Moon Phase Consideration for Relative Correction and its Application to VIIRS Boat Detection

Abstract

Awareness of boats has been the main issue in areas of fisheries management, illegal fishing, and maritime traffic, etc. For the awareness, Automatic Identification System (AIS) and Vessel-Pass System (V-PASS) have been widely used to collect the information related boats. However, it is hard to collect the precise information by only using these systems. Recently, satellite-based data has been increasingly used as a cooperative system. In 2015, U.S. National Oceanic and Atmospheric Administration (NOAA) developed a detection algorithm using the Visible Infrared Imaging Radiometer Suite (VIIRS) Day & Night Band (DNB) data. Although the detections are highly available and used in many publications, it is difficult to estimate the night-time fishing boats immediately. Particularly, it is hard to estimate the threshold due to the lunar irradiation effect. Therefore, it is necessary to correct this effect for the application of single specific threshold. In this study, moon phase is regarded as the major frequency of this effect. Considering the moon phase, the relational expressions are derived and then used as the offset for relative correction. As a result of correction, the standard deviation of the thresholds was significantly decreased against the thresholds of NOAA. Additionally, a constant threshold can be set without determination of different thresholds each day. Ultimately, regardless of the moon phase, this study can achieve the detection applying a single specific threshold.