SELF LOCATING, EXPENDABLE, AIR-DEPLOYABLE COAST GUARD SURFACE DRIFTER ("SEACS") BUOY

IN ORDER TO PLAN AN EFFECTIVE SEARCH, COAST GUARD PLANNERS NEED TO COLLECT TRUE SURFACE CURRENT AND OCEANOGRAPHIC DATA,GET THAT DATA TO THE SEARCH PLANNERS IN A TIMELY FASHION, AND PROVIDE THE CURRENT SEARCH PLAN TO THE OPERATIONAL SEARCH ELEMENTS. DERIVED FROM THE STANDARD CODE DRIFTER, THE SELF-LOCATING EXPENDABLE, AIR DEPLOYABLE COAST GUARD SURFACE DRIFTER ("SEACS") BUOY WILL PROVIDE WORLDWIDE COVERAGE OF LAGRANGIAN DRIFTING WITH POSITION AND DATA REPORTING UPON REQUEST OR AUTOMATICALLY EVERY 30 MINUTES FOR45 DAYS. BY EXPLOITING RECENT DEVELOPMENTS IN SATELLITE COMMUNICATIONS AND NAVIGATION, THE SEACS COULD BECOME OPERATIONAL IN 1993 PROVIDING AN ACCURACY OF ABOUT 30 METERSFOR BUOYS ESTIMATED TO COST $1,000. AN ACCURACY OF ABOUT 10METERS COULD BE PROVIDED FOR BUOYS ESTIMATED TO COST ABOUT $2,000. THE LESS EXPENSIVE CAPABILITY IS ACHIEVED BY UTILIZING THE ORBCOMM SMALL SATELLITE SYSTEM AND A NOVEL RECEIVER DESIGN TO PROVIDE TWO-WAY COMMUNICATIONS AND DOPPLER-DERIVED NAVIGATION. THE MORE ACCURATE CAPABILITY ISOBTAINED BY ADDING A GPS ANTENNA AND RECEIVER AT THE EXPENSEOF GREATER MASS AND A HIGHER POWER REQUIREMENT. THE SAME BASIC SATELLITE COMMUNICATIONS CAPABILITY COULD BE USED TO SEND REVISED SEARCH PLANS TO ENROUTE SAR AIRCRAFT.