Abstract. This paper presents the three-waveband spectrally agile technique (TWST) for measuring cloud optical depth (COD). TWST is a portable field-proven sensor and retrieval method offering a unique combination of fast (1 Hz) cloudresolving (0.5 • field of view) real-time-reported COD measurements. It entails ground-based measurement of visible and near-infrared (VNIR) zenith spectral radiances much like the Aerosol Robotic Network (AERONET) cloud-mode sensors. What is novel in our approach is that we employ absorption in the oxygen A-band as a means of resolving the COD ambiguity inherent in using up-looking spectral radiances. We describe the TWST sensor and algorithm, and assess their merits by comparison to AERONET cloud-mode measurements collected during the US Department of Energy's Atmospheric Radiation Measurements (ARM) TwoColumn Aerosol Project (TCAP). Spectral radiance agreement was better than 1 %, while a linear fit of COD yielded a slope of 0.905 (TWST reporting higher COD) and offset of −2.1.
We describe the software requirement and design specifications for all-sky
panoramic astronomical pipelines. The described software aims to meet the
specific needs of super-wide angle optics, and includes cosmic-ray hit
rejection, image compression, star recognition, sky opacity analysis, transient
detection and a web server allowing access to real-time and archived data. The
presented software is being regularly used for the pipeline processing of 11
all-sky cameras located in some of the world's premier observatories. We
encourage all-sky camera operators to use our software and/or our hosting
services and become part of the global Night Sky Live network.Comment: 1 figure. Accepted for publication in MNRA
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