CNPq/INPE-LANDSAT system report of activities

The status of the Brazilian LANDSAT facilities and the results achieved are presented. In addition, a LANDSAT product sales/distribution analysis is provided. Data recording and processing capabilities and planned products are addressed

The effects of solar incidence angle over digital processing of LANDSAT data

A technique to extract the topography modulation component from digital data is described. The enhancement process is based on the fact that the pixel contains two types of information: (1) reflectance variation due to the target; (2) reflectance variation due to the topography. In order to enhance the signal variation due to topography, the technique recommends the extraction from original LANDSAT data of the component resulting from target reflectance. Considering that the role of topographic modulation over the pixel information will vary with solar incidence angle, the results of this technique of digital processing will differ from one season to another, mainly in highly dissected topography. In this context, the effects of solar incidence angle over the topographic modulation technique were evaluated. Two sets of MSS/LANDSAT data, with solar elevation angles varying from 22 to 41 deg were selected to implement the digital processing at the Image-100 System. A secondary watershed (Rio Bocaina) draining into Rio Paraiba do Sul (Sao Paulo State) was selected as a test site. The results showed that the technique used was more appropriate to MSS data acquired under higher Sun elevation angles. Topographic modulation components applied to low Sun elevation angles lessens rather than enhances topography

A New Generation of Functional Polyisobutylenes for Advanced Applications

Polyisobutylene (PIB) is a fully saturated, aliphatic polymer of high commercial importance due to its superior gas barrier properties and high chemical/oxidative stability. One commercial end-use for PIB is in insulated glass windows (IGU), where it acts as a gas/moisture barrier and sealant. Under certain adverse conditions, catastrophic failure of the PIB sealant may result in aesthetic and functional failure of the IGU, which necessitates replacement of the unit. Thus, there exists a need to improve current generations of thermoplastic PIB sealants to be able to withstand the harsh environments found in current real-world applications. In the first project, we synthesized a library of PIB macromers bearing (meth)acrylate moieties via the acid catalyzed cleavage/alkylation of poly(isobutylene-co-isoprene) (butyl rubber) or via living polymerization and subsequent reactive end-quenching with phenoxyalkyl acrylates. The macromers were then crosslinked in the presence of a photoinitiator using UV light, and the curing kinetics were measured. The viscoelastic and tensile properties of the resulting networks were then tested and compared. In the second project, nitrile containing small molecules were added in the presence of cationized PIB chain ends to study their quenching efficiency. This technique, known as the Ritter reaction, represents a hitherto unreported route towards acrylamide functionalized telechelic PIBs. Under a variety of conditions, we demonstrated that PIB substrates were prone to carbocationic rearrangement rather than amide formation, but we successfully synthesized a new family of oligo-isbutenyl acrylamides via this route. In the third project, we demonstrated that quenchers derived from resorcinol, a commodity chemical derived from certain wood species, displayed superior quenching efficiency compared to known alkoxybenzenes. These quenchers were synthesized to possess a variety of functional groups, and the highly active phenyl ring allowed for quantitative quenching at significantly reduced time frames while simultaneously requiring lower Lewis acid demand compared to previously studied alkoxybenzenes. In the fourth project, we investigated the efficacy of 2,6-di-tert-butylphenol, a common antioxidant, as a quenching agent in the aforementioned cleavage/functionalization reaction. The resulting PIBs contained a mixture of mono- and di-tert-butylphenol moieties covalently bound to the PIB backbone and chain ends, which displayed superior resistance towards thermal and thermo-oxidative degradation compared to commercially available PIBs and PIBs synthesized via living polymerization

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

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

The Brazilian report to the 7th LANDSAT Technical Working Group (LTWG) meeting

Described is the current status of the INPE LANDSAT receiving and processing facilities, as well as the experience in the related activities during the period from June 1984 to February 1985

Automatic interpretation of MSS-LANDSAT data applied to coal refuse site studies in southern Santa Catarina State, Brazil

The coal mining district in southeastern Santa Catarina State is considered one of the most polluted areas of Brazil. The author has identified significant preliminary results on the application of MSS-LANDSAT digital data to monitor the coal refuse areas and its environmental consequences in this region

Sampling system for wheat (Triticum aestivum L) area estimation using digital LANDSAT MSS data and aerial photographs

A procedure to estimate wheat (Triticum aestivum L) area using sampling technique based on aerial photographs and digital LANDSAT MSS data is developed. Aerial photographs covering 720 square km are visually analyzed. To estimate wheat area, a regression approach is applied using different sample sizes and various sampling units. As the size of sampling unit decreased, the percentage of sampled area required to obtain similar estimation performance also decreased. The lowest percentage of the area sampled for wheat estimation with relatively high precision and accuracy through regression estimation is 13.90% using 10 square km as the sampling unit. Wheat area estimation using only aerial photographs is less precise and accurate than those obtained by regression estimation

Irrigated rice area estimation using remote sensing techniques: Project's proposal and preliminary results

The development of a methodology for annual estimates of irrigated rice crop in the State of Rio Grande do Sul, Brazil, using remote sensing techniques is proposed. The project involves interpretation, digital analysis, and sampling techniques of LANDSAT imagery. Results are discussed from a preliminary phase for identifying and evaluating irrigated rice crop areas in four counties of the State, for the crop year 1982/1983. This first phase involved just visual interpretation techniques of MSS/LANDSAT images