Elijah Ramsey, III, Ph.D. (Former Employee)
Science and Products
Filter Total Items: 76
Monitoring the recovery of Juncus roemerianus marsh burns with the normalized difference vegetation index and Landsat Thematic Mapper data
Nine atmospherically corrected Landsat Thematic Mapper images were used to generate mean normalized difference vegetation indices (NDVI) at 11 burn sites throughout a coastal Juncus roemerianus marsh in St. Marks National Wildlife Refuge, Florida. Time-since-burn, the time lapse from the date of burn to the date of image collection, was related to variation in mean NDVI over time. Regression analy
Authors
Elijah W. Ramsey, S.K. Sapkota, F.G. Barnes, G.A. Nelson
Forest impact estimated with NOAA AVHRR and landsat TM data related to an empirical hurricane wind-field distribution
An empirical model was used to relate forest type and hurricane-impact distribution with wind speed and duration to explain the variation of hurricane damage among forest types along the Atchafalaya River basin of coastal Louisiana. Forest-type distribution was derived from Landsat Thematic Mapper image data, hurricane-impact distribution from a suite of transformed advanced very high resolution r
Authors
Elijah W. Ramsey, M.E. Hodgson, S.K. Sapkota, G.A. Nelson
Coastal change analysis program implemented in Louisiana
Landsat Thematic Mapper images from 1990 to 1996 and collateral data sources were used to classify the land cover of the Mermentau River Basin (MRB) within the Chenier Plain of coastal Louisiana. Landcover classes followed the definition of the National Oceanic and Atmospheric Administration's Coastal Change Analysis Program; however, classification methods had to be developed as part of this stud
Authors
Elijah W. Ramsey, G.A. Nelson, S.K. Sapkota
Landcover classification of Padre Island National Seashore
No abstract available.
Authors
Elijah W. Ramsey, G.A. Nelson, S.K. Sapkota, W. Phillips, S. Laine
Landcover Classification of Lake Meredith National Recreation Area
No abstract available.
Authors
Elijah W. Ramsey, G.A. Nelson, S.K. Sapkota, M. Strong
Conveying multiple, complex themes and classes for natural resource assessments
Two methods were used to convey the spatial association between a classified forested landscape, the distribution of a hurricane impact, and the subsequent recovery of the habitat from the storm. The first method used a constant hue matrix with varying intensity to visually represent combinations of impact and recovery magnitudes. The second combined two colors of constant hue to represent the imp
Authors
Elijah Ramsey III, Marshall L. Strong
Using multiple-polarization L-band radar to monitor marsh burn recovery
Aircraft L-band VV-, HH-, and VH-polarizations were examined as tools for monitoring burn recovery in a coastal marsh. Significant relationships were observed between time-since-burn (difference between burn and image collection dates; 550-900 days after burn) and returns related to all polarizations. As marsh burn recovery progressed, VV returns decreased while HH and VH returns increased. Radar
Authors
Elijah W. Ramsey, G.A. Nelson, S.K. Sapkota, S.C. Laine, J. Verdi, S. Rrasznay
Resource management of forested wetlands: Hurricane impact and recovery mapped by combining Landsat TM and NOAA AVHRR data
A temporal suite of NOAA Advanced Very High Resolution Radiometer (AVHRR) images, transformed into a vegetation biomass indicator, was combined with a single-date classification of Landsat Thematic Mapper (TM) to map the association between forest type and hurricane effects. Hurricane effects to the forested wetland included an abrupt decrease and subsequent increase in biomass. The decrease was a
Authors
Elijah Ramsey III, D.K. Chappell, Dennis M. Jacobs, Sijan Sapkota, D.G. Baldwin
Generation of coastal marsh topography with radar and ground-based measurements
A topographic surface of a low lying coastal marsh was created by using three flood extent vectors digitized from ERS-1 SAR images and two elevation contours from U.S. Geological Survey topographic quadrangles. Point measurement of water depth at the times of the SAR collections allowed conversion of the radar measured flood extent vectors to topographic contours. Generation of the topographic sur
Authors
Elijah W. Ramsey, G.A. Nelson, S.C. Laine, R.G. Kirkman, W. Topham
Classifying coastal resources by integrating optical and radar imagery and color infrared photography
A progressive classification of a marsh and forest system using Landsat Thematic Mapper (TM), color infrared (CIR) photograph, and ERS-1 synthetic aperture radar (SAR) data improved classification accuracy when compared to classification using solely TM reflective band data. The classification resulted in a detailed identification of differences within a nearly monotypic black needlerush marsh. Ac
Authors
Elijah W. Ramsey, Gene A. Nelson, Sijan Sapkota
Comparison of Landsat Thematic Mapper and high resolution photography to Identify change in complex coastal wetlands
Landsat Thematic Mapper (TM) images were used to generate pre- and post- hurricane classifications of a complex wetland environment in southern Louisiana. Accuracies were estimated as 77% and 81.5% for the pre- and post- classifications that included water, emergent vegetation, floating vegetation, and mud flats. From the two classifications, areas of emergent vegetation loss were identified. The
Authors
Elijah Ramsey III, S.C. Laine
Science and Products
Filter Total Items: 76
Monitoring the recovery of Juncus roemerianus marsh burns with the normalized difference vegetation index and Landsat Thematic Mapper data
Nine atmospherically corrected Landsat Thematic Mapper images were used to generate mean normalized difference vegetation indices (NDVI) at 11 burn sites throughout a coastal Juncus roemerianus marsh in St. Marks National Wildlife Refuge, Florida. Time-since-burn, the time lapse from the date of burn to the date of image collection, was related to variation in mean NDVI over time. Regression analy
Authors
Elijah W. Ramsey, S.K. Sapkota, F.G. Barnes, G.A. Nelson
Forest impact estimated with NOAA AVHRR and landsat TM data related to an empirical hurricane wind-field distribution
An empirical model was used to relate forest type and hurricane-impact distribution with wind speed and duration to explain the variation of hurricane damage among forest types along the Atchafalaya River basin of coastal Louisiana. Forest-type distribution was derived from Landsat Thematic Mapper image data, hurricane-impact distribution from a suite of transformed advanced very high resolution r
Authors
Elijah W. Ramsey, M.E. Hodgson, S.K. Sapkota, G.A. Nelson
Coastal change analysis program implemented in Louisiana
Landsat Thematic Mapper images from 1990 to 1996 and collateral data sources were used to classify the land cover of the Mermentau River Basin (MRB) within the Chenier Plain of coastal Louisiana. Landcover classes followed the definition of the National Oceanic and Atmospheric Administration's Coastal Change Analysis Program; however, classification methods had to be developed as part of this stud
Authors
Elijah W. Ramsey, G.A. Nelson, S.K. Sapkota
Landcover classification of Padre Island National Seashore
No abstract available.
Authors
Elijah W. Ramsey, G.A. Nelson, S.K. Sapkota, W. Phillips, S. Laine
Landcover Classification of Lake Meredith National Recreation Area
No abstract available.
Authors
Elijah W. Ramsey, G.A. Nelson, S.K. Sapkota, M. Strong
Conveying multiple, complex themes and classes for natural resource assessments
Two methods were used to convey the spatial association between a classified forested landscape, the distribution of a hurricane impact, and the subsequent recovery of the habitat from the storm. The first method used a constant hue matrix with varying intensity to visually represent combinations of impact and recovery magnitudes. The second combined two colors of constant hue to represent the imp
Authors
Elijah Ramsey III, Marshall L. Strong
Using multiple-polarization L-band radar to monitor marsh burn recovery
Aircraft L-band VV-, HH-, and VH-polarizations were examined as tools for monitoring burn recovery in a coastal marsh. Significant relationships were observed between time-since-burn (difference between burn and image collection dates; 550-900 days after burn) and returns related to all polarizations. As marsh burn recovery progressed, VV returns decreased while HH and VH returns increased. Radar
Authors
Elijah W. Ramsey, G.A. Nelson, S.K. Sapkota, S.C. Laine, J. Verdi, S. Rrasznay
Resource management of forested wetlands: Hurricane impact and recovery mapped by combining Landsat TM and NOAA AVHRR data
A temporal suite of NOAA Advanced Very High Resolution Radiometer (AVHRR) images, transformed into a vegetation biomass indicator, was combined with a single-date classification of Landsat Thematic Mapper (TM) to map the association between forest type and hurricane effects. Hurricane effects to the forested wetland included an abrupt decrease and subsequent increase in biomass. The decrease was a
Authors
Elijah Ramsey III, D.K. Chappell, Dennis M. Jacobs, Sijan Sapkota, D.G. Baldwin
Generation of coastal marsh topography with radar and ground-based measurements
A topographic surface of a low lying coastal marsh was created by using three flood extent vectors digitized from ERS-1 SAR images and two elevation contours from U.S. Geological Survey topographic quadrangles. Point measurement of water depth at the times of the SAR collections allowed conversion of the radar measured flood extent vectors to topographic contours. Generation of the topographic sur
Authors
Elijah W. Ramsey, G.A. Nelson, S.C. Laine, R.G. Kirkman, W. Topham
Classifying coastal resources by integrating optical and radar imagery and color infrared photography
A progressive classification of a marsh and forest system using Landsat Thematic Mapper (TM), color infrared (CIR) photograph, and ERS-1 synthetic aperture radar (SAR) data improved classification accuracy when compared to classification using solely TM reflective band data. The classification resulted in a detailed identification of differences within a nearly monotypic black needlerush marsh. Ac
Authors
Elijah W. Ramsey, Gene A. Nelson, Sijan Sapkota
Comparison of Landsat Thematic Mapper and high resolution photography to Identify change in complex coastal wetlands
Landsat Thematic Mapper (TM) images were used to generate pre- and post- hurricane classifications of a complex wetland environment in southern Louisiana. Accuracies were estimated as 77% and 81.5% for the pre- and post- classifications that included water, emergent vegetation, floating vegetation, and mud flats. From the two classifications, areas of emergent vegetation loss were identified. The
Authors
Elijah Ramsey III, S.C. Laine