34,671 research outputs found

    LANDSAT-4/5 image data quality analysis

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    A LANDSAT Thematic Mapper (TM) quality evaluation study was conducted to identify geometric and radiometric sensor errors in the post-launch environment. The study began with the launch of LANDSAT-4. Several error conditions were found, including band-to-band misregistration and detector-to detector radiometric calibration errors. Similar analysis was made for the LANDSAT-5 Thematic Mapper and compared with results for LANDSAT-4. Remaining band-to-band misregistration was found to be within tolerances and detector-to-detector calibration errors were not severe. More coherent noise signals were observed in TM-5 than in TM-4, although the amplitude was generally less. The scan direction differences observed in TM-4 were still evident in TM-5. The largest effect was in Band 4 where nearly a one digital count difference was observed. Resolution estimation was carried out using roads in TM-5 for the primary focal plane bands rather than field edges as in TM-4. Estimates using roads gave better resolution. Thermal IR band calibration studies were conducted and new nonlinear calibration procedures were defined for TM-5. The overall conclusion is that there are no first order errors in TM-5 and any remaining problems are second or third order

    Landsat 4 Thematic Mapper Calibration Update

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    The Landsat-4 Thematic Mapper collected imagery of the Earth's surface from 1982 to 1993. Although largely overshadowed by Landsat 5, which was launched in 1984, Landsat 4 TM imagery extends the Thematic Mapper-based record of the Earth back to 1982 and also substantially supplements the image archive collected by Landsat 5. To provide a consistent calibration record for the TM instruments, Landsat 4 TM was cross-calibrated to Landsat 5 using nearly simultaneous overpass imagery of pseudo-invariant calibration sites (PICS) in the time period of 1988 through 1990. To determine if the radiometric gain of Landsat 4 had changed over its lifetime, time series from two PICS locations, a Saharan site known as Libya 4 and a site in southwest North America, commonly referred to as the Sonoran Desert PICS, were developed. Results indicated that Landsat 4 had been very stable over its lifetime with no discernible degradation in sensor performance in all the reflective bands except band 1. In contrast, band 1 exhibited a 12% decay in responsivity over the lifetime of the instrument. Results from this work have been implemented at USGS EROS, which enables users of Landsat TM data sets to obtain consistently calibrated data from Landsat 4 and 5 TM as well as Landsat 7 ETM+ instruments

    LANDSAT TM image data quality analysis for energy-related applications

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    This project represents a no-cost agreement between National Aeronautic Space Administration Goddard Space Flight Center (NASA GSFC) and the Pacific Northwest Laboratory (PNL). PNL is a Department of Energy (DOE) national laboratory operted by Battelle Memorial Institute at its Pacific Northwest Laboratories in Richland, Washington. The objective of this investigation is to evaluate LANDSAT's thematic mapper (TM) data quality and utility characteristics from an energy research and technological perspective. Of main interest is the extent to which repetitive TM data might support DOE efforts relating to siting, developing, and monitoring energy-related facilities, and to basic geoscientific research. The investigation utilizes existing staff and facility capabilities, and ongoing programmatic activities at PNL and other DOE national laboratories to cooperatively assess the potential usefulness of the improved experimental TM data. The investigation involves: (1) both LANDSAT 4 and 5 TM data, (2) qualitative and quantitative use consideration, and 3) NASA P (corrected) and A (uncorrected) CCT analysis for a variety of sites of DOE interest. Initial results were presented at the LANDSAT Investigator's Workshops and at specialized LANDSAT TM sessions at various conferences

    Relative radiometric calibration of LANDSAT TM reflective bands

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    Raw thematic mapper (TM) calibration data from pre-launch tests and in-orbit acquisitions from LANDSAT 4 and 5 satellites are analyzed to assess the radiometric characteristics of the TM sensor. A software program called TM radiometric and algorithmic performance program (TRAPP) was used for the majority of analyses. Radiometric uncertainty in the final TM image originates from: (1) scene variability (solar irradiance and atmospheric scattering); (2) optical and electrical variability of the sensor; and (3) variability introduced during image processing

    The INPE handouts to the 6th LANDSAT Technical Working Group (LTWG) Meeting

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    LANDSAT receiving and processing system in its present configuration and status are described, as well as the experience already obtained with LANDSATs 4 and 5. The revised table of station plans for TM reception and products and of implementation schedule for data formats employing superstructure conventions is updated. Standardization of the worldwide reference systems is proposed. The INPE preliminary TM products price list is included. A TM image received and processed is shown to illustrate the appearance of the products offered

    Aplikasi Penginderaan Jauh Untuk Identifikasi Sebaran Batubara Permukaan Di Kabupaten Muara Enim, Sumatera Selatan

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    Indonesia merupakan negara kepulauan yang banyak menyimpan sumber daya alam khususnya batubara. Melihat prospek kedepannya, banyak Perusahaan-Perusahaan yang bergerak di bidang eksplorasi dan eksploitasi batubara. Seiring berkembangnya teknologi penginderaan jauh, maka diharapkan data penginderaan jauh Landsat 5 TM dapat dimanfaatkan sebagai sarana yang murah, efektif untuk pengenalan dan mengetahui sebaran batubara. Citra penginderaan jauh Landsat 5 TM pada penelitian ini diharapkan mampu mendeteksi adanya struktur geologi di lokasi penelitian. Kegiatan penambangan batubara sangat dipengaruhi oleh faktor topografi dan geologi. Faktor-faktor tersebut dapat dikenali melalui pengamatan lapangan, data penginderaan jauh, peta topografi, dan peta geologi.Berdasarkan hasil interpretasi pada citra Landsat 5 TM, didapatkan hasil yaitu peta pola aliran, peta bentuklahan, peta struktur geologi, peta penggunaan lahan, dari keempat peta tersebut dibuat peta satuan lahan yang digunakan untuk mengecek hasil interpretasi dengan Kenyataan yang ada dilapangan. Penginderaan jauh dimungkinkan memperoleh data lebih cepat dan lebih murah dibandingkan pengukuran langsung dilapangan

    Prelaunch absolute radiometric calibration of LANDSAT-4 protoflight Thematic Mapper

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    Results are summarized and analyzed from several prelaunch tests with a 122 cm integrating sphere used as part of the absolute radiometric calibration experiments for the protoflight TM sensor carried on the LANDSAT-4 satellite. The calibration procedure is presented and the radiometric sensitivity of the TM is assessed. The internal calibrator and dynamic range after calibration are considered. Tables show dynamic range after ground processing, spectral radiance to digital number and digital number to spectral radiance values for TM bands 1, 2, 3, 4, 5, 7 and for channel 4 of band 6

    Análisis de Mezclas Espectrales para el estudio de la deforestación y establecimiento de la línea de referencia de emisiones en el marco del programa REDD. Aplicación a la región de San Martín, Perú.

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    La determinación de la línea histórica de deforestación como parte del establecimiento de la línea de referencia de emisiones, en el marco del programa REDD (Reducing Emissions from Deforestation and Forest Degradation), permite medir la evolución de la pérdida de bosque en un periodo definido de tiempo. El objetivo fue calcular la línea histórica de deforestación mediante estudio multitemporal para el periodo 1998-2011, en la región de San Martín (Perú), utilizando la metodología de Análisis de Mezclas Espectrales (Spectral Mixtures Analysis) con imágenes Landsat 5-TM. Palabras clave: teledetección, Landsat 5-TM, análisis de mezclas espectrales, REDD, Protocolo de Kioto, deforestación, Amazonía, SMA Spectral Mixture Analysis for the study of deforestation and establishing reference emissions level within the REDD Program framework. Application to the region of San Martin, Peru. Abstract: Determination of the historical baseline of deforestation as part of establishing the reference emissions level within the REDD (Reducing Emissions from Deforestation and Forest Degradation) Program framework allows for the measurement of the evolution of forest loss over a defined period time. The objective was to estimate the historical baseline of deforestation through a multi-temporal study for the period 1998-2011, in the region of San Martin (Peru), using the methodology of Spectral Mixture Analysis (Mixtures Spectral Analysis) from Landsat 5-TM imagery. Keywords: remote sensing, Landsat 5-TM, spectral mixtures analysis, REDD, Kyoto Protocol, deforestation, Amazon, SM

    Forty-Year Calibrated Record of Earth-Surface Reflected Radiance from Landsat: A Review

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    Sensors on Landsat satellites have been collecting images of the Earth's surface for nearly 40 years. These images have been invaluable for characterizing and detecting changes in the land cover and land use of the world. Although initially conceived as primarily picture generating sensors, even the early sensors were radiometrically calibrated and spectrally characterized prior to launch and incorporated some capabilities to monitor their radiometric calibration once on orbit. Recently, as the focus of studies has shifted to monitoring Earth surface parameters over significant periods of time, serious attention has been focused toward bringing the data from all these sensors onto a common radiometric scale over this 40-year period. This effort started with the most recent systems and then was extended back in time. Landsat-7 ETM+, the best-characterized sensor of the series prior to launch and once on orbit, and the most stable system to date, was chosen to serve as the reference. The Landsat-7 project was the first of the series to build an image assessment system into its ground system, allowing systematic characterization of its sensors and data. Second, the Landsat-5 TM (still operating at the time of the Landsat-7 launch and continues to operate) calibration history was reconstructed based on its internal calibrator, vicarious calibrations, pseudo-invariant sites and a tie to Landsat-7 ETM+ at the time of the commissioning of Landsat-7. This process was performed in two iterations: the earlier one relied primarily on the TM internal calibrator. When this was found to have some deficiencies, a revised calibration was based more on pseudo-invariant sites, though the internal calibrator was still used to establish the short-term variations in response due to icing build up on the cold focal plane. As time progressed, a capability to monitor the Landsat-5 TM was added to the image assessment system. The Landsat-4 TM, which operated from 1982-1992, was the third system to which the radiometric scale was extended. The limited and broken use of the Landsat-4 TM made this analysis more difficult. Eight-day separated image pairs from Landsat-5 combined with analysis of pseudo invariant sites established this history. The fourth and most challenging effort was making the Landsat-1 to -5 MSS sensors' data internally radiometrically consistent. This effort was particularly complicated by the age of the MSS data, varying formats and processing levels in the archive, limited datasets, and limited documentation available. Ultimately, pseudo-invariant sites were identified in North America and used for this effort. Note that most of the Landsat-MSS archived data had already been calibrated using the MSS internal calibrators, so this processing was imbedded in the result. The final effort was developing an absolute scale for Landsat MSS similar to what was already established for the "TM" sensors. This was accomplished by using simultaneous data from Landsat-5 MSS and Landsat-5 TM, accounting for spectral differences between the sensors using EO-1 Hyperion data. The recalibrated history of the Landsat data and implications to users are discussed. The key result from this work is a consistently calibrated Landsat data archive that spans nearly 40 years with total uncertainties on the order of 10% or less for most sensors and bands

    Historic thermal calibration of Landsat 4 TM through an improved physics based approach

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    This work is intended to establish the calibration of the Thematic Mapper (TM) sensor, thermal band (band 6) aboard the Landsat 4 Spacecraft. Due to multiple organizations having operational control of the spacecraft and a lack of historical calibration data, a physics based approach will be used to calibrate the thermal data recorded over water during the operational lifetime of the spacecraft, which spanned 1983-1993. Using historical data from weather station observations, Radiosonde instruments, and moored weather buoys owned and operated by the National Data Buoy Center (NDBC), a ground truth comparison can be calculated and propagated through the atmosphere using a physics based model. The ground truth measurements are then compared to archived Landsat 4 data to determine how well the instrument is calibrated. This comparison over many data points allows construction of an overall calibration curve for the Landsat 4 data over the lifetime of the spacecraft. In addition to calibrating the Landsat 4 TM, this research will also include investigation into a possible transition period of negative to positive bias on the Landsat 5 TM, somewhere in the 1996-1999 timeframe. The same technique will be used in both calibration attempts. Results indicate that the Landsat 4 data was well calibrated in the timeframe before storage (1983-1984), however after the storage period (1987-1993) the sensor had a negative bias of -3.3 K. It is suggested to bias post 1987 Landsat 4 data by adding 0.4533 [W/m2 sr μm] to the sensor reaching radiance. Results from this correction radiometrically correct Landsat 4 data to ±0.48 K verified through an error analysis of the calibration procedure. The results from this study are consistent with the results from previous work performed on Landsat 5 TM in 2008. Results from the Landsat 5 study were inconclusive in finding a precise date for the bias shift in the 1996-1999 timeframe of Landsat 5 data. Twenty one additional data points were added to previous work completed in 2008, but no obvious shift was observed. This procedure for calibrating the Landsat 4 TM sensor tested the limits of the physics based calibration approach and proved that multiple buoys, multiple locations of the buoys (different bodies of water), unfavorable wind conditions, and Radiosonde data from larger distances away from the target can still produce valid results when calibrating a thermal sensor. Testing the robustness of the physics based calibration process opens the door to more available data, resulting in more extensive calibration curves for past work and future systems
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