Multitemporal Multispectral Scanner Research Articles

A Landsat MSS time series model and its applications in geological mapping

Although temporal factors in remotely sensed data have long been recognized by remote sensing scientists, studies on the separation of temporal and stable factors have been very limited. Applications of the time-variant characteristics of the data are also limited in the environmental monitoring and change detection fields. The merits and applications of the stable factors in the time-variant historical image data or image time series have not been fully recognized. This paper presents a time-variant model for the historical multitemporal multispectral scanner (MSS) data and a technique for processing the image time series for geological mapping. This model has been successfully applied to the surface geological mapping of a region in central eastern Nevada, USA.

The quantity of biomass burned in southern Africa

Abstract. A new method is described for calculating the amount of biomass burned, its type and location, and the time of burning. Active fires in 1989 were detected using daily advanced very high resolution radiometer (AVHRR) satellite imagery. The fire count was calibrated to area burned using a stratified sample of multitemporal multispectral scanner (MSS) imagery. The calibration factor is strongly dependent on mean individual fire area, which is in turn strongly related to cumulative normalized difference vegetation index (NDVI). The best available vegetation maps for southern hemisphere Africa were combined and reclassified into functional vegetation types with a similar fire ecology. The fuel load was calculated in each 0.5° × 0.5° grid square using a production model specific for each vegetation type, driven by monthly rainfall data. Multiyear fuel accumulation, herbivory, and decay were accounted for. Combustion completeness was modeled as a function of fuel mass and fuel type, established from field‐collected data. The method was compared to the conventional procedure for calculating biomass burned, based on classification. The estimated amount of biomass burned in vegetation fires in southern hemisphere Africa annually is 90–264 Tg dry matter (DM) by the new modeling method and 247–2719 Tg DM by the conventional classification method. The modeling method is conservative since it does not include burning due to forest clearing or the burning of agricultural waste or domestic biomass fuels, but it is believed to be more realistic than the classification method and provides space‐and‐time‐resolved output. The bulk of the burning occurs between June and September, with a peak in August. Half of the burning takes place in the broad‐leaved, low‐nutrient‐status savannas which dominate the zone between 5° and 18°S.