DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 ARGOS DOWNLINK Christian Ortega, CLS Bill Woodward, Service Argos

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 SUMMARY Current Argos System Downlink – overview Downlink – overview Downlink Functions/Services Downlink Functions/Services Create a Request to Send a MSG Create a Request to Send a MSG Transmission Modes Transmission Modes PMT - introduction PMT - introduction

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 THE CURRENT ARGOS SYSTEM  Satellite-based data collection and location system  Short message transmission  Unidirectional system  Random access system ( no communication protocol)  Simple, cheap and reliable  But,…

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 …Users cannot communicate with their platform once it is deployed

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 The ARGOS Space segment NOAA 14NOAA 15 NOAA- 16 Argos 1 Argos 2 ADEOS - II Argos 2+ NOAA - 17 Argos 2

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 Evolution of the constellation

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003

HOW ARGOS WORKS NOW  Random transmission ( most of the time)  No acknowledgement if satellite receives a good message Message 1 09:00 Message 2 09:01 Message 3 09:02 Message 4 09:03 lost

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 ARGOS DOWNLINK- Overview Send Short Messages to PMT Equipped Platforms  Send Short Messages to PMT Equipped Platforms Centralized Msg Management - DMMC  Centralized Msg Management - DMMC Global Coverage  Global Coverage

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 Four Main Downlink Functions/Services Downlink Signal/Satellite Detection 1. Downlink Signal/Satellite Detection Global Broadcast of Argos System Related Msgs 2. Global Broadcast of Argos System Related Msgs User Defined Msgs for Remote Control of Platforms 3. User Defined Msgs for Remote Control of Platforms Interactive Data Collection 4. Interactive Data Collection

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 Consequences for users u Transmit more data with acknowledgement of satellite (uplink interactive mode) u Modify setting of parameters inside platforms via the downlink (ex: diving depth for floats, modification of a sampling period on sensors, modification of sensor acquisition strategies, start or stop acquisition,…) u Save energy: possibility to transmit only on satellite passes u The Receiver will be considered as a slave plug and play module like any sensor

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 The receiver detects the satellite signal DOWNLINK MESSAGING SERVICES (1) Signal/Satellite Detection

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 Global Broadcasting of Argos System Messages ( for satellite pass prediction and selection) Argos constellation status UTC time Argos satellite orbital parameters DOWNLINK MESSAGING SERVICES (2) Broadcast service is available to all PMTs!

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 DOWNLINK MESSAGING SERVICES (3) DMMC User or User Office 1) Message reception 2) Acknowledgement message sending MB selection (Japan, France,Sweden, Alaska) MB APC Acknowledgements Directives Remote loading context Requests Sending Messages – Platform Control

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 INTERACTIVE DATA COLLECTION DOWNLINK MESSAGING SERVICES (4)  Satellite Acknowledges Receipt of Error - Free Messages Eliminates Need to Send Repetitive Messages Blindly  Eliminates Need to Send Repetitive Messages Blindly  Significantly Increases Data Throughput During a Satellite Pass  User Must Request This – Not Automatic

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 Interactive Data Collection

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 Create a request to Send a Message To Whom:a PMT / a group of PMTs  To Whom:a PMT / a group of PMTs When:at the earliest date/ at a given date  When:at the earliest date/ at a given date single sending / periodical sending Transmission Mode :triggered / programmed  Transmission Mode :triggered / programmed Transmission period : from 1 satellite pass to 8 days  Transmission period : from 1 satellite pass to 8 days Message type:Predefined / user-defined message  Message type:Predefined / user-defined message

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 Triggered Mode Triggered Mode DMMC Request creation The PMT receives the downlink message and acknowledges Once the satellite receives a message sent by the PMT, it transmits the downlink message PMT is transmittingAPC Acknowledgements MB

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 Programmed Mode Programmed Mode DMMC Request creation The PMT receives the downlink message and acknowledges The satellite sends the downlink message APC Acknowledgements MB

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 Satellite PTTPMT One-wayTwo-way PMT vs PTT

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 PTT Logical Unit Sensors Platform Transmitter Terminal: PTT

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 Receiver PTT Logical Unit Sensors Platform Messaging Transceiver: PMT

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 PMT Development  Bathy Systems, Inc.  Uses Receiver Built by IESM (France)  Prototypes Available in Late 2003  Initial Applications : balloons, drifters, floats

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 Prototype PMT Approx. 6 in Approx. 6 in.

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 BENEFITS OF USING ARGOS 2-WAY

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003  Transmit More Data per Satellite Pass  Modify Parameter Settings on Your Platform  Transmit Only on Satellite Pass – Save Power

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 USING INTERACTIVE MODE  RANDOM ACCESS SYSTEM  No Ground to Sky Protocol  Improve Good Receipt by repeat Xmissions (same msg sent multiple times)  DIFFERENT WITH ARGOS 2-WAY  Error-free msg Receipt is acknowledged  Repeat Transmissions are minimized/eliminated  RESULT = MORE MSGS (DATA per PASS)

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 USING INTERACTIVE MODE FLOAT EXAMPLE – APEX (Webb Research) Current “Typical” Transmission Strategy Current “Typical” Transmission Strategy  4 2/3 Data Triplets (P,T,S) per Argos Msg  15 Msgs are Req’d to Send a Profile of 71 Levels  Each Msg is Sent Multiple Times at a 45 sec. Rep. Rate  Required Surface Time is 3 to 10+Hours

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 USING INTERACTIVE MODE FLOAT EXAMPLE – APEX (continued) Possible Strategy with Argos 2-Way Possible Strategy with Argos 2-Way  4 2/3 Data Triplets (P,T,S) per Argos Msg  15 Msgs are Req’d to Send a Profile of 71 Levels  Each Msg is Sent until ACK is Received  Use a 30 sec. Rep. Rate, Send 20 msgs in a 10 min. Sat. Pass 10 Hours 10 Mins

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 USING INTERACTIVE MODE FLOAT EXAMPLE – APEX (continued)  RESULT: AN ENTIRE PROFILE CAN BE SENT IN A SINGLE SATELLITE PASS!

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003  Parking depth for a float, control of diving cycles, sampling on sensors,...  Modify the transmission strategy (e.g., transmit more data when necessary) USING USER DEFINED MESSAGES REMOTELY MODIFY PLATFORM SETTINGS REMOTELY MODIFY PLATFORM SETTINGS

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 Time (UTC) Thu Sep 25 17:52: (ADEOS II) AOS Thu Sep 25 18:03: in 00:10:52 (00:16:32) Max.El 45 2 ( NOAA 12) AOS Thu Sep 25 22:56: in 05:04:00 (00:14:56) Max.El 20 3 ( NOAA 11) AOS Thu Sep 25 19:16: in 01:23:20 (00:16:38) Max.El 68 4 ( NOAA 14) AOS Fri Sep 26 00:18: in 06:25:53 (00:03:00) Max.El 00 5 ( NOAA 15) AOS Thu Sep 25 23:54: in 06:01:37 (00:06:22) Max.El 01 6 ( NOAA 16) AOS Thu Sep 25 20:02: in 02:09:37 (00:13:56) Max.El 13 7 ( NOAA 17) AOS Thu Sep 25 18:32: in 00:39:05 (00:17:06) Max.El 71 PASS PREDICTION DATA

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, > FFFE2FF23CCB6AA > FFFE2FF23CCB6A59AE > FFFE2FF23CCB6A58A > FFFE2FF23CCB6AA > FFFE2FF23CCB6A5AB > FFFE2FF23CCB6AAA > FFFE2FF23CCB6AAB5E > FFFE2FF23CCB6A5BB > FFFE2FF23CCB6A5E9F > FFFE2FF23CCB6AAE > FFFE2FF23CCB6AAF720A > FFFE2FF23CCB6A5F940B > FFFE2FF23CCB6AAD640C > FFFE2FF23CCB6A5D820D > FFFE2FF23CCB6A5C890E > FFFE2FF23CCB6AAC6F0F > FFFE2FF23CCB6A56C > FFFE2FF23CCB6A1A D0A0D0AFFFFFFFFFFFFFFFFFF 17 DEMO MESSAGES SENT

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 PMT> Thu Sep 25 18:03: Satellite: 1 (ADEOS II) is overhead Duration: 00:16:32 Max. El: 45 Sending Request for Interactive RECEIVED: 23CCB6A ABCDEFF67D *Interactive Request timed out Sending Request for Interactive *Interactive Request timed out Sending Request for Interactive RECEIVED: 23CCB6A102AE8D01570B *Interactive Session Go-Ahead Message BEGIN INTERACTIVE SESSION

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 Send Message IRP 00 -> FFFE2FF23CCB6AA RECEIVED: 23CCB6A101A94825C4 Acknowledgement of an Interactive PMT uplink message within a session. ACK on Message £0 Send Message IRP 01 -> FFFE2FF23CCB6A59AE Send Message IRP 02 -> FFFE2FF23CCB6A58A RECEIVED: 23CCB6A10158A529B7 Acknowledgement of an Interactive PMT uplink message within a session. ACK on Message £2 Send Message IRP 03 -> FFFE2FF23CCB6AA Send Message IRP 04 -> FFFE2FF23CCB6A5AB RECEIVED: 23CCB6A1015AB33D22 Acknowledgement of an Interactive PMT uplink message within a session. ACK on Message £4 Send Message IRP 05 -> FFFE2FF23CCB6AAA RECEIVED: 23CCB6A101AA55B30B Acknowledgement of an Interactive PMT uplink message within a session. ACK on Message £5 Send Message IRP 06 -> FFFE2FF23CCB6AAB5E RECEIVED: 23CCB6A101AB5E3151 Acknowledgement of an Interactive PMT uplink message within a session. ACK on Message £6 Send Message IRP 07 -> FFFE2FF23CCB6A5BB Send Message IRP 08 -> FFFE2FF23CCB6A5E9F RECEIVED: 23CCB6A1015E9F1408 Acknowledgement of an Interactive PMT uplink message within a session. ACK on Message £8

DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003 PMT> PMT>stats Bytes Sent : 504 Bytes in Message: 504 Percent Complete: 100 SUMMARY OF SESSION