An inertial reference unit (IRU) is described which includes a processor programmed to provide inertial data from received inertial signals, a primary sensor unit providing the inertial signals to the processor, and an input/output (I/O) unit communicatively coupled to the processor. The I/O unit provides signals, including inertial data, to an external interface of the IRU and routes signals to and from the processor. The inertial reference unit also includes a secondary sensor unit separate fr...

A nautical instrument that can be repetitively mounted to and removed from a surface within a ship without the use of tools or other instruments. The nautical instrument incorporates a mounting system that achieves slidable locking engagement of the nautical instrument to a bulkhead plate that is permanently secured to the surface of the ship. In one embodiment, the invention comprises: a housing containing a gauge; a back plate connected to the housing and having a rear surface; a bracket assem...

The shipboard wave measurement system (SWMS) makes measurements as a function of time of vehicle position, range from the vehicle to the water's surface, and vehicle heave, pitch and roll to compute the height, direction, period and wavelength of the principal ocean wave component. Since the vehicle is moving, the wave heights measured are at different spatial locations, as well as at different times, and the observed wave height signal is Doppler shifted. The SWMS is composed of a positioning d...

The present invention is a system and method for automated position location using RF signposting. The present invention comprises a plurality of transmitting units placed throughout a service area. Each transmitting unit repeatedly transmits a signal including position information related to a position associated with the transmitting unit. The position information may be an absolute position or an encoded position based on the structure of a building in which the transmitting unit is located. ...

An atmospheric water vapor sensing system uses Global Positioning Satellites (GPS) to determine the refractivity and Slant-path Water Vapor Delay (SWD) between an Earth-based GPS receiver and a plurality of satellite-based GPS transmitters. The system provides improved precision in position calculation measurements by eliminating the refractivity effects of water vapor. No other system inputs are required apart from conventional GPS satellite signals and conventional satellite orbit data to impl...

A navigation system and method for diving operation in view of facilitating navigation under water to a specific location, in particular navigation back to a dive starting point, i.e., to the place from which the diving was started. The system includes a base station fixed to the starting point, such as a boat or equivalent, and arranged to transmit a signal to its environment, and a mobile unit carried along by the diver. The mobile unit includes a compass and a locating part which receives the...

A system and method for generating air flight data for an aircraft includes a network of substantially flush-mounted sensor modules which generate flow rate information and/or static pressure information for the many of the aircraft's aerodynamic surfaces, preferably near the respective leading edges of the aerodynamic surfaces. The generated flow rate information and static pressure information are collected by a remotely-located controller. A processor calculates desired air flight data, inclu...

A method of and apparatus for obtaining angle of attack, local static pressure and local pitot pressure from measured pressure values at ports of a probe having angle measuring ports with angle measuring axes lying in a plane and a pitot port having an axis lying along an axis in the plane bisecting the angle between the measuring ports. A table of known values of angle of attack relative to measured pressure ratio at measured Mach numbers determined by P.sub.1 /P.sub.m is stored in memory and u...

The present invention relates to back-up instruments for aiding the piloting of an aircraft, which instruments are intended to provide, with high security of operation, indications relating to the pressure altitude, the conventional speed and the attitude (angles of roll and of pitch) of the aircraft, this being for the purpose of serving both as reference for the control of the proper operation of the main systems of on-board and back-up instruments in the event of a fault with the main system ...

A navigational aid assists a person driving a vehicle in maintaining a desired distance from a reference line. It is particularly useful in navigating agricultural vehicles. The navigational aid includes an upright rail mounted adjacent a window in the cab of the vehicle. A marker is carried by the rail and may be positioned on the line of sight from the driver to the reference line. Driving the vehicle with the marker maintained on the line of sight keeps the vehicle at a constant distance from...