Abstract: A visibility measurement system that computes relative visibility by comparing an images of an environment against a benchmark image. A sensing device receives an image and a digital conversion system maps the image into a two-dimensional data array. A processor converts the digital data to a value that represents visibility by identifying a region in the image that has a uniform distance from the sensing device over time, computing a benchmark visibility index for the region as a summation of measurable visual characteristics that influence visibility in the region under a benchmark environmental condition, computing a second visibility index for a second environmental condition, and computing a relative visibility value as the ration of the second visibility index in relation to the benchmark visibility index.

Abstract: A video camera based atmospheric visibility measurement system that is capable of providing automated measurements of atmospheric visibility during both the day and night. For daylight measurements, the system views an image that has contrasting portions. A representative contrast signal is generated for contrasting portions of the images. The representative contrast number is used to generate an exponential curve of contrast levels versus distance. Atmospheric visibility is determined by detecting where the exponential curve reaches a threshold of visibility.

Abstract: A visibility measurement system that computes relative visibility by comparing an images of an environment against a benchmark image. A sensing device receives an image and a digital conversion system maps the image into a two-dimensional data array. A processor converts the digital data to a value that represents visibility by identifying a region in the image that has a uniform distance from the sensing device over time, computing a benchmark visibility index for the region as a summation of measurable visual characteristics that influence visibility in the region under a benchmark environmental condition, computing a second visibility index for a second environmental condition, and computing a relative visibility value as the ration of the second visibility index in relation to the benchmark visibility index.

Abstract: A video camera based atmospheric visibility measurement system that is capable of providing automated measurements of atmospheric visibility during both the day and night. For daylight measurements, the system views a series of progressively larger targets that have contrasting portions. A representative contrast signal is generated for each target that may comprise an average of the highest contrast levels detected for each target. The representative contrast number is used to generate an exponential curve of contrast levels versus distance. Atmospheric visibility is determined by detecting where the exponential curve reaches a threshold of visibility. For night measurements, the intensity values of an image of a light source are detected and another exponential curve is produced that indicates the amount of light scattering. The visibility is proportional to an exponential constant of the curve.