DBCP 22 Workshop LaJolla October 2006 ARGOS PERFORMANCE IN THE EUROPEAN REGION Bill Woodward, Philippe Gros, Christian Ortega CLS

DBCP 22 Workshop LaJolla October 2006 THE “PROBLEM”  ARGOS USERS REPORT REDUCTION IN NUMBER OF MESSAGES RECEIVED  IMPACT IS A FUNCTION OF XMITTED POWER LEVEL  SOME “LOW POWER” PTTs MAY NOT BE HEARD IN CERTAIN REGIONS  ARGO FLOAT “TE” IS REDUCED

DBCP 22 Workshop LaJolla October 2006 THE RESPONSE  SYSTEMATIC INVESTIGATION BY CLS & CNES  TWO INITIAL OBJECTIVES: Estimating the Mean Noise Level Seeking Locations of Discrete Noise Sources

DBCP 22 Workshop LaJolla October 2006 THE APPROACH  TECHNICAL SATELLITE-BASED MEASUREMENTS CLOSE CO-OP w/USERs & MANUFACTURERS CLOSE CO-OP w/USERs & MANUFACTURERS ANALYTICAL TOOLS TO ASSIST USERS TO OPTIMIZE THEIR XMIT STRATEGY ANALYTICAL TOOLS TO ASSIST USERS TO OPTIMIZE THEIR XMIT STRATEGY  ADMINISTRATIVE INFORMAL & FORMAL REQUESTS BY CNES TO GOVERNMENTS INFORMAL & FORMAL REQUESTS BY CNES TO GOVERNMENTS

DBCP 22 Workshop LaJolla October 2006 WHERE WE ARE  SYSTEM OCCUPANCY

DBCP 22 Workshop LaJolla October 2006  NOISE MEASURED BY DORIS: MHz

DBCP 22 Workshop LaJolla October 2006  PSEUDO-MESSAGING PROCESSING

DBCP 22 Workshop LaJolla October 2006 DISCRETE ARGOS INTERFERENCE SOURCES HAVE BEEN LOCATED IN THE FOLLOWING COUNTRIES: DISCRETE ARGOS INTERFERENCE SOURCES HAVE BEEN LOCATED IN THE FOLLOWING COUNTRIES: AlbaniaAlgeria ItalySyria Ecuador (2)Russia (2) INFORMAL REQUESTS HAVE BEEN SENT REQUESTING ELIMINATION OF THIS INTERFERENCE INFORMAL REQUESTS HAVE BEEN SENT REQUESTING ELIMINATION OF THIS INTERFERENCE

DBCP 22 Workshop LaJolla October 2006  MINIMUM RECEIVED POWER LEVEL

DBCP 22 Workshop LaJolla October 2006 IMPACT OF THE NOISE FLOOR IMPACT OF THE NOISE FLOOR

DBCP 22 Workshop LaJolla October 2006 PRELIMINARY CONCLUSIONS: Beacons less than 250 mW may not be received Beacons less than 250 mW may not be received Beacons more than 500 mW have higher probability of reception Beacons more than 500 mW have higher probability of reception

DBCP 22 Workshop LaJolla October 2006 NOW WHAT?  CONTINUE TO MEASURE NOISE LEVELS  IMPLEMENT GROUND BASED MEASUREMENTS TO LOCATE SOURCES OF WIDE-BAND NOISE  MAINTAIN PRESSURE ON COUNTRIES WITH DISCRETE INTERFERENCE SOURCES