The moderate resolution imaging spectrometer: An EOS facility instrument candidate for application of data compression methods

The Moderate Resolution Imaging Spectrometer (MODIS) observing facility will operate on the Earth Observing System (EOS) in the late 1990's. It is estimated that this observing facility will produce over 200 gigabytes of data per day requiring a storage capability of just over 300 gigabytes per day. Archiving, browsing, and distributing the data associated with MODIS represents a rich opportunity for testing and applying both lossless and lossy data compression methods

Global resources and mission to planet earth

The NASA contribution to the U.S. Global Change Research Program is termed the Mission to Planet Earth. Components of the Mission to Planet Earth, such as the Upper Atmosphere Research Satellite (UARS), have already been flown; and several other satellites will be flown in the next few years. The major component of the Mission to Planet Earth is the Earth Observing System (EOS) scheduled for initial launch in 1998. Considerable volumes of valuable data will be stored and made accessible through the EOS Data and Information System and environmental impact studies. The challenges in making these data available are to provide the technologies and infrastructure to make them accessible to scientists, resource managers, and decision-makers in a timely and cost-effective fashion. In addition, students must be trained and given the background to make optimal use of remotely sensed data, such as that forthcoming from space borne observing platforms

Fractional Snowcover Estimates from Earth Observing System (EOS) Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS)

The Moderate Resolution Imaging Spectroradiometer (MODIS) on the NASA Earth Observing System (EOS) Terra and Aqua missions has shown considerable capability for mapping snowcover. The typical approach that has used, along with other criteria, the Normalized Snow Difference Index (NDSI) that takes the difference between 500 meter observations at 1.64 micrometers (MODIS band 6) and 0.555 micrometers (MODIS band 4) over the sum of these observations to determine whether MODIS pixels are snowcovered or not in mapping the extent of snowcover. For many hydrological and climate studies using remote sensing of snowcover, it is desirable to assess if the MODIS snowcover observations could not be enhanced by providing the fraction of snowcover in each MODIS observation (pixel). Pursuant to this objective studies have been conducted to assess whether there is sufficient "signal%o in the NDSI parameter to provide useful estimates of fractional snowcover in each MODIS 500 meter pixel. To accomplish this objective high spatial resolution (30 meter) Landsat snowcover observations were used and co-registered with MODIS 500 meter pixels. The NDSI approach was used to assess whether a Landsat pixel was or was not snowcovered. Then the number of snowcovered Landsat pixels within a MODIS pixel was used to determine the fraction of snowcover within each MODIS pixel. The e results were then used to develop statistical relationships between the NDSI value for each 500 meter MODIS pixel and the fraction of snowcover in the MODIS pixel. Such studies were conducted for three widely different areas covered by Landsat scenes in Alaska, Russia, and the Quebec Province in Canada. The statistical relationships indicate that a 10 percent accuracy can be attained. The variability in the statistical relationship for the three areas was found to be remarkably similar (-0.02 for mean error and less than 0.01 for mean absolute error and standard deviation). Independent tests of the relationships were accomplished by taking the relationship of fractional snow-cover to NDSI from one area (e.g., Alaska) and testing it on the other two areas (e.g. Russia and Quebec). Again the results showed that fractional snow-cover can be estimated to 10 percent. The results have been shown to have advantages over other published fractional snowcover algorithms applied to MODIS data. Most recently the fractional snow-cover algorithm has been applied using 500-meter observations over the state of Colorado for a period spanning 25 days. The results exhibit good behavior in mapping the spatial and temporal variability in snowcover over that 25-day period. Overall these studies indicate that robust estimates of fractional snow-cover can be attained using the NDSI parameter over areas extending in size from watersheds relatively large compared to MODIS pixels to global land cover. Other refinements to this approach as well as different approaches are being examined for mapping fractional snow-cover using MODIS observations

Aqua MODIS Thermal Emissive Band On-Orbit Calibration, Characterization, and Performance

The NASA's Earth Observing System Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) has continued to operate with satisfactory performance since its launch in May 2002, exceeding its nominal six-year design lifetime. Its continuous Earth observations have been used to generate many science data products for studies of the Earth's, system. MODIS has 36 spectral bands; 20 reflective solar bands and 16 thermal emissive bands (TEBs). All TEB observations are made at 1-km nadir spatial resolution with spectral wavelengths from 3.7 to 14.4 pm. Primary applications of MODIS TEB 'include surface, cloud, and atmospheric temperatures, water vapor, and cloud top altitude. MODIS TEB on-orbit calibration uses a quadratic algorithm with its calibration coefficients derived using an onboard blackbody (BB). This paper will present Aqua MODIS TEB on-orbit calibration, characterization, and performance over its six-year mission. Examples of instrument thermal behavior, BB temperature stability, detector short-term stability, and changes in long-term response (or system gain) will be presented. Comparisons will also be made with Terra MODIS, launched in December 1999. On-orbit results show that Aqua MODIS and its focal plane temperatures have behaved normally. BB temperature has remained extremely stable with typical scan -to-scan variations of less than +/-0.15 mK. Most TEB detectors continue to exceed their specified signal-to-noise ratio requirements, exhibiting excellent short-term stability and calibration accuracy. Excluding a few noisy detectors, either identified prelaunch or occurring postlaunch, on-orbit changes in TEB responses have been less than 0.5% on an annual basis. By comparison; the overall Aqua TEB performance has been better than that of Terra MODIS

An Overview of the Landsat-D Project with Emphasis on the Flight Segment

In the third quarter of 1981, a new, experimental Earth-resources monitoring system, Landsat-D, is scheduled for launch. The characteristics of this system have been under consideration since about 1970 through a series of study efforts and with the guidance of several advisory groups composed of representatives of federal, state, and local agencies, private industry, and university personnel. From these studies and efforts evolved an Earth resources monitoring system, Landsat-D, that includes several technological advances over the capabilities provided by Landsats 1, 2, and 3. In essence, the Landsat-D system is designed to be a complete, highly automated data gathering and processing system that should substantially contribute to more effective remote sensing of Earth resources and to the management of these resources on a local, regional, continental, and global basis

Experiences using MODIS Data to monitor environmental and snow cover conditions over the Great Salt Lake Basin and sub-basins

The Moderate Resolution Imaging Spectroradiometer (MODIS) on the NASA Earth Observing System (EOS) Terra and Aqua Missions makes daily, global observations in 36 spectral bands with spatial resolutions between 250-1000 meters. Recently research on applying MODIS observations over the entire Great Salt Lake Basin has begun with emphasis on observing snow cover and other environmental conditions with special attention to the distribution in time and space of snow cover. For snow cover there are MODIS daily, geolocated swath (level 2) products covering the basin at 500 meters. Additionally there are eight-day, 500m, level-3, gridded snow cover products that provide cloud-free observations of snow cover. Also MODIS surface reflectance, land cover, surface temperature, and albedo observations have been obtained upon which the boundaries of the entire Great Salt Lake Basin and the several sub-basins have been superimposed. Several snow cover products have been acquired for the winter/spring period of 2001 showing the capability to monitor snow cover temporal changes. Present challenges posed by slope, aspect, and land cover are being assessed relative to their impact on making accurate useful snow cover estimates. The ultimate objective is to assess MODIS products relative to their utility in obtaining improved basin runoff estimates

Anisotropy in reflected solar radiation

August, 1968.Includes bibliographical references (pages 121-126).Sponsored by the National Aeronautics and Space Administration NASr-147

Snow and Ice Products from the Moderate Resolution Imaging Spectroradiometer

Snow and sea ice products, derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument, flown on the Terra and Aqua satellites, are or will be available through the National Snow and Ice Data Center Distributed Active Archive Center (DAAC). The algorithms that produce the products are automated, thus providing a consistent global data set that is suitable for climate studies. The suite of MODIS snow products begins with a 500-m resolution, 2330-km swath snow-cover map that is then projected onto a sinusoidal grid to produce daily and 8-day composite tile products. The sequence proceeds to daily and 8-day composite climate-modeling grid (CMG) products at 0.05 resolution. A daily snow albedo product will be available in early 2003 as a beta test product. The sequence of sea ice products begins with a swath product at 1-km resolution that provides sea ice extent and ice-surface temperature (IST). The sea ice swath products are then mapped onto the Lambert azimuthal equal area or EASE-Grid projection to create a daily and 8-day composite sea ice tile product, also at 1 -km resolution. Climate-Modeling Grid (CMG) sea ice products in the EASE-Grid projection at 4-km resolution are planned for early 2003