The National Aeronautics and Space Administration (NASA) Landsat program has been dedicated to sustaining data continuity over the 20-year period during which Landsat Thematic Mapper (TM) and Enhanced TM Plus (ETM+) sensors have been acquiring images of the earth's surface. In 2000, NASA launched the Earth Observing-1 (EO-1) Advanced Land Imager (ALI) to test new technology that could improve t...

An atmospheric correction tool has been developed for public web site access for the Landsat-5 and Landsat-7 thermal band. The Atmospheric Correction Parameter Calculator uses the National Centers for Environmental Prediction (NCEP) modeled atmospheric global profiles for a particular date, time and location as input. Using commercially-available MODTRAN software and a suite of integration algo...

The Landsat-7 ETM+ sensor offers several enhancements over the Landsat-4,5 Thematic Mapper (TM) sensor, including increased spectral information content, improved geodetic accuracy, reduced noise, reliable calibration, the addition of a panchromatic band, and improved spatial resolution of the thermal band. In this paper, we present some initial comparisons between Landsat-5 TM and Landsat-7 ET...

a knowledge of soil surface conditions, especially desert crust, salt crust and desert varnish is useful for improving classification of remotely sensed data. desert crust can generate high levels of reflectance, similar to those areas with high salt concentration and non-saline soil. therefore, soil surface crusts might bias thematic remote sensing of soils. in this study, we evaluated the eff...

Early in its mission, the Landsat-7 spacecraft was temporarily placed in a ‘‘tandem’’ orbit very close to that of the Landsat-5 spacecraft in order to facilitate the establishment of sensor calibration continuity between the Landsat-7 Enhanced Thematic Mapper Plus (ETM+) and Landsat-5 Thematic Mapper (TM) sensors. The key period for the tandem configuration was June 1–4, 1999, during which hund...

A C++ language-based software tool for retrieving land surface temperature (LST) from the data of Landsat TM/ ETM+ band6 is developed. It has two main functional modules: (1) Three methods to compute the ground emissivity based on land use/cover classification image, NDVI image and the ratio values of vegetation and bare ground and (2) Converting digital numbers (DNs) from TM/ETM+ band6 to LST....

The Earth Observation for Sustainable Development of Canada’s forests (EOSD) project monitors Canada's forests from space. Canada contains ten-percent of the world’s forests. Initial EOSD products are land cover, forest change, forest biomass, and automated methods. There are more than 500 LANDSAT TM or ETM+ scenes required for a single coverage of Canada’s forests. Multi-temporal analysis usin...

AIMS The aim of the ab externo trabeculectomy (AET) is to remove the external portion of the trabecular meshwork (ETM) responsible for the main aqueous outflow resistance in glaucoma patients, with no opening of the anterior chamber. ETM characteristics were evaluated with a confocal microscope. METHODS A prospective comparative observational case series was performed in 60 consecutive medica...

The recent launch of Landsat-7 ETM+ extends the uninterrupted stream of TM and ETM+ images to a potential span of 32 years. This exceptional image set will allow long-term studies of natural resources, but will require an operational method for converting image digital number (dn) to the temporally comparable surface reflectance factor (rsl). A refinement to the empirical line (EL) approach for...

The ability to detect and quantify changes in the Earth’s environment depends on satellites sensors that can provide calibrated, consistent measurements of Earth’s surface features through time. A critical step in this process is to put image data from subsequent generations of sensors onto a common radiometric scale. To evaluate Landsat-5 (L5) Thematic Mapper’s (TM) utility in this role, image...