Cloud Detection for Night-Time Panchromatic Visible and Near-Infrared Satellite Imagery

Abstract

Abstract. Cloud detection for night-time panchromatic visible and near-infrared (VNIR) satellite imagery is typically performed based on synchronized observations in the thermal infrared (TIR). To be independent of TIR and to improve existing algorithms, we realize and analyze cloud detection based on VNIR only, here NPP/VIIRS/DNB observations. Using Random Forest for classifying cloud vs. clear and focusing on urban areas, we illustrate the importance of features describing a) the scattering by clouds especially over urban areas with their inhomogeneous light emissions and b) the normalized differences between Earth’s surface and cloud albedo especially in presence of Moon illumination. The analyses substantiate the influences of a) the training site and scene selections and b) the consideration of single scene or multi-temporal scene features on the results for the test sites. As test sites, diverse urban areas and the challenging land covers ocean, desert, and snow are considered. Accuracies of up to 85% are achieved for urban test sites.

Optimized Performance Parameters for Nighttime Multispectral Satellite Imagery to Analyze Lightings in Urban Areas

“…Since the focus is on cloud-free conditions, only such atmospheres are considered. How to differentiate between cloud-covered and cloud-free conditions even solely based on panchromatic images is illustrated by [24] especially for urban areas with high accuracy. Since the focus is on urban areas, urban aerosols and atmospheric profiles mid-latitude summer, mid-latitude winter, subarctic summer, subarctic winter, and tropical are included to cover a wide range of conditions.…”