Radiometric comparison of the LANDSAT-5 TM and MSS sensors

Abstract

This paper analyses the radiometric accuracy of LANDSAT-5 Thematic Mapper (TM) data and of LANDSAT-5 Multispectral Scanner (MSS) data, using concurrent TM and MSS images recorded simultaneously over the city of Montreal, Quebec, Canada. The data sets were obtained from the Canada Centre for Remote Sensing (CCRS), and have been preprocessed for geometric correction, and for radiometric 23calibration utilizing the in-flight calibration lamp data. The comparison of the TM and MSS normalized apparent reflectances computed for 12 different typical cover types using the post-launch calibration dynamic ranges shows the relevance of the CCRS processing systems. The significant linear regressions, obtained between channels from the two sensors, and the analysis of the ground reflectance corrected for atmospheric absorption and scattering as well as for pixel adjacency effects, can serve both to assess detector degradation with time and to rescale data to match those from other LANDSAT sensors.     

CONTAMINATION OF SEVERAL BREAKFAST CEREALS BY METHYL CHLOROFORM

The analysis of several breakfast cereals has shown that methyl chloroform (MCF, 1,1,1-Trichloroethane), a solvent found to be present in the adhesive of the outer box, can migrate from the adhesive through the box and the waxed liner into the cereal. The levels of MCF in the adhesive, the outer box, the waxed liner and the cereal were found to range from 0 to 2.3%, 0 to 19.4 ppm, 0 to 4.8 ppm, and 0 to 0.40 ppm, respectively, in 11 breakfast cereals. The MCF residues were determined using a closed system-vacuum distillation gas chromatographic technique with both electron capture and electrolytic conductivity detection. The results were confirmed by high resolution mass spectrometry.     

DETINNING IN CANNED TOMATOES CAUSED BY ACCUMULATIONS OF NITRATE IN THE FRUIT

ABSTRACT— The 1965 experimental crop of Floradel variety tomatoes accumulated no nitrate and removed only about 15% of the tin from their containers in a 2-yr storage period. The 1966 Florida crop of Homestead 24 variety tomatoes accumulated from about 50–80 ppm in the fruit and removed about 70% of the tin from their cans. All fertilizer application variables except the lowest resulted in about the same level of nitrate accumulation. The nitrate in most of these variables was exhausted in about 6 mo and the rate of detinning leveled off soon after. The correlation between loss of nitrate and tin removal was significant at the 5% level. Detinning in these cans approached a "problem level' in that about 70% of the tin was removed in 18 mo. In the 1965 tomato crop at Ohio State University there was no apparent connection between the levels of applied nitrogen and the nitrate accumulated in the fruit. In the 1966 Ohio tomatoes, the treatments with no applied nitrogen accumulated less nitrate in the fruit than the other treatments with varying levels of nitrate fertilization. The differences among the detinning histories of the various treatments followed in a general way the differences in nitrate accumulation. Detinning in individual cans varied between extremely wide limits. There were no differences apparent among the treatment variables in the 1965 crop. In the 1966 tomatoes the zero applied nitrogen treatment consistently showed less detinning than the others. In both the 1965 and 1966 crops the nitrate in the canned samples was exhausted after about 2 mo of storage. Essentially all of the detinning in these tomatoes occurred during the first 6 mo. Regression equations from pooled results of field studies and work on nitrate fortification of non-aggressive tomatoes suggest that an initial nitrate concentration of the order of 100 ppm can constitute a rapid detinning problem in tomatoes in a 303 can having a tin coating weight of 1.00 Ib/bb.     

Estimation of Bacterial Quality of Cod Fillets with the Disc Flotation Method

Spoilage bacteria of cod fillets were desorbed off the fillet surface by ultrasonication. Catalase activity of these bacteria was determined using the disc flotation method after selective heat inactivation of the endogenous cod catalase and then correlated with the colony forming units. The method was applied to cod fillets from ten retail sources with satisfactory results.