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At least 559 records · Page 31
All sourcesNASA NTRSDOE OSTI
NASA NTRS1981

Information expectations from Landsat-D

The first satellite of the Landsat-D Project is to be launched in the third quarter of 1982 with a second satellite to be prepared for launch 12 to 15 months later. Both spacecraft are to include the familiar Multispectral Scanner (MSS) and the advanced multispectral scanner called the Thematic Mapper (TM). The ground data processing system for the MSS data is to be ready to produce 200 scenes a day in 1982. The data processing systems for the TM are to be fully operational at the 50 to 100 scenes a day level in early 1985. The fabrication of the system components has proceeded well in recent months, and integration of the total system is under way. The procedures for processing the data and meeting specifications are nearly completed for the MSS and are outlined in detail for the TM. An outline of an investigation program stressing systems performance has been developed for the period 1982 to 1985.

Salomonson, V. V.↗
NASA NTRS1982

The Landsat-D responsiveness to user community needs

Initial examinations of the Landsat-4 Multispectral Scanner and Thematic Mapper (IM) imagery indicate that these systems and the ground-based data processing systems are performing well. A combination of the spatial resolution of the multispectral scanner with the four band (0.5-0.6, 0.6-0.7, 0.7-0.8, and 0.8-1.1 microns) multispectral capability provides a useful observation technique for identifying crop type, phenological state of development, and a real condition assessment. Landsat multispectral scanner imagery has become more important in the search for new deposits of oil and mineral resources, and geological applications indicate that image analysis complements geological mapping techniques. Advantages of the TM include more precise measurements of the increased reflectance of vegetation in the green and near infrared. In addition, TM has improvement vegetation species differentiation, due to measurements made in new spectral bands. Preliminary TM data analysis reveals that systems have performed to optimum expectations.

Salomonson, V. V.↗
NASA NTRS1983

AN-A46: LANDSAT scene-to-scene registration assessment

LANDSAT-4 MSS data and TM data for the 16 September 1982 scene were received. MSS data were reformatted and scene to scene registration, with previous MSS data is nearing completion. LANDSAT-2 to LANDSAT-2 MSS registration was completed. The results obtained serve as a baseline against which to compare the registrations containing LANDSAT-4 MSS. The TM data set as originally processed for the Orleans area had excessive yaw which exaggerated the forward/reverse scan pixal alignment, GSFC software was subsequently modified to minimize the problem. A detector stitching problem most pronounced in bodies of water was noted for TM channel 3 (0.63 micrometer to 0.69 micrometer).

Anderson, J. E.↗
NASA NTRS1981

Potential utility of the thematic mapper for surface mine monitoring

One of many potential applications of the thematic mapper (TM) is surface mine monitoring. To assess this potential, data acquired by an aircraft multispectral scanner over Pennsylvania surface mines were preprocessed to simulate the anticipated spectral, spatial, and radiometric characteristics of TM data. False color imagery and thematic maps were derived from the simulated data and compared to imagery and maps derived from LANDSAT multispectral scanner subsystems data. On the basis of this comparison, TM data should definitely increase the detail and accuracy of remotely acquired surface mine information and may enable the remote determination of compliance with reclamation regulations.

Irons, J. R.↗
NASA NTRS1983

LANDSAT-4 image data quality analysis

Analysis during the quarter was carried out on geometric, radiometric, and information content aspects of both MSS and thematic mapper (TM) data. Test sites in Webster County, Iowa and Chicago, IL., and near Joliet, IL were studied. Band to band registration was evaluated and TM Bands 5 and 7 were found to be approximately 0.5 pixel out of registration with 1,2,3,4, and the thermal was found to be misregistered by 4 30 m pixels to the east and 1 pixel south. Certain MSS bands indicated nominally .25 pixel misregistration. Radiometrically, some striping was observed in TM bands and significant oscillatory noise patterns exist in MSS data which is possibly due to jitter. Information content was compared before and after cubic convolution resampling and no differences were observed in statistics or separability of basic scene classes.

Anuta, P. E.↗
NASA NTRS1983

Study of LANDSAT-D thematic mapper performance as applied to hydrocarbon exploration

Improved delineation of known oil and gas fields in southern Ontario and a spectacularly high amount of structural information on the Owl Creek, Wyoming scene were obtained from analysis of TM data. The use of hue, saturation, and value image processing techniques on a Death Valley, California scene permitted direct comparison of TM processed imagery with existing 1:250,000 scale geological maps of the area and revealed small outcrops of Tertiary volcanic material overlying Paleozoic sections. Analysis of TM data over Lawton, Oklahoma suggests that the reducing chemical environment associated with hydrocarbon seepage change ferric iron to soluble ferrous iron, allowing it to be leached. Results of the band selection algorithm show a suprising consistency, with the 1,4,5 combination selected as optimal in most cases.

Everett, J. R.↗
NASA NTRS1983

An evaluation of LANDSAT-4 thematic mapper data for their geometric and radiometric accuracies and their relevance to geologic mapping

Thematic mapper scenes for Washington, D.C. and Macon, Georgia were examined to determine their radiometry and geometric accuracy. Specific band ratios were used to determine their effectiveness in defining vegetation and rock mineralogy. the TM 3/4 band ratio was used to define vegetation and the 5/2 band ratio was used to define limonitic rocks. The 5/7 band ratio was evaluated to test the effectiveness of the 1.6 and 2.2 mm bands in detecting clay and carbonate bearing rocks. Preliminary results show that clay minerals containing absorption bands at 2.2 mm, which are centered in the TM band 7, can be readily detected when the band ratio images are suitably contrast stretched. Bright rocks, such as marbles, which contain absorption bands in the 2.33 mm region, near the wavelength of TM band 7, are only evident upon harsher contrast stretching of the 5/7 band ratio. Geobotanical studies of Washington, D.C. show that monospecific forest canopies can be differentiated.

Bender, L. U.↗
NASA NTRS1983

Evaluation of spatial, radiometric and spectral thematic mapper performance for coastal studies

Radiative transfer theory was used to model upwelling radiance for an orbiting sensor viewing an estuarine environment. Radiance was calculated in Tm bands 3,4, and 5 and MSS bands 4 and 5 for an optically shallow estuary of either clear or turbid water, and of three bottom types: vegetation, sand, or mud. A portion of a TM image of Chesapeake Bay was enhanced to obtain a quick look at what submerged features could be detected. The enhancements were compared with low altitude color aerial photography. The TM bands 1,2, and 3 were found to contain water and submerged features information. Band 1 contained a significant amount of noise and low contrast. Band 2 appeared to contain the most amount of bottom information. Band 3, while having the least amount of noise and best constrast, contained a lesser amount of bottom information because of increase water absorption. Several water signatures were identified which correlated with submerged vegetation shown in the aerial photography.

Klemas, V.↗
NASA NTRS1983

Spectroradiometric calibration of the thematic mapper and multispectral scanner system

The results obtained for the absolute calibration of TM bands 2, 3, and 4 are presented. The results are based on TM image data collected simultaneously with ground and atmospheric data at White Sands, New Mexico. Also discussed are the results of a moments analysis to determine the equivalent bandpasses, effective central wavelengths and normalized responses of the TM and MSS spectral bands; the calibration of the BaSO, plate used at White Sands; and future plans.

Slater, P. N.↗
NASA NTRS1982

Landsat-D, about to be reality

The space and ground segments of the Landsat-D thematic mapper (TM) for remote sensing of a 185 km swath with 30 m resolution are described. Scanning the full earth once every 16 days from its 705 km sunsynchronous orbit, Landsat-D will relay its data on the ku-band through the TDRSS satellite to a ground station. The X-band will also be used to transmit data directly to foreign and domestic ground stations; the S-band will be reserved for MSS data only. Landsat-D comprises the multimission modular spacecraft and the instrument module, which features the MSS and TM, a wideband communication subsystem, a solar array, and an L-band global positioning system. Three computers on the ground provide a high degree of automation for reception, storage, retrieval, back-up, and transmission of data and commands. Additionally, a van is equipped with transportable equipment, including an antenna. Procedures followed for image generation from the MSS and TM are detailed, noting storage at Goddard until dispersal of tapes under the direction of the EROS data center.

Aepli, T. C.↗
NASA NTRS1983

Evaluation of spatial, radiometric and spectral thematic mapper performance for coastal studies

An area along the southeastern shore of the Chesapeake Bay was subsetted from TM imagery. The subsetted image was then enhanced and classified using an ERDAS 400 system. Results obtained were compared with a chart showing the distribution of both Zolsters marina and Rupplia martime in the Vaucluse Shores and which supports a large community of SAV. Radiative transfer models describing the irradiance reflectance of a water column containing SAV are being refined. Radiative transfer theory was used to model upwelling radiance for an orbiting sensor viewing an estuarine environment. Upwelling radiance was calculated for a clear maritime atmosphere, an optically shallow estuary of either clear or turbid water, and one of three bottom types: vegetation, sand, or mud using TM bands 1, 2, and 3 and MSS bands 4 and 5. A spectral quality index was defined similar to the equation for apparent contrast and used to evaluate the relative effectiveness of TM and MSS bands in detecting submerged vegetation.

Klemas, V.↗
NASA NTRS1983

Contribution of LANDSAT-4 thematic mapper data to geologic exploration

The increased number of carefully selected narrow spectral bands and the increased spatial resolution of thematic mapper data over previously available satellite data contribute greatly to geologic exploration, both by providing spectral information that permits lithologic differentiation and recognition of alteration and spatial information that reveals structure. As vegetation and soil cover increase, the value of spectral components of TM data decreases relative to the value of the spatial component of the data. However, even in vegetated areas, the greater spectral breadth and discrimination of TM data permits improved recognition and mapping of spatial elements of the terrain. As our understanding of the spectral manifestations of the responses of soils and vegetation to unusual chemical environments increases, the value of spectral components of TM data to exploration will greatly improve in covered areas.

Everett, J. R.↗
NASA NTRS1983

LANDSAT 4 image data quality analysis

A comparative analysis of TM and MSS data was completed and the results indicate that there are half as many separable spectral classes in the MSS data than in TM. In addition, the minimum separability between classes was also much less in MSS data. Radiometric data quality was also investigated for the TM by computing power spectrum estimates for dark-level data from Lake Michigan. Two significant coherent noise frequencies were observed, one with a wavelength of 3.12 pixels and the other with a 17 pixel wavelength. The amplitude was small (nominally .6 digital count standard deviation) and the noise appears primarily in Bands 3 and 4. No significant levels were observed in other bands. Scan angle dependent brightness effects were also evaluated.

Anuta, P. E.↗
NASA NTRS1983

The use of linear feature detection to investigate thematic mapper data performance and processing

The geometric and radiometric characteristics of thematic mapper data through analysis of linear features in the data are investigated. The particular aspects considered are: (1) thematic mapper ground IFOV; (2) radiometric contrast between linear features and background; (3) precision of system geometric correction; (4) band-to-band registration; and (5) potential utility of TM data for linear feature detection especially as compared to MSS data. It is shown that TM data may be used to estimate TM pixel size and to illustrate band-band mis-registration. Further, the geometry and radiometry of the data are sufficiently precise to allow accurate estimation of the widths of linear features. In optimum conditions features one quarter of a pixel in width may be accurately measured. These results have considerable potential for applications for hydrological and topographic mapping.

Gurney, C. M.↗
NASA NTRS1983

An analysis of new techniqes for radiometric correction of LANDSAT-4 Thematic Mapper images

The utility of methods for generating TM RLUTS which can improve the quality of the resultant images was investigated. The TM-CCT-ADDS tape was changed to account for a different collection window for the calibration data. Several scenes of Terrebonne Bay, Louisiana and the Grand Bahamas were analyzed to evaluate the radiometric corrections operationally applied to the image data and to investigate several techniques for reducing striping in the images. Printer plots for the TM shutter data were produced and detector statistics were compiled and plotted. These statistics included various combinations of the average shutter counts for each scan before and after DC restore for forward and reverse scans. Results show that striping is caused by the detectors becoming saturated when they view a bright cloud and depress the DC restore level.

Kogut, J.↗
NASA NTRS1984

In-flight Absolute Radiometric Calibration of the Thematic Mapper

Ground spectral reflectance and atmospheric spectral optical depth measurements made at White Sands, New Mexico were used with an atmospheric radiative transfer program to determine the spectral radiance at the entrance pupil of the LANDSAT-4 TM. Comparison with the output digital counts of the TM, when imaging the measured ground area, provided an absolute calibration for five detectors in TM bands 2, 3, and 4. By reference to an adjacent, larger uniform area, the calibration was extended to all 16 detectors in each of three bands. Preflight calibration results agreed with these inflight measurements to 6.6%, 2.4%, and 12.9% in bands 2,3, and 4, respectively.

Palmer, J.↗
NASA NTRS1984

Study on spectral/radiometric characteristics of the Thematic Mapper for land use applications

An information theoretic measure of multispectral information content is developed and applied to a simultaneous LANDSAT TM and MSS data set. The entropy based function measures the dispersion and concentration of signal values in various data spaces, irrespective of specific class memberships. It is used to compare the information content of TM and MSS and of various subsets of TM and MSS bans, as well as tasseled cap transformations of the band values. Differences exist between the information measure results and results using variance based measures. System design information capacities and data space volumes are also compared. The results and observations presented are considered preliminary in nature since only one real and one simulated data set are analyzed.

Malila, W. A.↗
NASA NTRS1984

LANDSAT 4 investigations of Thematic Mapper and Multispectral Scanner applications

Interband detector noise was suppressed in the TIPS TM North Dakota data by median filtering. Procedures were developed to optimize the visual information content of thematic mapper data and evaluate the resulting photographic products by visual interpretation. A digital to analog TM transfer function was developed which properly placed the digital values on the most useable portion of film response curve. Utilizing the calculated minimum, mean, and maximum and the respective standard deviations of the bands from 50 sample scenes of TM data, look up tables were designed which resulted in acceptable photographic products. These products were evaluated by generation of color composites of selected band combinations using standard photo production procedures, and visual interpretation of scene features.

Lauer, D. T.↗