LUMINANCE-TO-INTENSITY MEASUREMENT METHOD

Recently a method has been developed for estimating source intensity u sing a luminance meter in cases where the target source is very small and does not fill the aperture of the luminance meter. The target may be a single source or a collection of sources used to create a symbol. The method involves measuring the target source with a luminance mete r and using the resulting luminance measure to calculate the estimated intensity of the entire source. Similar to converting an illumination measure to intensity, this method requires that the measurement dista nce be known. In addition, the size of the luminance meter aperture mu st also be known. Laboratory and field tests have been conducted which validate tile method, as well as establish a measurement procedure. A lthough initially developed for nighttime data collection purposes, th e method has been successfully used for daytime signal intensity measu rements. A major advantage of this measurement method is that it allow s for direct data collection within a global frame of reference. That is, aside from the distance between the signal and the observer, no ot her geometric information is required. The research paper is completel y written and includes a mathematical overview and measurement procedu re for the method. Also included are descriptions of the validation te sts, the collected data and results, and a discussion of possible appl ications.