Remote GTS Technical File Access

Remote GTS Technical FileAccess via Email

Argos GTS users can access (read or write) technical files of GTS platformsvia Internet Email. The system reads received messages on an hourly basis,process the messages and reply to the users.
Table of contents:

Read access
Write access
Security issues
Managing historical records
Updates between centers
Information to provide to the Argos User Office

Annex 1, SHORT format
Annex 2, LONG format
GTSMOD language

Read Access

Technical file access request is done via Email according to the following rules:

User provides the User Office with Email address he will use to send messages. This address is inserted into a list updated by the User Office. This list permits to check identity of the user and to send results back to him.
User sends one message per platform for which he wants to read GTS Technical File.
Based upon what center does the platform belong to, the message is being sent to an Internet address in SAI or CLS:
Toulouse: gts_tf@diane.cls.fr
Landover: gts_tf@argosinc.com
Subject line follows the syntax below:

SHORT format: TF:READ;USER=Username; PTT=Argos_ID

LONG format: TF:READ;USER=Username; PTT=Argos_ID;FORMAT=LONG

As seen above, FORMAT keyword is optional. Its default value is SHORT (see Annex 1 for SHORT and Annex2 for LONG formats).

Text of the message is free. It will not be processed by the system but will be archived.

The system recognizes the Username and the Internet origin of the message. It checks that the two match via the list of Email addresses maintained by the User Office. If they don’t the message is ignored and no error messages sent back to the user. If they do match, Technical File data are read and returned to the user in less than 1 hour to the address given to the User Office. If an error occurs (e.g. syntax error in the subject line, or inexistent PTT numbers, or unauthorized access) then an error messages returned to the originator.

Write Access

Write access follows similar rules as above except for the following ones. Writing unit is still the platform.

User send a message per platform for which he wants to modify the GTS Technical File.
Subject line follows the syntax below:

TF:WRITE;USER=Username

Message text includes instructions for modification of a platform Technical File according to the GTSMOD language. Hence a user will be able to re-use a reading file (FORMAT=LONG), to modify it and to submit it via Email.

The system recognizes the Username and the Internet origin of the message. It checks that the two match via the list of Email addresses maintained by the User Office. If they don’t the message is ignored and no error messages sent back to the user. If they do match, Technical File data are modified and confirmation returned to the user in less than 1 hour to the address given to the User Office. If an error occurs (e.g. syntax error in the GTSMOD text submitted, or inexistent PTT numbers, or unauthorized access) then an error message is returned to the originator.

User must know that the operational system will not be able to take the modification into account before a delay of 1 minute to one hour.

Security Issues

Authentication

Authentication is being done thanks to the Email address of line" From:" of message being sent. A dedicated Table called PGC within the GTS data base permits to manage these addresses.

Authorization

For a given Argos Program, the Principal GTS Coordinator (PGC) is the only person allowed by the Argos program manager to make modifications to GTS technical files (manually via the User Office and remotely). However, a program manager is not obliged to designate a PGC. In this case, only the program manager himself plus authorized users will be in a position to do so. Users can be authorized to access to all program of a given program manager, or to one or more program, or to one or more platforms of the program manager. Above aspects of security are already taken into account in the GTS subsystem.

Access restriction

If a user has reservations regarding the level of security offered, he can ask that all of his platforms of all of his program be removed from remote access. For a program, he can also forbid remote access or limit it to read access only. By default, remote reading as well as writing access is forbidden. A user will therefore have to explicitly ask for read or read/write access for each of his program if he wants to do so.

Managing historical records

A user is responsible for remote modifications of his GTS Technical Files. An historical record of all remote modification is being automatically managed in order to solve possible problems.

Remote Technical File access messages and replies sent back to the users are automatically being archived by the VAX Email system. Copies of replies to the users are automatically copied to the User Office (e.g. Useroffice@argosinc.com).In addition, information "Argos ID" + "Username" (i.e. the one who asks for the modification) + "Date of modification" is automatically being kept in the GTS data base. It is therefore easy to find when a user made modifications to a platform, and what modifications he did.

Updates between centers

Updates between centers are done automatically using standard GTS products.

Information to provide to the User Office

If a user wants to remotely access to his GTS Technical Files, he must:

For each of his program, provide the User Office with either the name of the PGC who will be authorized to access technical file data remotely, or with the list of users who will have authorization.
For each program, for the designated PGC or for each authorized user, provide the User Office with the Email address he will use to access the system. The User Office will then provide the user with User Names for the PGC or authorized users.
For each program ask for read or read/write access.

Annex 1: SHORT Format in read access

Example:

GTS Technical file information for an Argos platform (SHORT)

PTT:18646 WMO=73502    GTS=N Program:01155 User:MORRISSY     DROGUE=N
CODE BUOY,  Bulletin Header = SSVX03

## SENSOR NAME      KIND       G LEVEL    A        B        PR POS BIT RF OFFST
01 HOUR             TIME
02 SEATEMP          WT_T       Y 0.00     1.000    0.000    B1  16 10   8     0
03 ATMPRES          AI_P       Y 1.00     1.000    0.000    B1   0 11   4     0
04 BATTERY          DEFAULT    Y 0.00     1.000    0.000    B1  26  6   4     0
05 AIRTEMP          AI_T       Y 0.00     1.000    0.000    B1  32 10   4     0
06 TENDCHAR         AI_PTC     Y 0.00     1.000    0.000    B1  42  6  11     0
07 TEND             AI_PT      Y 0.00     1.000    0.000    B1  48  8   4     0
08 HOUR_H-1         TIME
09 SEATEMP_H-1      WT_T       Y -1.00    1.000    0.000    B1  72 10   4   -60
10 ATMPRES_H-1      AI_P       Y 0.00     1.000    0.000    B1  56 11   4   -60
11 BATTERY_H-1      DEFAULT    Y 0.00     1.000    0.000    B1  82  6   4   -60
12 AIRTEMP_H-1      AI_T       Y 0.00     1.000    0.000    B1  88 10   4   -60
13 TENDCHAR_H-1     AI_PTC     Y 0.00     1.000    0.000    B1 104  6  11     0
14 TEND_H-1         AI_PT      Y 0.00     1.000    0.000    B1 104  8   4   -60
15 HOUR_H-2         TIME
16 ATMPRES_H-2      AI_P       Y 0.00     1.000    0.000    B1 112 11   4  -120
17 SEATEMP_H-2      WT_T       Y 0.00     1.000    0.000    B1 128 10   4  -120
18 BATTERY_H-2      DEFAULT    Y 0.00     1.000    0.000    B1 138  6   4  -120
19 AIRTEMP_H-2      AI_T       Y 0.00     1.000    0.000    B1 144 10   4  -120
20 TENDCHAR_H-2     AI_PTC     Y 0.00     1.000    0.000    B1 154  6  11     0
21 TEND_H-2         AI_PT      Y 0.00     1.000    0.000    B1 160  8   4  -120
22 HOUR_H-3         TIME
23 ATMPRES_H-3      AI_P       Y 0.00     1.000    0.000    B1 168 11   4  -180
24 SEATEMP_H-3      WT_T       Y 0.00     1.000    0.000    B1 184 10   4  -180
25 BATTERY_H-3      DEFAULT    Y 0.00     1.000    0.000    B1 194  6   4  -180
26 AIRTEMP_H-3      AI_T       Y 0.00     1.000    0.000    B1 200 10   4  -180
27 TENDCHAR_H-3     AI_PTC     Y 0.00     1.000    0.000    B1 210  6  11     0
28 TEND_H-3         AI_PT      Y 0.00     1.000    0.000    B1 216  8   4  -180

Columns:##           Sensor order in the declaration

SENSOR NAME  Sensor name
KIND         Type of geo-physical measurement G            
GTS distribution on/off for the sensor
LEVEL        Height/Depth of probe
A            Coefficient A for linear correction (Y=A*Y+B)
B            Coefficient B for linear correction (Y=A*Y+B)
PR           Processing type for the calibration curve
POS          Bit position in the Argos message (first message bit = 0)
BIT          Number of bits in the Argos message
RF           Reference time used for computation of observation time
OFFST        Time offset for computation of observation time

Annex 2: LONG format (compatible with GTSMOD)

Example:

This program is to read calibration information from the GTS
Data Base for a given PTT and  to convert  this  information
into  a  file  using  the CALIBRATION compiler instructions.

PTT:22121
WMO=55574
! Program=00476 User=HICKMAN
GTS=Y
DROGUE=N
DEPLOYMENT= -36.000, 161.200
ALTITUDE=          0
! CODE BUOY Header code =SSVX    Header PTT=03

SENSOR  ATMPRES   
   ! Sensor kind:AI_P   
   DISSEM=Y   
   LEVEL= 0.0000000000E+00   
   TIME_OFFSET=          0   
   ! Linear Correction: a= 0.1000000000E+01, b= 0.0000000000E+00   
   LIMITS= 0.9010000000E+03, 0.1050000000E+04   
   CALIBRATION_TYPE B1         
         0: 0.9000000000E+03      
      1023: 0.1053449951E+04

SENSOR  SEATEMP   
   ! Sensor kind:WT_T   
   DISSEM=Y   
   LEVEL= 0.0000000000E+00   
   TIME_OFFSET=          0   
   ! Linear Correction: a= 0.1000000000E+01, b= 0.0000000000E+00   
   LIMITS=-0.3000000000E+01, 0.3490000153E+02   
   CALIBRATION_TYPE B1         
         0:-0.3250000000E+01       
       255: 0.3500000000E+02

SENSOR  ATMPRES_H-1  
   ! Sensor kind:AI_P   
   DISSEM=Y   
   LEVEL= 0.0000000000E+00   
   TIME_OFFSET=          0   
   ! Linear Correction: a= 0.1000000000E+01, b= 0.0000000000E+00   
   LIMITS= 0.9010000000E+03, 0.1050000000E+04   
   CALIBRATION_TYPE B1         
         0: 0.9000000000E+03      
      1023: 0.1053449951E+04