Target locator device and methods

A method for determining a target location, the method comprising:

• determining an alignment heading for a target locating device using a high performance gyroscope with the target locator device placed in an alignment position;
• estimating a level attitude of the target locating device when the target locator device is placed in the alignment position;
• calibrating a triad of gyroscopes and accelerometers based on the level attitude and the alignment heading;
• estimating a heading and an elevation of the target locator device using the triad of gyroscopes when the target locator device is aimed at a target;
• determining a position of the target locator device with a GNSS receiver, when the target locator device is aimed at a target;
• determining a range distance to the target, when the target locator device is aimed at a target;
• and
• calculating a position of the target based on the position of the target locator device, the range distance to the target, and the heading and the elevation of the target locator device.

A target locator device, the device comprising:

• a handheld housing having a target locating sight scope and a rangefinder;
• an inertial measurement unit including an accelerometer triad and a gyroscope triad;
• a high performance gyroscope located within the housing;
• a global navigation satellite system (GNSS) receiver;
• and
• a processor coupled to the high performance gyroscope, the inertial measurement unit, the rangefinder and the GNSS receiver;
• wherein the processor calculates a position of a target based on a position of the target locator device as determined by the GNSS receiver, a range to the target as determined by the rangefinder, and a heading and elevation measurement to the target as determined from the inertial measurement unit;
• wherein the inertial measurement unit is calibrated to an alignment heading determined from Earth rotation as measured by the high performance gyroscope.