Impacts of Radiance Quantization on Surface Mapping: Comparisons among the Landsat Sensors

Abstract

Radiance quantization and dynamic ranges are considered the basic characteristics of a sensor in radiometry. However, their impacts on surface mapping have not been fully investigated and understood (e.g., for different Landsat sensors), while much attention has been paid to the impacts related to other aspects (e.g., spatial resolution, the wavelength of spectral channels, and several spectral channels). In this paper, a synthesized data collection of multispectral reflectance and radiance (with and without considering actual quantization) for the Landsat sensors from hyperspectral records was generated. Based on the synthesized data, the impacts of radiance quantization were discussed in terms of channel reflectance and spectral indices. As the preliminary findings show, the quantization effects on channel reflectance vary among channels, presenting different impacts on spectral indices correspondingly, which affect the measures of between-sensor difference. It also suggests that the effects of quantization may relate to land surface conditions (e.g., land use and land cover) in addition to the sensor characteristics.