The Enhanced Night Visibility (ENV) project is a series of experiments undertaken to investigate different visual enhancement systems (VES) for the nighttime driving task. The purpose of this characterization activity is to establish the photometric nature of the objects presented to the observer during the ENV Phase III studies, which assessed headlamp beam patterns as well as the influence of infrared (IR) technology on object detection. The photometric measurements of interest are the object luminance and the background luminance. Other calculated parameters were established such as object contrast with the background and object visibility level. The measurements were taken at the threshold of detection and calculated for three visible-light VESs and three IR VESs. For the visible-light VESs, the photometric data showed the influence of the headlamp distribution and the suitability of the various metrics to predict object visibility. For the IR systems, the data gave an indication of the usage of the in-vehicle systems and their distraction level for the driver. (Author/publisher)
Abstract