IEEE International Geoscience and Remote Sensing Symposium

In order to retrieve land surface component temperature from multi-spectral remote sensing images, such as ASTER, we choose a component equivalent emissivity model, and iterative linear regression inversion algorithm. The method is tested with ASTER image of VNIR and TIR channels, as well as supplementary and validation data acquired from ground experiment. The atmospheric effect is corrected with the dark-object method; surface structural information is derived from ASTER VNIR observations; component emissivity is measured in situ with the BOMEN MR-154 spectrometer; validation data are also measured in ground experiments. Finally, the accuracy of the results and sources of error are analyzed.

The Moderate Resolution Imaging Spectroradiometer (MODIS) contains 36 bands from the visible to the thermal infrared with the nominal ground field of views of 250 m, 500 m and 1 km. This paper summarizes the changes to the MODIS Earth location algorithm and geometric parameters since the launch of MODIS on the Terra spacecraft in December 1999. Detailed analysis of residuals from a global network of ground control points reveals biases in unexpected areas of the MODIS geometric model. For instance, systematic off-nadir along-track errors are best modeled by a tilt in the mirror coordinate system. Analysis also indicates that some along-track errors are possibly caused by uncertainty in spacecraft attitude estimates. We discuss how reducing these errors enable sub-pixel geolocation accuracy goals to be achieved.

Reports on research to adapt the 2/sup nd/ Generation Prairie Agrometeorological Model for wheat developed by Raddatz (1993) at Environment Canada to use both in situ data from a distributed network of meteorological stations (original mode) and NOAA AVHRR information output from the GeoComp-N processor at the Manitoba Remote Sensing Centre. Two parameters previously approximated by the model have been substituted with AVHRR derived information: fractional leaf area, and skin temperature. These parameters are critical for obtaining accurate outputs. Model outputs were ingested into a GIS to generate maps of crop growth stage expressed as biometeorological time, actual evapotranspiration or crop water-use, and top zone and root zone soil moisture for a test area in southern Manitoba for the year 2000 growing season.

The present research focuses on coupling thermophysical variables over smooth landfast first-year sea ice with its microwave emissions. A surface based radiometer (SBR) was used to collect microwave emissions on 19-, 37- and 85 GHz, both vertical and horizontal polarizations over a fixed area. Data were collected during the Collaborative-Interdisciplinary Cryospheric Experiment (C-ICE) between May 15 and June 25, 2000, in the Canadian High Arctic. It expands from winter-like ice environment to advanced melt. Analysis was conducted in a seasonal basis taking into consideration observed changes in the physical characteristics of the sea-ice. Winter was represented by thick, stable, snow-covered sea-ice, followed by three melt-pond stages: ablation 1, ablation 2/3, and ablation 4, following the characterization described in Yackel (2001).

Radio frequency interference (RFI) limits the sensitivity of microwave radiometry by limiting the usable bandwidth and effective integration time of measurements. Adaptive canceling techniques offer a look-through capability that can potentially ease these constraints. Empirical arguments are used to determine the best possible attenuation of RFI for any canceler. Some field results using two different canceling methods are presented and shown to be consistent with this performance bound.

Following the 1997 flood, the Red River Basin Task Force recommended the development of an international geospatial database. This database will consist of remotely sensed and GIS data that will eventually be implemented in the decision support system, to improve forecasting and modelling of the Red River basin. This project demonstrates the cross border issues and challenges encountered in the process of merging roads and hydrography vectors from Canadian and US federal governments. The major differences in the datasets between countries are: classification systems, details of attributes, validation dates, and mapping scales. Discrepancies include: horizontal offsets, feature density variations, feature discontinuities, and attribute discontinuities at the border. Flood extent vectors were extracted from RADARSAT images to provide an overview of flood extent at specific time within the Red River basin.

The ability to selectively apply herbicides through the use of weed mapping and variable rate sprayers offers the potential to reduce harmful effects on the environment as well as to optimize producer profitability. Over the past 25 years, there have been numerous studies involving remote sensing and weed/crop discrimination. With the development of greater spectral and spatial resolution sensors and spectral mixture analysis techniques re-investigation of the discrimination of weed and crop species present in cultivated systems appears timely. In a laboratory experiment, the spectral separability of five weeds and two crops of economic importance on the Canadian prairies was investigated. Reflectance from the uppermost fully expanded leaves of field grown plants was examined over the range 350-2500 nm using a field spectroradiometer and an integrating sphere. The various plant species were not separable using the broad bands present on the Landsat TM satellite. However, the weed/crop species could be discriminated using reflectance in approximately 30 10-nm wide bands across the electromagnetic spectrum. Results suggest that hyper-spectral remote sensing could be used for weed/crop mapping and merits further study under field conditions.

Climatological time-series of tropospheric temperatures from the Microwave Sounding Unit (MSU) are potentially of great value in validating observations of climate change due to their excellent spatial and temporal coverage. However, the long-term trend signal is small relative to natural seasonal and inter-annual variability and inter-satellite biases, and is comparable to diurnal temperature drift arising from variation of the satellite local crossing time. Additional effects due to time-varying non-linear instrument response also contribute to instrument error. We discuss a consistent methodology for compensating for these factors and present an error model quantifying their significance in determination of long-term trends.

Doping of the lead telluride and related alloys with the group III impurities results in appearance of unique physical features of the material, such as persistent photoresponse, enhanced responsive quantum efficiency (up to 100 photoelectrons/incident photon), radiation hardness and many others. We review physical principles of operation of the photodetecting devices based on the group III-doped IV-VI including possibilities of fast quenching of the persistent photoresponse, construction of a focal-plane array, new readout technique, and others. Comparison of performance of the state of the art Ge(Ga) and Si(Sb) photodetectors with their lead telluride-based analogs shows that the responsivity of PbSnTe(In) photodetectors is by several orders of magnitude higher. High photoresponse is detected at the wavelength 116 micrometers in PbSnTe(In), and it is possible that the photoconductivity spectrum covers all the submillimeter wavelength range.

The NPOESS program will include a ground data processing system that is designed from the outset to provide outstanding speed and flexibility in product delivery to its users.