In one example a magnetometer unit comprises logic, to receive first magnetic response data from a first magnetic sensor and second magnetic response data from a second magnetic sensor displaced from the first magnetic sensor, generate a composite response surface representation from the first magnetic response data and the second magnetic response data, and store the composite response surface representation in a non-transitory memory. Other examples may be described.

The present invention relates to a method for calibrating magnetometers (20) of an object (1) moving in an ambient magnetic field, the method being characterised in that it comprises the steps of: (a) Acquisition by the magnetometers (20), of at least three measured components of the magnetic field around the magnetometers (20), and by inertial measurement means (11) which are secured to the object (1), of an angular velocity of the object (1); (c) Determination, by data processing means (21), of values of at least one calibration parameter of the magnetometers (20) minimising an expression defined by estimated components of the magnetic field and at least one magnetic equation relating to the angular velocity of the object (1), the estimated components of the magnetic field being a function of the measured components of the magnetic field as well as of calibration parameters of the magnetometers (20), and the at least one magnetic equation assuming that the magnetic field is uniform and stationary around the magnetic measurement means (20).

A technique for reducing altitude error involves determining a corrected altitude for an aircraft using forecast atmospheric pressure data available, for example, from a weather forecasting service. The forecast atmospheric pressure data includes, for a number of points in time and for a number of geographic locations, a set of pressure levels and corresponding altitude values. Altitude correction data is periodically calculated from the forecast atmospheric pressure data for each of a number of geographic grid points. Upon receiving aircraft position information and an aircraft altitude measurement for an aircraft, one or more of the geographic grid points corresponding to the aircraft position are identified, and a corrected altitude of the aircraft is determined based on the altitude correction data of the one or more geographic grid points.

An apparatus and method for estimating a three-dimensional (3D) position and orientation based on a sensor fusion process is provided. The method of estimating the 3D position and orientation may include estimating a strength-based position and a strength-based orientation of a remote apparatus when a plurality of strength information is received, based on an attenuation characteristic of a strength that varies based on a distance and orientation, estimating an inertia-based position and an inertia-based orientation of the remote apparatus by receiving a plurality of inertial information, and estimating a fused position based on a weighted-sum of the strength-based position and the inertia-based position, and to estimate a fused orientation based on a weighted-sum of the strength-based orientation and the inertia-based orientation. The strength-based position and the strength-based orientation may be estimated based on a plurality of adjusted strength information from which noise is removed using a plurality of previous strength information.

A method for computing a correction to a compass heading for a portable device worn or carried by a user is described. The method involves determining a heading for the device based on a compass reading, collecting data from one or more sensors, determining if the device is indoors or outdoors based on the collected data, and correcting the heading based on the determination of whether the device is indoors or outdoors.

A method for computing a correction to a compass heading for a portable device worn or carried by a user is described. The method involves determining a heading for the device based on a compass reading, collecting data from one or more sensors, determining if the device is indoors or outdoors based on the collected data, and correcting the heading based on the determination of whether the device is indoors or outdoors.

The present invention relates to a sensor suite comprising at least one sensor. More particularly, the present invention relates to a sensor suite for measuring absolute and/or relative position, location and orientation of an object on or in which the sensor suite is employed. The present invention further relates to improved, novel sensor types for use in the sensor suite. More particularly, the present invention relates to an improved, novel magnetometer that is self-calibrating and scalable. Still more particularly, the present invention relates to such a magnetometer that is miniaturized. Further embodiments of the present invention relate to systems and methods for providing location and guidance, and more particularly for providing location and guidance in environments where global position systems (GPS) are unavailable or unreliable (GPS denied and/or degraded environments).

Methods and systems for managing the orientation of the display of an aeronautical chart, notably towards Magnetic North or True North are provided. Rotational and/or translational tactile movements may manage the display of the chart. In one advantageous embodiment, the display screen is a haptic feedback screen (for example piezoelectric or MEMS microactuators), the North symbol rendered in relief is able to be manipulated with a single finger and the display device is stabilized by at least partially compensating for the turbulence experienced by the cockpit. Some software aspects are described.

Methods and systems for managing the orientation of the display of an aeronautical chart, notably towards Magnetic North or True North are provided. Rotational and/or translational tactile movements may manage the display of the chart. In one advantageous embodiment, the display screen is a haptic feedback screen (for example piezoelectric or MEMS microactuators), the North symbol rendered in relief is able to be manipulated with a single finger and the display device is stabilized by at least partially compensating for the turbulence experienced by the cockpit. Some software aspects are described.

A navigation instrument including an orientation angle calculation unit, in particular the first and second orientation angles, wherein the orientation angle calculation unit is configured to be able to determine the first and second orientation angles in a given order and also in reverse order; and wherein the calculation unit is arranged to be able to choose between said given order and said reverse order, to calculate the first and second orientation angles, based on a comparison between an indicator of a risk of error, quantifying a risk of instability of said unit during the determination of the first and second orientation angles, and a predetermined threshold.