Abstract: A system which derives the attitude of a body as it rotates and travels through the earth's magnetic field. At least one magnetometer is placed in the body and provides an output signal during flight of the body. The zero crossings of the output signal are used to formulate a time discriminant. This time discriminant is compared with a roll angle discriminant for which a value of attitude has been previously determined. From the comparison, the attitude during flight may be determined. A time discriminant can also be formulated using two magnetometers.

Abstract: A system which derives the attitude of a body as it rotates and travels through the earth's magnetic field. At least one magnetometer is placed in the body and provides an output signal during flight of the body. The zero crossings of the output signal are used to formulate a time discriminant. This time discriminant is compared with a roll angle discriminant for which a value of attitude has been previously determined. From the comparison, the attitude during flight may be determined. A time discriminant can also be formulated using two magnetometers.

Abstract: A method to determine the direction in which a spinning projectile is traveling. A solar sensor array on the projectile is used to calculate the orientation of the axis of rotation of the projectile with respect to a known solar field and a magnetometer sensor array is used to calculate the orientation of the axis of rotation of the projectile with respect to a known magnetic field, both fields being represented by respective vectors having magnitude and direction. With the known and calculated orientations, the pointing direction may be obtained by vector combination.

Abstract: A system which is packaged within a projectile fuze body and obtains data relative to the projectile during a launch. Sensors are provided which obtain in-bore data as well as in-flight data. The in-bore data is recorded at a fast rate during in-bore travel of the projectile and is read out, continuously, at a slower rate during in-flight travel. Both in-bore data and in-flight data are encoded and transmitted to a ground station for analysis.

Abstract: An optical alignment device having a sensor housing with obstructing geomy which restricts the amount of sunlight that enters the sensor and impinges upon a photoelectric cell within the sensor body. The restriction of light properly maintains a constant area of illumination of the photoelectric cell over a wide range of incident angles about the insensitive axis. Variations in incident angle about the sensitive axis produces a significant change in illumination area for small changes in the incident angle. Thus, the device produces a significant change in output with respect to alignment with its sensitive axis and an invariant output with respect to alignment to its insensitive axis.