This invention relates to a rotatable device having two arms rotatably connected about a hollow hub wherein the arms include a cable extending through a passageway and the hub so as to minimize bending of the cables about each other when the arms are in a compact position. In particular this invention relates to a foldable GPS compass and a method relating thereto to present a compact folded device that is easier to install with minimal bending of the cables. The invention also discloses a detent disposed within the hub for accurate selective placement of the arms and method relating thereto.

Disclosed are a system and method for undersea navigation with a maritime vehicle or diver undersea navigation device. A sensor interface receives navigation information from a plurality of sensors used to sense navigation information. A processor receives the navigation information from the sensor interface. The processor converts the navigation information into graphics data. The processor provides the graphics data to a graphics processing unit to render a navigation board image on a display of the maritime vehicle or diver undersea navigation device. The navigation board image comprises a plurality of navigation indicators to indicate the navigation information and a compass comprising a plurality of rotational orientation indicators to indicate rotational orientation information. The rotational orientation indicators include a plurality of heading direction indicators, a current heading indicator, and a plurality of pitch indicators, where the plurality of pitch indicators indicate pitch information.

In an embodiment, a method and system are provided for determining a pedestrian position via dead reckoning on a portable device carried by the pedestrian (or user). The device has at least a processor, a 3D accelerometer, and a 3D gyroscope. The 3D accelerometer, and a 3D gyroscope are sampled to calculate device orientation, and then 3D accelerometer samples are gathered during a sensor time frame and an average step frequency is calculated. The user's speed and direction of movement are estimated and a device velocity is calculated relative to a prior device velocity via dead-reckoning. The estimated device velocity is corrected for drift and the pedestrian position is calculated based on the corrected estimated current device velocity.

In an embodiment, a method and system are provided for determining a pedestrian position via dead reckoning on a portable device carried by the pedestrian (or user). The device has at least a processor, a 3D accelerometer, and a 3D gyroscope. The 3D accelerometer, and a 3D gyroscope are sampled to calculate device orientation, and then 3D accelerometer samples are gathered during a sensor time frame and an average step frequency is calculated. The user's speed and direction of movement are estimated and a device velocity is calculated relative to a prior device velocity via dead-reckoning. The estimated device velocity is corrected for drift and the pedestrian position is calculated based on the corrected estimated current device velocity.

A network of scopes, including one or more lead scopes and one or more follower scopes, is provided to allow scope operators of the respective scopes to track the same presumed target. A lead scope locates a target and communicates target position data of the presumed target to the follower scope. The follower scope uses the target position data and its own position data to electronically generate indicators for use to prompt the operator of the follower scope to make position movements so as to re-position the follower scope from its current target position to move towards the target position defined by the target position data received from the lead scope.

A network of scopes, including one or more lead scopes and one or more follower scopes, is provided to allow scope operators of the respective scopes to track the same presumed target. A lead scope locates a target and communicates target position data of the presumed target to the follower scope. The follower scope uses the target position data and its own position data to electronically generate indicators for use to prompt the operator of the follower scope to make position movements so as to re-position the follower scope from its current target position to move towards the target position defined by the target position data received from the lead scope.

A network of scopes, including one or more lead scopes and one or more follower scopes, is provided to allow the respective scopes to track the same presumed target. A lead scope locates a target and communicates target position data of the presumed target to the follower scope. The follower scope uses the target position data and its own position data to generate electronic control signals for use by follower scope to make position movements so as to re-position the follower scope from its current target position to move towards the target position defined by the target position data received from the lead scope. At least the second scope is mounted to, or integrated into, a vehicle, which uses the target position data to move to a new location so as to allow the second scope to better view the target.

A network of scopes, including one or more lead scopes and one or more follower scopes, is provided to allow the respective scopes to track the same presumed target. A lead scope locates a target and communicates target position data of the presumed target to the follower scope. The follower scope uses the target position data and its own position data to generate electronic control signals for use by follower scope to make position movements so as to re-position the follower scope from its current target position to move towards the target position defined by the target position data received from the lead scope. At least the second scope is mounted to, or integrated into, a vehicle, which uses the target position data to move to a new location so as to allow the second scope to better view the target.

A network of scopes, including one or more lead scopes and one or more follower scopes, is provided to allow scope operators of the respective scopes to track the same presumed target. A lead scope locates a target and communicates target position data of the presumed target to the follower scope. The follower scope uses the target position data and its own position data to electronically generate indicators for use to prompt the operator of the follower scope to make position movements so as to re-position the follower scope from its current target position to move towards the target position defined by the target position data received from the lead scope.

A network of scopes, including one or more lead scopes and one or more follower scopes, is provided to allow scope operators of the respective scopes to track the same presumed target. A lead scope locates a target and communicates target position data of the presumed target to the follower scope. The follower scope uses the target position data and its own position data to electronically generate indicators for use to prompt the operator of the follower scope to make position movements so as to re-position the follower scope from its current target position to move towards the target position defined by the target position data received from the lead scope.