A comparison between maritime field observations and photosimulation for developing and validating visible signature evaluation tools

Over the past 50 years, the majority of detection models used to assess visible signatures have been developed and validated using static imagery. Some of these models are the German developed CAMAELEON (CAMou age Assessment by Evaluation of Local Energy Spatial Frequency and OrieNtation) model and the U.S. Army's Night Vision and Electronic Sensors Directorate (NVESD) ACQUIRE and TTP (Targeting Task Performance) models. All these models gathered the necessary human observer data for development and validation from static images in photosimulation experiments. In this paper, we compare the results of a field observation trial to a static photosimulation experiment. The probability of detection obtained from the field observation trial was compared to the detection probability obtained from the static photosimulation trial. The comparison showed good correlation between the field trial and the static image photosimulation detection probabilities, where a Spearman correlation coefficient of 0.59 was calculated. The photosimulation detection task was found to be significantly harder than the field observation detection task, suggesting that to use static image photosimulation to develop and validate maritime visible signature evaluation tools may need correction to represent detection in field observations.