Abstract: An aircraft 160 approaches a landing point 162 following a flight path 164 to a designation point 166, the pilot sights the landing point 162 and activates the apparatus. A first calculation of coordinates for the landing point 162 is made and landing symbology generated. The pilot reviews the landing symbology and decides whether or not there is an acceptable correlation with the landing point 162. If not, the pilot will continue along the flight path 164 activating the apparatus at further designation points 168, 170 and 172 to reduce the designation error between the coordinates calculated by the apparatus and the real world landing position 162 observed by the pilot until the pilot is satisfied. At this point the pilot enters a landing phase and the symbology provides the pilot with landing cues even when the helicopter 160 enters a brown out event indicated by cloud 174.

Abstract: An element that is sensitive to a pressure or acceleration signal comprises an optical element capable of changing its index of refraction and/or path length in response to a time varying pressure or in response to acceleration and a pliant mounting member supporting the optical element. The mounting member changes its geometrical configuration in response to the time varying pressure or acceleration. Some embodiments of the invention use a mechanical amplifier to achieve the needed sensitivity.

Abstract: A two- or three-component measuring accelerometer based on an operating principle entirely different from that of conventional accelerometers is realized with a simple arrangement and provided as a two- or three-component measuring seismometer. Planar optical fiber rolls (2) whose light propagation characteristics change sensitively in response to changes in the pressure applied thereto are split into more than three separate sections and disposed at the bottom of a columnar or polygonal prism-shaped load member (1). Changes in acceleration acting on the load member (1) are measured on the basis of differences between the light propagation characteristics of the split optical fiber rolls (2-1 to 2-4).

Abstract: An arrangement of a speed sensor on a personal watercraft better shields the sensor from damage while simplifying the layout and arrangement of the sensor on the underside of the watercraft hull. The hull includes a pump chamber formed in part by a front wall. The speed sensor is attached to the wall with a portion of the sensor projecting below a housing of the sensor. A ride plate covers a lower opening of the pump chamber and fits about the sensor housing. In this location, the speed sensor does not interfere with the arrangement or operation of steering or trim mechanisms used with a jet propulsion unit housed within the pump chamber. The speed sensor also is generally protected in this location and is not visible from the rear of the watercraft to improve the watercraft's aesthetics.

Abstract: A method is described for controlling the magnetic field strength of an electromagnetic geophone by: a) providing a specified center value each for a geophone sensitivity parameter and a geophone damping parameter; b) magnetizing an electromagnetic geophone to full saturation of the magnet; c) measuring the value each for the fully saturated geophone sensitivity parameter and damping parameter; d) partially demagnetizing the geophone; e) measuring the value each for the partially demagnetized geophone sensitivity and damping parameters; f) calculating a slope for a geophone demagnetization line representing geophone demagnetization versus demagnetizing force by utilizing the measured fully saturated geophone sensitivity and damping parameters as one point on the line and utilizing the measured partially demagnetized geophone sensitivity parameter and damping parameter as another point on the line; and g) calculating an amount of demagnetization required to provide the geophone with sensitivity and damping par

Abstract: A through-hull speed sensor of the magnetized paddlewheel sensor type wherein a paddlewheel is rotatably supported in a cavity adjacent a magnetic sensing device which generates electrical pulses corresponding to paddlewheel speed as the wheel rotates when the vessel moves through water. The sensor has improved linearity provided by a flow channel recessed in a downstream surface of a sensor mounting member. The recessed flow channel raises the trailing edge above the leading edge, thereby reducing pressure on a back wall of the cavity where the pressure is due to fluid flow through the paddlewheel.

Abstract: A through-hull speed sensor of the magnetized paddlewheel sensor type wherein a paddlewheel is rotatably supported in a cavity adjacent a magnetic sensing device which generates electrical pulses corresponding to paddlewheel speed as the wheel rotates when the vessel moves through water. The sensor has improved low speed characteristics provided by a housing which extends the paddlewheel into the water below the hull. The bow of the housing provides a new leading edge, generating a smaller thickness boundary layer at the paddlewheel, so that the paddles project beyond the layer at low speeds. High speed performance is improved by having a high ratio of paddle fore-to-aft drag coefficient shape; keeping the periphery of the paddlewheel hub within, or flush with, the bottom of the cavity; a low paddle projection versus paddlewheel radius ratio; and by keeping the ratio of paddle cross-section versus available cavity cross-sectional space within an optimum range.

Abstract: An apparatus for measuring and displaying the speed of a craft, especially of a sailboard, comprises on one hand an immersed rotator (1) equipped with a permanent magnet and attached to the craft (40) and on the other hand a measuring device mounted on the craft. The measuring device comprises a coil having a very large number of turns, at least one operational amplifier and a frequency meter for determining the frequency of rotation of the magnetic field produced by the magnet of the rotator (1). A sealed box (30) encloses the entire measuring device, its liquid crystal display unit and photovoltaic cells for its power supply. The apparatus is particularly adapted to be removably mounted on a sailboard or a light dinghy.

Abstract: This troll meter is used to determine the speed of a boat in the range of one to three knots. Primarily, it consists of a shaft having three marked and different pitched propellers, which are rotated by the forward speed of the boat, and each is freely and rotatably received on shaft 11.

Abstract: A display system for indicating sailing data to an operator of a small sized sailing boat in which a speed sensor in the hull transmits pulses to a speed measuring device which stores the data in a memory. The sailing data is periodically transmitted to a receiver worn by the boat operator either on his wrist or some conveniently viewable position.

Abstract: A water speed sensing transmitter unit suspended from a fishing boat at the depth fishing gear is being trolled actuates transmission of a pulse signal through the water for detection by a receiver unit mounted on the boat. The frequency of the pulse signal is proportional to the speed of the transmitter unit relative to surrounding water at the trolling depth. The receiver unit recreates a corresponding pulse signal, averages it and triggers a display of the average speed sensed by the transmitter unit over a predetermined period.

Abstract: A water flow meter having a hollow housing adapted to contain counter mechanism, a propeller shaft extending into the housing, a hollow propeller hub mounted on the free end of the shaft, an opening in the hub, a bore extending through the shaft from the hub to the housing, a flexible diaphragm extending over the bore in the hub adapted to contain a liquid lubricant capable of flowing to and from the housing effected by changes in temperature and pressure and seal means mounted on the housing and extending about the shaft preventing the ingress of water therethrough.