H. L. Jury, Pan American World Airways, Inc., Guided Missile Range Division Patrick Air Force Base, Fla.
The accurate geodetic position of underwater hydrophones and transponders must be knovn to determine the precise location of missile impacts on the Atlantic Missile Range. Accurately located transponders will provide location data for missile guidance and re-eirbry evaluation as well as exact positioning of instrumented ships used for missile, satellite and space vehicle tracking. The geodetic position of many Missile Impact Location System (MILS) hydrophones contains a sizeable error. These hydrophones can be accurately located with shipboard sonar equipment if the ship can be precisely positioned geodetically. Since no other system was available for accurate ship positioning, the Photogrammetric Ocean Survey Equipment (POSE) program was initiated.
Testing of photograrametric ocean survey equipmeirt has been performed at the AMR in cooperation with the U. S. Navy Oceanographic Office. The testing determined with what accuracy a ship could be positioned at sea. A stellar oriented camera on a stable platform was mounted on a roll and pitch motion simulator at Cape Kennedy and later on a ship at sea. This gyro-stabilized camera, with five landbased stellar-oriented cameras, observed an aircraft-borne- strobe light against a stellar background.
Test results were used to compute the geodetic position of the gyro-stabilized camera. It was positioned to 1.22 feet Circular Probable Error (CPE) when mounted on the simulator. Later the ship f s position was established to an accuracy of 2.06 feet CPE. The latter accuracy is comparable to positioning a ship at sea to 300 feet (CPE) while observing a satellite with position uncertainty of plus/ minus 50 "to plus/minus 100 feet at a slant range of 1000 nm. Accuracy of the results greatly exceeded that expected with the equipment used.