Darrel Williams, PhD, retired from federal government service in January 2010 after 35 years of Earth science-focused research and management activities at NASA’s Goddard Space Flight Center. Upon retirement from NASA, he accepted the Chief Scientist position at Global Science
... Daily global cloud forecast maps were driven from NOAA's Suitland Maryland facil... more ... Daily global cloud forecast maps were driven from NOAA's Suitland Maryland facility to NASA/GSFC ... Japan China/Brz China/Brz China/Brz Multiple4 France France France Launch year 2006 2003 ... IRMSS3 WFI3 SLIM6 HRV (2) HRVIR (2) HRG (2) Bands: 1 Blue 10 20 Green 10 ...
Ieee Transactions on Geoscience and Remote Sensing, Nov 1, 1987
The fluorescence spectra and fluorescence induction kinetics of plants excited with a pulsed nitr... more The fluorescence spectra and fluorescence induction kinetics of plants excited with a pulsed nitrogen laser beam emitting at 337 nm were found to be correlated with plant type, as well as with changes in the physiology of the plant as the result of various kinds of environmental stress. The plant types that were studied included herbaceous dicots, monocots, hardwoods, conifers,
One of the major catalysts leading to the development of the global-scale Earth Systems Science c... more One of the major catalysts leading to the development of the global-scale Earth Systems Science concept, the International Geosphere-Biosphere Program, and the U.S. Global Change Research Program were the unique views of Earth provided by Landsat sensors over the past 25 years. This paper ad- dresses Landsat's contributions in the Earth Systems Science arena. Early successes in observing the Earth's
The Landsat Earth observation approach introduced in 1972 created a new way of monitoring land co... more The Landsat Earth observation approach introduced in 1972 created a new way of monitoring land cover and land use globally. The Landsat 7 mission, successfully launched on April 15, 1999, continues those observations and demonstrates significant progress in precise numerical radiometry, spectral differentiation, and seasonally repetitive monitoring. Substantial improvements in calibration procedures, both prior to launch and during normal operations, have also been made to ensure long-term stability in the acquired spectral radiometry. Landsat 7 data acquisitions are being driven by a long-term data acquisition plan that was designed to ensure that substantially cloud-free, seasonal coverage would be recorded and archived in the US for all land areas of the globe. NASA competitively selected a Landsat Science Team, consisting of representatives from US universities and government agencies, to exploit the Landsat 7 record for global change research. This team is addressing the technical and analytical means to process and analyze the core of this observation record, and for the first time in the history of the Landsat mission, the technical and operational aspects of the mission are being driven by the goals of the US science community. The expected outcome of these efforts is a rapid improvement in understanding the Earth system, as well as conceptual knowledge that will underpin significant advancements in the application of this technology for commercial, operational, educational, and research purposes. Pathways to achieve effective Landsat continuity in the early decades of the 21st century are also being given careful attention, and there is no question that the lessons learned from the Landsat 7 mission will strongly influence these next-generation sensor systems. D
Landsat-7 mission and early results. [Proceedings of SPIE 3870, 299 (1999)]. John L. Barker, S. K... more Landsat-7 mission and early results. [Proceedings of SPIE 3870, 299 (1999)]. John L. Barker, S. Kenneth Dolan, Phillip A. Sabelhaus, Darrel L. Williams, James R. Irons, Brian L. Markham, Joseph T. Bolek, Steven S. Scott, RJ ...
The technical innovations of precise numerical radiometry, spectral differentiation and seasonall... more The technical innovations of precise numerical radiometry, spectral differentiation and seasonally repetitive monitoring, introduced by the Landsat system, have created a new measurement approach to terrestrial monitoring. The Landsat-7 mission reflects significant progress in realizing the scientific potential of this measurement strategy. Substantial improvements in calibration procedures, both prior to launch and normal operations, have been accomplished to insure long-term stability in the acquired spectral radiometry. For the first time, Landsat-7 will be operated with a long-term acquisition plan that insures, barring national emergencies, that substantially cloud-free, seasonal coverage will be recorded (in the US archives) for all land areas of the globe. In addition, NASA competitively selected a Landsat Science Team, made of representatives from US universities and government agencies to exploit the Landsat-7 record for global change research. This team is addressing the t...
... Daily global cloud forecast maps were driven from NOAA's Suitland Maryland facil... more ... Daily global cloud forecast maps were driven from NOAA's Suitland Maryland facility to NASA/GSFC ... Japan China/Brz China/Brz China/Brz Multiple4 France France France Launch year 2006 2003 ... IRMSS3 WFI3 SLIM6 HRV (2) HRVIR (2) HRG (2) Bands: 1 Blue 10 20 Green 10 ...
Ieee Transactions on Geoscience and Remote Sensing, Nov 1, 1987
The fluorescence spectra and fluorescence induction kinetics of plants excited with a pulsed nitr... more The fluorescence spectra and fluorescence induction kinetics of plants excited with a pulsed nitrogen laser beam emitting at 337 nm were found to be correlated with plant type, as well as with changes in the physiology of the plant as the result of various kinds of environmental stress. The plant types that were studied included herbaceous dicots, monocots, hardwoods, conifers,
One of the major catalysts leading to the development of the global-scale Earth Systems Science c... more One of the major catalysts leading to the development of the global-scale Earth Systems Science concept, the International Geosphere-Biosphere Program, and the U.S. Global Change Research Program were the unique views of Earth provided by Landsat sensors over the past 25 years. This paper ad- dresses Landsat's contributions in the Earth Systems Science arena. Early successes in observing the Earth's
The Landsat Earth observation approach introduced in 1972 created a new way of monitoring land co... more The Landsat Earth observation approach introduced in 1972 created a new way of monitoring land cover and land use globally. The Landsat 7 mission, successfully launched on April 15, 1999, continues those observations and demonstrates significant progress in precise numerical radiometry, spectral differentiation, and seasonally repetitive monitoring. Substantial improvements in calibration procedures, both prior to launch and during normal operations, have also been made to ensure long-term stability in the acquired spectral radiometry. Landsat 7 data acquisitions are being driven by a long-term data acquisition plan that was designed to ensure that substantially cloud-free, seasonal coverage would be recorded and archived in the US for all land areas of the globe. NASA competitively selected a Landsat Science Team, consisting of representatives from US universities and government agencies, to exploit the Landsat 7 record for global change research. This team is addressing the technical and analytical means to process and analyze the core of this observation record, and for the first time in the history of the Landsat mission, the technical and operational aspects of the mission are being driven by the goals of the US science community. The expected outcome of these efforts is a rapid improvement in understanding the Earth system, as well as conceptual knowledge that will underpin significant advancements in the application of this technology for commercial, operational, educational, and research purposes. Pathways to achieve effective Landsat continuity in the early decades of the 21st century are also being given careful attention, and there is no question that the lessons learned from the Landsat 7 mission will strongly influence these next-generation sensor systems. D
Landsat-7 mission and early results. [Proceedings of SPIE 3870, 299 (1999)]. John L. Barker, S. K... more Landsat-7 mission and early results. [Proceedings of SPIE 3870, 299 (1999)]. John L. Barker, S. Kenneth Dolan, Phillip A. Sabelhaus, Darrel L. Williams, James R. Irons, Brian L. Markham, Joseph T. Bolek, Steven S. Scott, RJ ...
The technical innovations of precise numerical radiometry, spectral differentiation and seasonall... more The technical innovations of precise numerical radiometry, spectral differentiation and seasonally repetitive monitoring, introduced by the Landsat system, have created a new measurement approach to terrestrial monitoring. The Landsat-7 mission reflects significant progress in realizing the scientific potential of this measurement strategy. Substantial improvements in calibration procedures, both prior to launch and normal operations, have been accomplished to insure long-term stability in the acquired spectral radiometry. For the first time, Landsat-7 will be operated with a long-term acquisition plan that insures, barring national emergencies, that substantially cloud-free, seasonal coverage will be recorded (in the US archives) for all land areas of the globe. In addition, NASA competitively selected a Landsat Science Team, made of representatives from US universities and government agencies to exploit the Landsat-7 record for global change research. This team is addressing the t...
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