. Twenty flights with the MAS instrument were undertaken over Southern Africa by the NASA ER-2 aircraft during August and September, 2000. The MAS spectrometer collects 50 multispectral bands at 16-bit resolution with a ground resolution of 50 meters from 20,000 meters altitude and a cross track scan width of 85.92 degrees.
The MODIS Airborne Simulator (MAS) is an airborne scanning spectrometer that acquires high spatial resolution imagery of cloud and surface features from its vantage point on-board a NASA ER-2 high-altitude research aircraft [http://ladsweb.nascom.nasa.gov/data/MAS.html ]. Data acquired by the MAS are helping to define, develop, and test algorithms for MODIS, a key sensor of NASA's Earth Observing System (EOS). The MODIS program [http://modis.gsfc.nasa.gov/] emphasizes the use of remotely sensed data to monitor variation in environmental conditions for assessing both natural and human-induced global change.
This data set is organized by flight. Each flight consists of several straight-line segments called tracks. There is MAS multispectral data file for each track. The data are available in Hierarchical Data Format (HDF). Additional companion images and documentation include; flight track maps, browse images, sample RGB images, configuration files, and the ER-2 flight logs. An automated interface in the DAAC Search and Order system facilitates ordering data for selected tracks from any of the flights and provides ready access to flight documentation and browse images.
Cite this data set as follows:
King, M. D., and S. E. Platnick. 2006. SAFARI 2000 MODIS Airborne Simulator Data, Southern Africa, Dry Season 2000. Data set. Available on-line [http://daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A.
King, M. D., W. P. Menzel, P. S. Grant, J. S. Myers, G. T. Arnold, S. E. Platnick, L. E. Gumley, S. C. Tsay, C. C. Moeller, M. Fitzgerald, K. S. Brown and F. G. Osterwisch, 1996: Airborne scanning spectrometer for remote sensing of cloud, aerosol, water vapor and surface properties. J. Atmos. Oceanic Technol., 13, 777-794.
MAS Level-1B data are stored in Hierarchical Data Format, version 4, (HDF4). HDF is a multi-object file format for the transfer of graphical and numerical data between machines that allows the user to create, access, and share scientific data in a form that is self-describing and network-transparent. Self-describing means that a file includes information defining the data it contains. Network-transparent means that a file is represented in a form that can be accessed by computers with different ways of storing integers, characters, and floating-point numbers. For HDF tools and additional information about the MAS data see the MAS Home Page [http://ladsweb.nascom.nasa.gov/data/MAS.html ]. Free FORTRAN & C programs to unpack MAS Level-1B HDF4 files are available [http://mas.arc.nasa.gov/reference/unpacking.html ].
The SAFARI 2000 MAS data set contains 146 GB of data. Individual HDF files for a flight track may exceed the size of a CD and are best written to DVD. In general, there are between 10 and 20 straight line flight tracks in a given flight. You may use the automated interface to order data from selected tracks (flight segments). If you require larger portions of this data, we recommend that you contact us by email or phone and make special arrangements.
All SAFARI 2000 MAS flight data have been fully processed with final calibrations. As background for each flight, a companion file with flight line summary and calibration information is provided (MAS_flight_summary_SUM.tar.gz) and also a companion file of MAS band configuration, calibration, and correction information (MAS_configuration_CFG.tar.gz) are provided. The referenced files of spectral response measurements are included in a separate companion file (MAS_calibration_SRF.tar.gz).
Also, the complete data subsetting and ordering interface web site for each flight (including flight track maps, browse images, sample RGB images, configuration files, and the ER-2 flight logs) has been converted to a *.pdf file companion file for user documentation convenience. In addition, all of the .gif and .jpg flight images used in the ordering interface are provided in their full resolution as a companion file (MAS_images.tar.gz).