Patent ID: 8098367

Claim:
A system for estimating an elevation of a vehicle, the system comprising: a laser source, comprising: a rotating laser emitter configured to emit a spot beam having a slope that is adjustable by the laser source; and a first radio frequency communication (“RF”) transceiver; and a mobile station configured to be mounted on a moving vehicle, the mobile station comprising: a laser detector, comprising a substantially vertical array of laser sensors; a global navigation satellite system (“GNSS”) receiver; a second RF transceiver; and a processing system comprising a processor and a computer-readable medium having encoded thereon a set of instructions executable by the computer system to perform one or more operations, the set of instructions comprising: instructions to establish an upper threshold value corresponding to a first portion of the array of laser sensors; instructions to establish a lower threshold value corresponding to a second portion of the array of laser sensors; instructions to receive input data from the laser detector; instructions to determine, based on the input data, a laser strike location value corresponding to a portion of the laser detector receiving the spot beam emitted by the laser emitter; instructions to compare the laser strike location value with at least one threshold value selected from the group consisting of the upper threshold value and the lower threshold value; instructions to determine, based at least in part on a comparison of the laser strike location value with the at least one threshold value, an amount by which the slope of spot beam emitted by the laser emitter should be adjusted; and instructions to transmit, via the second RF transceiver, a notification for reception by the first RF transceiver, the notification instructing the laser source to adjust the slope of the spot beam by the determined amount; wherein the laser source is configured to adjust, upon receipt of the notification, the slope of the spot beam over a period during which the spot beam will not be received by the laser detector, and to transmit a message informing the mobile station of an adjusted slope of the spot beam emitted by the laser emitter; and wherein the set of instructions further comprise: instructions to determine, based on input from the GNSS receiver, a position of the mobile station; and instructions to calculate an elevation of the mobile station, based at least in part on the adjusted slope of spot beam emitted by the rotating laser emitter, the position of the mobile station, a position of the laser source, and input data received from the laser detector.