A revised control network for Mercury

An improved control net for Mercury has been completed by utilizing images acquired during the three Mariner 10 flybys in 1974-1975. Relative position al errors within the net are similar to 1 km on average, and absolute locat ions are estimated to be better than 25 km. The analytical triangulation re sulted in new values for focal lengths (Camera A: 1493.6 mm; Camera B: 1500 .1 mm), W-0 (329.548 degrees), and camera orientation angles for 811 images acquired during all three flybys of Mercury.