A method includes receiving an ambient pressure p1 measured at a time t1 by a mobile communication device at a geographic location g1. The method also includes receiving an ambient pressure p2 measured at time t2 within a ground level geographic location g2 near the geographic location g1. The method also includes receiving an indication of ambient pressure change between the time t1 and the time t2 from at least one geographic location within a maximum distance from the geographic location g1. The method also includes estimating an elevation of the mobile communication device at the time t1 using the indication of ambient pressure change between the time t1 and the time t2 to compensate an ambient pressure difference between the ambient pressure p1 and the ambient pressure p2. The method further outputs the estimated mobile device elevation.

A method includes receiving an ambient pressure p1 measured at a time t1 by a mobile communication device at a geographic location g1. The method also includes receiving an ambient pressure p2 measured at time t2 within a ground level geographic location g2 near the geographic location g1. The method also includes receiving an indication of ambient pressure change between the time t1 and the time t2 from at least one geographic location within a maximum distance from the geographic location g1. The method also includes estimating an elevation of the mobile communication device at the time t1 using the indication of ambient pressure change between the time t1 and the time t2 to compensate an ambient pressure difference between the ambient pressure p1 and the ambient pressure p2. The method further outputs the estimated mobile device elevation.

Techniques are provided for vision-based altitude estimation using one or more platform mounted cameras. An embodiment includes generating projected ground imagery of imagery provided by cameras of the platform, the projection based on a hypothesized altitude. The method also includes obtaining reference ground imagery based on the location of the platform, the location based on platform navigation data. The method further includes registering the projected ground imagery to the reference ground imagery and generating a match score associated with the registration. The method further includes selecting the hypothesized altitude as the estimated altitude based on the match score (e.g., if the match score exceeds a threshold value or is maximized over a set of hypothesized altitudes. The method may further include otherwise adjusting the hypothesized altitude and repeating the altitude estimation process based on the adjusted hypothesized altitude to search for an improved estimated altitude based on the match score.

Methods and apparatus to analyze desk heights are disclosed. A disclosed example apparatus includes a distance sensor to measure a distance from a computing device on a table surface to a floor surface, an orientation sensor to measure an orientation of the distance sensor relative to a direction of gravity, at least one memory, instructions, and processor circuitry to execute the instructions to calculate at least one of a first height of the table surface from the floor surface or a second height of at least a portion of the computing device to the floor surface based on the orientation and the distance.

A method and apparatus to adjust the angle of a surface is disclosed. The apparatus includes a measuring device having hardware components capable of generating a measurement of the position of the measuring device relative to the earth's gravity and circuitry capable of communicating the measurement to a controller and at least one electro-mechanical device capable of displacing the surface connected to the controller. The surface may be a bed and the present invention is particularly useful when the surface is a bed in a camper van. When the camper van is parked on a hill, the present invention provides a convenient method for making the bed inside the camper van level, or at an angle preferred by the user, for comfortable sleeping.

A method and apparatus to adjust the angle of a surface is disclosed. The apparatus includes a measuring device having hardware components capable of generating a measurement of the position of the measuring device relative to the earth's gravity and circuitry capable of communicating the measurement to a controller and at least one electro-mechanical device capable of displacing the surface connected to the controller. The surface may be a bed and the present invention is particularly useful when the surface is a bed in a camper van. When the camper van is parked on a hill, the present invention provides a convenient method for making the bed inside the camper van level, or at an angle preferred by the user, for comfortable sleeping.

A method is described that is implemented by computer for optimizing the vertical descent profile of an aircraft, the vertical profile being broken down into an altitude profile and a speed profile. One or more altitudes of passage can be determined by minimizing the overall deviation between the speed profile and one or more speed constraints previously received. The optimized descent profile can comprise one or more of these altitudes of passage. Different developments are described, in particular embodiments in which an optimized altitude of passage minimizes the engine thrust, the descent profile is of OPEN IDLE, FPA or VS type, the optimized descent profile is determined backward, a speed constraint is of AT or AT OR ABOVE type, and the use of the airbrakes. Display modalities are described, as are system and software aspects.

A floor height detection method is applied to a surveillance camera, and a surveillance image captured by the surveillance camera contains a surveillance region. The floor height detection method includes dividing the surveillance image at least into a first region and a second region, acquiring an actual installing height matrix of the surveillance camera upon the first region and the second region, and utilizing a matrix factorization algorithm to analyze the actual installing height matrix to acquire floor heights within the surveillance region.

A floor height detection method is applied to a surveillance camera, and a surveillance image captured by the surveillance camera contains a surveillance region. The floor height detection method includes dividing the surveillance image at least into a first region and a second region, acquiring an actual installing height matrix of the surveillance camera upon the first region and the second region, and utilizing a matrix factorization algorithm to analyze the actual installing height matrix to acquire floor heights within the surveillance region.

A passenger moving installation includes a plurality of tread elements forming an endless conveyor belt, wherein the tread elements are at least partially covered by at least one element that limits a transportation height of a user set of the installation. A safety system is configured to detect a risk of collision between the user set and the covering element. A method of determining a risk of collision between a user set and at least one covering element in a passenger moving installation at least partially covered by the covering element, includes determining the height of the user set in a monitoring area via a safety system, comparing the height of the user set to the height of a safety threshold, and triggering an event in the safety system if the user height exceeds the safety threshold.