Carl Aslakson monitoring EPI receiver on HYDROGRAPHER.Field testing of EPI - first medium frequency survey navigation system.Invented within the Coast and Geodetic Survey
3/20/2019 10:37:41 AM
Date: August, 1948
Credit: Family of Captain George L. Anderson, C&GS;
Location: Gulf of Mexico
Subject: Charting
Subject: Navigation
Subject: Electronic
Subject: HF and MF Systems