ARGOS DOWNLINK
Christian Ortega, CLS
Bill Woodward, Service Argos
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-14
NOAA-15
NOAA-12
NOAA 14
Argos 1
Argos 1
NOAA-11
Argos 1
Argos 1
Argos 1
NOAA-16
NOAA-17
NOAA 15
Argos 2
NOAA
- 16
Argos 2
- 2 17
NOAA
Argos
ADEOS-II
Argos 2
Argos 2
Argos 2
ADEOS Argos
II 2+
Argos 1
Argos 2+
DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003
Evolution of the constellation
Year
Sat Model
2002
Argos II
+
2005 Argos III
2013 Argos IV
Uplink
Sat Sensitivity
(bits/sec.)
400
5 000
- 131 dBm
- 137 dBm
Reception
bandwidth
Downlink
(bits/sec.)
80 KHz
200
110 KHz
TBD
DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003
400
00
01
02
03
04
05
06
07
08
09
10
11
12
Local Equatorial Crossing Time
0530
13
14
15
16
17
NPOESS
C3
(A4)
18
C6
(A3) ?
0930
17
NOAA
NPOESS
C4
C1
M1
METOP
(A3)
M2
NPOESS
M3
(A3) ?
(A3)
(ADEOS 2)
1330
NOAA
(A3)
N’
N
16
POES
(A3)
METOP
C2
NPOESS
NPOESS
DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003
C5
ARGOS DOWNLINK- Overview
 Send Short Messages to PMT Equipped
Platforms
 Centralized Msg Management - DMMC
 Global Coverage
DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003
Consequences for users

Transmit more data with acknowledgement of satellite
(uplink interactive mode)

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,…)

Save energy: possibility to transmit only on satellite
passes

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
Platform Messaging Transceiver: PMT
Receiver
PTT
Logical
Unit
Sensors
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.
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
 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
 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
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
USING USER DEFINED MESSAGES
 REMOTELY MODIFY PLATFORM
SETTINGS
 Parking depth for a float, control of
diving cycles, sampling on sensors,...
 Modify the transmission strategy (e.g.,
transmit more data when necessary)
DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003
PASS PREDICTION DATA
Time (UTC) Thu Sep 25 17:52:57 2003
1 (ADEOS II) AOS Thu Sep 25 18:03:49 2003 in 00:10:52 (00:16:32) Max.El 45
2 ( NOAA 12) AOS Thu Sep 25 22:56:57 2003 in 05:04:00 (00:14:56) Max.El 20
3 ( NOAA 11) AOS Thu Sep 25 19:16:17 2003 in 01:23:20 (00:16:38) Max.El 68
4 ( NOAA 14) AOS Fri Sep 26 00:18:50 2003 in 06:25:53 (00:03:00) Max.El 00
5 ( NOAA 15) AOS Thu Sep 25 23:54:34 2003 in 06:01:37 (00:06:22) Max.El 01
6 ( NOAA 16) AOS Thu Sep 25 20:02:34 2003 in 02:09:37 (00:13:56) Max.El 13
7 ( NOAA 17) AOS Thu Sep 25 18:32:02 2003 in 00:39:05 (00:17:06) Max.El 71
DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003
17 DEMO MESSAGES SENT
00 00 -> FFFE2FF23CCB6AA9480032323232323232323232323232323232323232323232323232323232
01 00 -> FFFE2FF23CCB6A59AE0132323232323232323232323232323232323232323232323232323232
02 00 -> FFFE2FF23CCB6A58A50232323232323232323232323232323232323232323232323232323232
03 00 -> FFFE2FF23CCB6AA8430332323232323232323232323232323232323232323232323232323232
04 00 -> FFFE2FF23CCB6A5AB30432323232323232323232323232323232323232323232323232323232
05 00 -> FFFE2FF23CCB6AAA550532323232323232323232323232323232323232323232323232323232
06 00 -> FFFE2FF23CCB6AAB5E0632323232323232323232323232323232323232323232323232323232
07 00 -> FFFE2FF23CCB6A5BB80732323232323232323232323232323232323232323232323232323232
08 00 -> FFFE2FF23CCB6A5E9F0832323232323232323232323232323232323232323232323232323232
09 00 -> FFFE2FF23CCB6AAE790932323232323232323232323232323232323232323232323232323232
10 00 -> FFFE2FF23CCB6AAF720A32323232323232323232323232323232323232323232323232323232
11 00 -> FFFE2FF23CCB6A5F940B32323232323232323232323232323232323232323232323232323232
12 00 -> FFFE2FF23CCB6AAD640C32323232323232323232323232323232323232323232323232323232
13 00 -> FFFE2FF23CCB6A5D820D32323232323232323232323232323232323232323232323232323232
14 00 -> FFFE2FF23CCB6A5C890E32323232323232323232323232323232323232323232323232323232
15 00 -> FFFE2FF23CCB6AAC6F0F32323232323232323232323232323232323232323232323232323232
16 00 -> FFFE2FF23CCB6A56C71032323232323232323232323232323232323232323232323232323232
17 00 -> FFFE2FF23CCB6A1A62913232323232323232323232323232320D0A0D0AFFFFFFFFFFFFFFFFFF
DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003
BEGIN INTERACTIVE SESSION
PMT>
Thu Sep 25 18:03:51 2003
Satellite: 1 (ADEOS II) is overhead
Duration: 00:16:32
Max. El: 45
Sending Request for Interactive
RECEIVED: 23CCB6A104000123456789ABCDEFF67D
*Interactive Request timed out
Sending Request for Interactive
*Interactive Request timed out
Sending Request for Interactive
RECEIVED: 23CCB6A102AE8D01570B
*Interactive Session Go-Ahead Message
DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003
Send Message IRP 00 -> FFFE2FF23CCB6AA9480032323232323232323232323232323232323232323232323232323232
RECEIVED: 23CCB6A101A94825C4
Acknowledgement of an Interactive PMT uplink message within a session.
ACK on Message £0
Send Message IRP 01 -> FFFE2FF23CCB6A59AE0132323232323232323232323232323232323232323232323232323232
Send Message IRP 02 -> FFFE2FF23CCB6A58A50232323232323232323232323232323232323232323232323232323232
RECEIVED: 23CCB6A10158A529B7
Acknowledgement of an Interactive PMT uplink message within a session.
ACK on Message £2
Send Message IRP 03 -> FFFE2FF23CCB6AA8430332323232323232323232323232323232323232323232323232323232
Send Message IRP 04 -> FFFE2FF23CCB6A5AB30432323232323232323232323232323232323232323232323232323232
RECEIVED: 23CCB6A1015AB33D22
Acknowledgement of an Interactive PMT uplink message within a session.
ACK on Message £4
Send Message IRP 05 -> FFFE2FF23CCB6AAA550532323232323232323232323232323232323232323232323232323232
RECEIVED: 23CCB6A101AA55B30B
Acknowledgement of an Interactive PMT uplink message within a session.
ACK on Message £5
Send Message IRP 06 -> FFFE2FF23CCB6AAB5E0632323232323232323232323232323232323232323232323232323232
RECEIVED: 23CCB6A101AB5E3151
Acknowledgement of an Interactive PMT uplink message within a session.
ACK on Message £6
Send Message IRP 07 -> FFFE2FF23CCB6A5BB80732323232323232323232323232323232323232323232323232323232
Send Message IRP 08 -> FFFE2FF23CCB6A5E9F0832323232323232323232323232323232323232323232323232323232
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
SUMMARY OF SESSION
PMT>
PMT>stats
Bytes Sent : 504
Bytes in Message: 504
Percent Complete: 100
DBCP Technical Workshop – Angra dos Reis, Brazil – October 20, 2003