T. Schmugge - Academia.edu (original) (raw)
Papers by T. Schmugge
IGARSS '98. Sensing and Managing the Environment. 1998 IEEE International Geoscience and Remote Sensing. Symposium Proceedings. (Cat. No.98CH36174), 1998
The JORNada EXperiment (JORNEX) held at the Jornada Experimental Range in southern New Mexico aim... more The JORNada EXperiment (JORNEX) held at the Jornada Experimental Range in southern New Mexico aims at the description of the surface energy balance of a desert grassland ecosystem. A large array of both field and remote sensing data have been collected from 1995 to 1998. Remote sensing data collected consists of visible and thermal infrared imagery, video imagery and laser profiler data. These data are being used to infer land surface characteristics such as surface temperature, albedo and roughness. These land surface characteristics can be used as input for surface energy balance models coupled with atmospheric models. However atmospheric models work with very coarse grid cells of at least 50*50 km. Remote sensing data typically has a geometrical resolution much smaller than 50*50 km. In addition to the scale discrepancy, surface energy balance models are generally nonlinear algorithms, which amplifies scale problems. High resolution input data will not necessarily give the same results as low resolution input data. The problem arises of how to scale up the calculated surface energy balance fluxes to the much coarser resolution of the atmospheric model. The first step is to derive the length scales of the land surface characteristics involved in the calculation of the surface energy balance, therefore determining the maximum resolution required to sample the area. High resolution (~4m) NIR and TIR images with variogram and wavelet techniques will be used to study scaling
This study assesses the effects of physical structure and composition of shrub-coppice dune lands... more This study assesses the effects of physical structure and composition of shrub-coppice dune landscapes on anisotropy in the NASA MODIS-ASTER Airborne Simulator (MASTER) solar channels, and investigates the viability of simulating multi-angular data sets using off-nadir airborne imaging radiometry from a single overpass by means of data segmentation. Segmentation data are plant density and cover and spectral measures derived from high-resolution aerial photography and classified Landsat 7 Enhanced Thematic Mapper imagery. The directional signal contributes a variation of 5-10% in reflectance, necessitating angular corrections. For most areas the signal appears to differ only slightly with changes in landscape structure and composition because the view/illumination geometry is poor and reflectance is dominated by bright soils. Further work is required to determine whether simple models would be adequate for angular corrections.
The knowledge of surface fluxes is of prime interest in agronomy, meteorology and hydrology. Seve... more The knowledge of surface fluxes is of prime interest in agronomy, meteorology and hydrology. Several models were developed recently to estimate surface fluxes using remote sensing data. A possible way to distinguish these models is the decoupling or not of soil and vegetation components, which lead to label ``one layer'' or ``two layers'' models. Considering separate soil and vegetation components
The land surface emissivity is often overlooked when considering surface properties that effect t... more The land surface emissivity is often overlooked when considering surface properties that effect the energy balance. However, knowledge of the emissivity in the window region is important for determining the longwave radiation balance and its subsequent effect on surface temperature. The net longwave radiation (NLR) is strongly affected by the difference between the temperature of the emitting surface and the sky brightness temperature, this difference will be the greatest in the window region. Outside the window region any changes in the emitted radiation by emissivity variability are mostly compensated for by changes in the reflected sky brightness. The emissivity variability is typically greatest in arid regions where the exposed soil and rock surfaces display the widest range of emissivity. For example, the dune regions of North Africa have emissivities of 0.7 or less in the 8 to 9 micrometer wavelength band due to the quartz sands of the region, which can produce changes in NLR ...
Since the launch of NASA's Terra satellite in December 1999, the Advanced Spaceborne Thermal ... more Since the launch of NASA's Terra satellite in December 1999, the Advanced Spaceborne Thermal Emission and Reflection (ASTER) instrument has made a number of observations of the Elephant Butte Reservoir. The first observations were in June 2000 and the most recent were in October 2007. This period includes the recent drought conditions and the earlier full water conditions. The area of the reservoir was estimated for each of these scenes and compared with known water levels. The ASTER observations include both the visible reflectance and the thermal infrared emission (surface temperature). Both spectral regions can provide good contrast between the water and the surrounding land. This contrast makes the area estimation straightforward.
The application of an electronically steered thinned array L-band radiometer (ESTAR) for soil moi... more The application of an electronically steered thinned array L-band radiometer (ESTAR) for soil moisture mapping is investigated over the arid rangeland Walnut Gulch Watershed. Antecedent rainfall and evaporation for the flights are very different and result in a wide range of soil moisture conditions. The high spatial variability of rainfall events within this region results in moisture conditions with dramatic spatial patterns. Sensor performance is verified using two approaches. Microwave data are used in conjunction with a microwave emission model to predict soil moisture. These predictions are compared to ground observations of soil moisture. A second verification is possible using an extensive data set. Both tests showed that the ESTAR is capable of providing soil moisture with the same level of accuracy as existing systems.
[Proceedings] IGARSS'91 Remote Sensing: Global Monitoring for Earth Management, 1991
ABSTRACT
[Proceedings] IGARSS'91 Remote Sensing: Global Monitoring for Earth Management, 1991
ABSTRACT
[Proceedings] IGARSS '92 International Geoscience and Remote Sensing Symposium, 1992
The 21-cm Push Broom Microwave Radiometer (PBMR) was flown on 6 flights of the NASA C-130 to map ... more The 21-cm Push Broom Microwave Radiometer (PBMR) was flown on 6 flights of the NASA C-130 to map the surface soil moisture over the USDA Agricultural Research Service (ZLRS) Walnut Gulch experimental watershed in southeastern Arizona. It has four beams which cover a swath of 1.2 times the aircraft altitude, thus, by flying a series of parallel €light lines it
With the successful launch of the Terra satellite in December 1999 a new tool for observing land ... more With the successful launch of the Terra satellite in December 1999 a new tool for observing land surface properties became available, i.e. multispectral thermal infrared data from the Advanced Spaceborne Thermal Emission and Reflection (ASTER) radiometer. ASTER has 5 channels in the 8 to 12 micrometer wave band with 90 meter resolution. These data can be used to assess the spectral variations of surface emissivity. Knowledge of the surface emissivity is important for determining the radiation balance at the land surface. This is significant for arid lands with sparse vegetation because the emissivity of the exposed soils and rocks is highly variable. The results we will present are from ASTER data acquired over the Jornada Experimental Range in New Mexico during 2000, 2001 and 2002. The Jornada site is typical of a desert grassland where the main vegetation components are grass and shrubs with a large fraction of exposed soil. The Temperature Emissivity Separation (TES) algorithm is...
The land surface emissivity is often overlooked when considering surface properties that effect t... more The land surface emissivity is often overlooked when considering surface properties that effect the energy balance. However, knowledge of the emissivity in the window region is important for determining the longwave radiation balance and it subsequent effect on surface temperature. The longwave radiation balance is strongly affected by the difference between the temperature of the emitting surface and the sky brightness temperature, this difference will be the greatest in the window region. Outside the window region any changes in the emitted radiation by emissivity variability are mostly compensated for by changes in the reflected sky brightness. The emissivity variability is typically greatest in arid regions where the exposed soil and rock surfaces display the widest range of emissivity. For example the dune regions of the Sahara have emissivities of 0.7 or less in the 8 to 9 micrometer wavelength region due to the quartz sands of the region. The multispectral thermal infrared da...
Eos, Transactions American Geophysical Union, 1988
Journal of Glaciology, 1976
The microwave emission from a model snow field, consisting of randomly spaced ice spheres which s... more The microwave emission from a model snow field, consisting of randomly spaced ice spheres which scatter independently, is calculated. Mie scattering and radiative transfer theory are applied in a manner similar to that used in calculating microwave and optical properties of clouds. The extinction coefficient is computed as a function of both microwave wavelength and ice-particle radius. Volume scatter ing by the individual ice particles in the snow field significantly decreases the computed emission for particle radii greater than a few hundredths of the microwave wavelength. Since the mean annual temperature and the accumulation rate of dry polar fi rn mainly determine the grain sizes upon which the microwave emission depends, these two parameters account for the main features of the 1.55 cm emission observed from Greenland and Antarctica with the Nimbus-5 scanning radiometer. For snow particle sizes normally encountered, most of the calculated radiation emanates from a layer on the order of 10 m in thickness at a wavelength of 2.8 cm, and less at shorter wavelengths. A marked increase in emission from wet versus dry snow is pre dicted, a result which is consistent with observations. The model results indicate that the characteristic grain sizes in the radiating layers, dry-firn accumulation rates, areas of summer melting, and physical temperatures, can be determined from multispectral microwave observations.
IEEE International Geoscience and Remote Sensing Symposium, 2002
ABSTRACT
IGARSS '98. Sensing and Managing the Environment. 1998 IEEE International Geoscience and Remote Sensing. Symposium Proceedings. (Cat. No.98CH36174), 1998
The JORNada EXperiment (JORNEX) held at the Jornada Experimental Range in southern New Mexico aim... more The JORNada EXperiment (JORNEX) held at the Jornada Experimental Range in southern New Mexico aims at the description of the surface energy balance of a desert grassland ecosystem. A large array of both field and remote sensing data have been collected from 1995 to 1998. Remote sensing data collected consists of visible and thermal infrared imagery, video imagery and laser profiler data. These data are being used to infer land surface characteristics such as surface temperature, albedo and roughness. These land surface characteristics can be used as input for surface energy balance models coupled with atmospheric models. However atmospheric models work with very coarse grid cells of at least 50*50 km. Remote sensing data typically has a geometrical resolution much smaller than 50*50 km. In addition to the scale discrepancy, surface energy balance models are generally nonlinear algorithms, which amplifies scale problems. High resolution input data will not necessarily give the same results as low resolution input data. The problem arises of how to scale up the calculated surface energy balance fluxes to the much coarser resolution of the atmospheric model. The first step is to derive the length scales of the land surface characteristics involved in the calculation of the surface energy balance, therefore determining the maximum resolution required to sample the area. High resolution (~4m) NIR and TIR images with variogram and wavelet techniques will be used to study scaling
This study assesses the effects of physical structure and composition of shrub-coppice dune lands... more This study assesses the effects of physical structure and composition of shrub-coppice dune landscapes on anisotropy in the NASA MODIS-ASTER Airborne Simulator (MASTER) solar channels, and investigates the viability of simulating multi-angular data sets using off-nadir airborne imaging radiometry from a single overpass by means of data segmentation. Segmentation data are plant density and cover and spectral measures derived from high-resolution aerial photography and classified Landsat 7 Enhanced Thematic Mapper imagery. The directional signal contributes a variation of 5-10% in reflectance, necessitating angular corrections. For most areas the signal appears to differ only slightly with changes in landscape structure and composition because the view/illumination geometry is poor and reflectance is dominated by bright soils. Further work is required to determine whether simple models would be adequate for angular corrections.
The knowledge of surface fluxes is of prime interest in agronomy, meteorology and hydrology. Seve... more The knowledge of surface fluxes is of prime interest in agronomy, meteorology and hydrology. Several models were developed recently to estimate surface fluxes using remote sensing data. A possible way to distinguish these models is the decoupling or not of soil and vegetation components, which lead to label ``one layer'' or ``two layers'' models. Considering separate soil and vegetation components
The land surface emissivity is often overlooked when considering surface properties that effect t... more The land surface emissivity is often overlooked when considering surface properties that effect the energy balance. However, knowledge of the emissivity in the window region is important for determining the longwave radiation balance and its subsequent effect on surface temperature. The net longwave radiation (NLR) is strongly affected by the difference between the temperature of the emitting surface and the sky brightness temperature, this difference will be the greatest in the window region. Outside the window region any changes in the emitted radiation by emissivity variability are mostly compensated for by changes in the reflected sky brightness. The emissivity variability is typically greatest in arid regions where the exposed soil and rock surfaces display the widest range of emissivity. For example, the dune regions of North Africa have emissivities of 0.7 or less in the 8 to 9 micrometer wavelength band due to the quartz sands of the region, which can produce changes in NLR ...
Since the launch of NASA's Terra satellite in December 1999, the Advanced Spaceborne Thermal ... more Since the launch of NASA's Terra satellite in December 1999, the Advanced Spaceborne Thermal Emission and Reflection (ASTER) instrument has made a number of observations of the Elephant Butte Reservoir. The first observations were in June 2000 and the most recent were in October 2007. This period includes the recent drought conditions and the earlier full water conditions. The area of the reservoir was estimated for each of these scenes and compared with known water levels. The ASTER observations include both the visible reflectance and the thermal infrared emission (surface temperature). Both spectral regions can provide good contrast between the water and the surrounding land. This contrast makes the area estimation straightforward.
The application of an electronically steered thinned array L-band radiometer (ESTAR) for soil moi... more The application of an electronically steered thinned array L-band radiometer (ESTAR) for soil moisture mapping is investigated over the arid rangeland Walnut Gulch Watershed. Antecedent rainfall and evaporation for the flights are very different and result in a wide range of soil moisture conditions. The high spatial variability of rainfall events within this region results in moisture conditions with dramatic spatial patterns. Sensor performance is verified using two approaches. Microwave data are used in conjunction with a microwave emission model to predict soil moisture. These predictions are compared to ground observations of soil moisture. A second verification is possible using an extensive data set. Both tests showed that the ESTAR is capable of providing soil moisture with the same level of accuracy as existing systems.
[Proceedings] IGARSS'91 Remote Sensing: Global Monitoring for Earth Management, 1991
ABSTRACT
[Proceedings] IGARSS'91 Remote Sensing: Global Monitoring for Earth Management, 1991
ABSTRACT
[Proceedings] IGARSS '92 International Geoscience and Remote Sensing Symposium, 1992
The 21-cm Push Broom Microwave Radiometer (PBMR) was flown on 6 flights of the NASA C-130 to map ... more The 21-cm Push Broom Microwave Radiometer (PBMR) was flown on 6 flights of the NASA C-130 to map the surface soil moisture over the USDA Agricultural Research Service (ZLRS) Walnut Gulch experimental watershed in southeastern Arizona. It has four beams which cover a swath of 1.2 times the aircraft altitude, thus, by flying a series of parallel €light lines it
With the successful launch of the Terra satellite in December 1999 a new tool for observing land ... more With the successful launch of the Terra satellite in December 1999 a new tool for observing land surface properties became available, i.e. multispectral thermal infrared data from the Advanced Spaceborne Thermal Emission and Reflection (ASTER) radiometer. ASTER has 5 channels in the 8 to 12 micrometer wave band with 90 meter resolution. These data can be used to assess the spectral variations of surface emissivity. Knowledge of the surface emissivity is important for determining the radiation balance at the land surface. This is significant for arid lands with sparse vegetation because the emissivity of the exposed soils and rocks is highly variable. The results we will present are from ASTER data acquired over the Jornada Experimental Range in New Mexico during 2000, 2001 and 2002. The Jornada site is typical of a desert grassland where the main vegetation components are grass and shrubs with a large fraction of exposed soil. The Temperature Emissivity Separation (TES) algorithm is...
The land surface emissivity is often overlooked when considering surface properties that effect t... more The land surface emissivity is often overlooked when considering surface properties that effect the energy balance. However, knowledge of the emissivity in the window region is important for determining the longwave radiation balance and it subsequent effect on surface temperature. The longwave radiation balance is strongly affected by the difference between the temperature of the emitting surface and the sky brightness temperature, this difference will be the greatest in the window region. Outside the window region any changes in the emitted radiation by emissivity variability are mostly compensated for by changes in the reflected sky brightness. The emissivity variability is typically greatest in arid regions where the exposed soil and rock surfaces display the widest range of emissivity. For example the dune regions of the Sahara have emissivities of 0.7 or less in the 8 to 9 micrometer wavelength region due to the quartz sands of the region. The multispectral thermal infrared da...
Eos, Transactions American Geophysical Union, 1988
Journal of Glaciology, 1976
The microwave emission from a model snow field, consisting of randomly spaced ice spheres which s... more The microwave emission from a model snow field, consisting of randomly spaced ice spheres which scatter independently, is calculated. Mie scattering and radiative transfer theory are applied in a manner similar to that used in calculating microwave and optical properties of clouds. The extinction coefficient is computed as a function of both microwave wavelength and ice-particle radius. Volume scatter ing by the individual ice particles in the snow field significantly decreases the computed emission for particle radii greater than a few hundredths of the microwave wavelength. Since the mean annual temperature and the accumulation rate of dry polar fi rn mainly determine the grain sizes upon which the microwave emission depends, these two parameters account for the main features of the 1.55 cm emission observed from Greenland and Antarctica with the Nimbus-5 scanning radiometer. For snow particle sizes normally encountered, most of the calculated radiation emanates from a layer on the order of 10 m in thickness at a wavelength of 2.8 cm, and less at shorter wavelengths. A marked increase in emission from wet versus dry snow is pre dicted, a result which is consistent with observations. The model results indicate that the characteristic grain sizes in the radiating layers, dry-firn accumulation rates, areas of summer melting, and physical temperatures, can be determined from multispectral microwave observations.
IEEE International Geoscience and Remote Sensing Symposium, 2002
ABSTRACT