Abstract: Systems and methods are described, including a system (100) for automatically ascertaining a height characteristic of a contaminant (104) on a travel surface (102). The system (100) comprises an illumination and imaging device (106). At a first time, when the travel surface (102) is generally free of contaminant, the illumination and imaging device (106) illuminates the travel surface (102) with at least one light beam (119), and images at least one impingement of the at least one light beam (119). At a second time, when the travel surface (102) is covered by a layer of contaminant (104), the illumination and imaging device (106) illuminates the travel surface with a light beam (132), and images an impingement of the light beam on an impingement surface (107). In response to the imaging, a computer (130) calculates the height characteristic of the contaminant. Other embodiments are also described.

Abstract: Systems and methods are described, including a system (100) for automatically ascertaining a height characteristic of a contaminant (104) on a travel surface (102). The system (100) comprises an illumination and imaging device (106). At a first time, when the travel surface (102) is generally free of contaminant, the illumination and imaging device (106) illuminates the travel surface (102) with at least one light beam (119), and images at least one impingement of the at least one light beam (119). At a second time, when the travel surface (102) is covered by a layer of contaminant (104), the illumination and imaging device (106) illuminates the travel surface with a light beam (132), and images an impingement of the light beam on an impingement surface (107). In response to the imaging, a computer (130) calculates the height characteristic of the contaminant. Other embodiments are also described.

Abstract: A system and method for controlling mobile communication devices in a predefined coverage area is provided. One data processing system comprises a cell transceiver connected via a near field communication link to the mobile communication devices in the predefined coverage area and an application in each mobile communication device arranged to control functions of the mobile communication device responsive to the cell transceiver. The cell transceiver is arranged to communicate with the mobile communication devices in the predefined coverage area and thereby control the functions of the mobile communication devices in the predefined coverage area. The system establishes an automated control of the mobile communication devices using a bi-directional communication with the cell transceiver.