Abstract: Methods of calibrating strapdown heading sensors and strapdown heading sensors are provided. The methods include compensating raw sensor data generated by sensors of an uncalibrated strapdown heading sensor to compensate for errors in an instrument frame of the strapdown heading sensor. The strapdown heading sensor is put in a target apparatus and output data is compensated to compensate for errors in an apparatus frame relative to the instrument frame. The strapdown heading sensors include a housing and a compass module having a first sensor configured to detect a magnetic field of the Earth and a second sensor configured to detect a gravitational force of the Earth. The first sensor and the second sensor are each passively isolated from bending and/or flexing of the housing such that an alignment between the first sensor and the second sensor is not disturbed due to the bending and/or flexing.

Abstract: Methods of calibrating strapdown heading sensors and strapdown heading sensors are provided. The methods include compensating raw sensor data generated by sensors of an uncalibrated strapdown heading sensor to compensate for errors in an instrument frame of the strapdown heading sensor. The strapdown heading sensor is put in a target apparatus and output data is compensated to compensate for errors in an apparatus frame relative to the instrument frame. The strapdown heading sensors include a housing and a compass module having a first sensor configured to detect a magnetic field of the Earth and a second sensor configured to detect a gravitational force of the Earth. The first sensor and the second sensor are each passively isolated from bending and/or flexing of the housing such that an alignment between the first sensor and the second sensor is not disturbed due to the bending and/or flexing.

Abstract: Methods of calibrating strapdown heading sensors and strapdown heading sensors are provided. The methods include compensating raw sensor data generated by sensors of an uncalibrated strapdown heading sensor to compensate for errors in an instrument frame of the strapdown heading sensor. The strapdown heading sensor is put in a target apparatus and output data is compensated to compensate for errors in an apparatus frame relative to the instrument frame. The strapdown heading sensors include a housing and a compass module having a first sensor configured to detect a magnetic field of the Earth and a second sensor configured to detect a gravitational force of the Earth. The first sensor and the second sensor are each passively isolated from bending and/or flexing of the housing such that an alignment between the first sensor and the second sensor is not disturbed due to the bending and/or flexing.

Abstract: Methods of calibrating strapdown heading sensors and strapdown heading sensors are provided. The methods include compensating raw sensor data generated by sensors of an uncalibrated strapdown heading sensor to compensate for errors in an instrument frame of the strapdown heading sensor. The strapdown heading sensor is put in a target apparatus and output data is compensated to compensate for errors in an apparatus frame relative to the instrument frame. The strapdown heading sensors include a housing and a compass module having a first sensor configured to detect a magnetic field of the Earth and a second sensor configured to detect a gravitational force of the Earth. The first sensor and the second sensor are each passively isolated from bending and/or flexing of the housing such that an alignment between the first sensor and the second sensor is not disturbed due to the bending and/or flexing.

Abstract: A strapdown heading sensor includes an elongated housing and a compass module at least partially positioned within an inner cavity of the elongated housing. The compass module is cantilevered within the inner cavity of the elongated housing.

Abstract: A strapdown heading sensor includes an elongated housing and a compass module at least partially positioned within an inner cavity of the elongated housing. The compass module is cantilevered within the inner cavity of the elongated housing.

Abstract: A strapdown heading sensor includes an elongated housing and a compass module at least partially positioned within an inner cavity of the elongated housing. The compass module is cantilevered within the inner cavity of the elongated housing.

Abstract: Method and apparatus for creating discrete phase optical elements. An arbitrary phase structure is represented by color encoding to produce a color encoded mask. Thereafter, a photo-sensitive substrate is exposed to broad spectrum light transmitted through or reflected from the mask to create the discrete phase structure in the substrate. In preferred embodiments, the exposed substrate is developed and bleached (if necessary) to remove pigmentation to produce highly efficient multiple level phase structures for optical applications. The color encoded mask is produced by a computer-driven color printer resulting in very fast turnaround times.

Abstract: A write-once-read-once batteryless token stores access data using fuses similar to those found in programmable fuse link devices. These fuses indicate the status of a particular bit in either of two memory arrays. An intact fuse indicates that a bit is a logical zero, and a blown fuse indicates that a bit is a logical one. The process of reading a particular bit in either array causes the destruction of the corresponding memory cells in both arrays before the data from the selected cell becomes available to the reading device. The memory bit cells are destroyed by blowing the bit fuse during the read cycle.