Brian, Craig et al,
With regards to the positional data format, from what I remember this
just seems to be a slight editorial mistake, and we had agreed for both
of the fields to be in the format required.
For the time stamp, this point was raised for you Brian and from what I
can remember the discussion came out with the following results:
1. After discussions with the IMO Technical Representative at the
meting (Vijayan, please correct me if I get any of this wrong), it was
felt that if the equipment did not transmit the seconds element of the
time stamp this would then be defaulted to "00" (zero zero) in the XML
format and this would be acceptable.
2. It was decided to keep this in order to be able to be able to allow
an element of future proofing into the system, as we have no knowledge
of what information future equipment will transmit
it was felt that it would be easier, at this stage, to incorporate a
seconds element into the time stamp rather than try to alter an already
live system at a future date.
3. It was also felt that it would be best to keep the seconds element
in the positional message time stamps to allow continuity across the
entire LRIT system, as within the other time stamp elements in the
system a higher level of accuracy is required. Again, if an XML expert
can provide more information, it was felt the if this information was
not transmitted then it could be defaulted to "00".
From my memory these were the salient pints that had been raised, but
if anybody wishes further discussion or clarification on this please
don't hesitate to contact me.
Regards,
Guy
Guy Sear
E-Navigation Projects Manager
Maritime and Coastguard Agency
United Kingdom
Tel : + 44 (0) 2380 329 431
Mobile : +44 (0) 7710 877 840
Fax : +44 (0) 2380 329 290
Email: Guy.Sear(a)mcga.gov.uk
>> Brian_Mullan(a)inmarsat.com 01/06/2007 09:48:15 >>>
Hi, Hayley
Many thanks for your email. I can agree that the text of the document
is
clear; but that the wording in the table is not consistent and appears
even to contradict the text you quote. My copy of the document shows
wording for 1.1.1.1 that is different:
"The intent of this document is to outline the technical
specifications
for communication within the international Long-Range Identification
and
Tracking (LRIT) system as stated in the terms of reference of
resolution
MSC.211(81)."
Your reference is new text in 2.2.2.4 in the copy that I received
(15-02-2007 LRIT ad hoc WG)
In Table 2, the heading indicates "Parameter provided by LRIT
Shipborne
Equipment" and then describes the various elements, including
specifying
the format. It is clear to me and others that this method of
presenting
the information in the table means that the information transmitted by
the shipborne equipment *must* follow the format written in the table.
This is where the difficulty lies - the wording is over-prescriptive
and
does not accord with the wording in 2.2.2.4. My original email showed
how, in Inmarsat C position reporting at least, the way the
information
is transmitted. Other shipborne systems probably will have their own
format for presenting data to the ASP.
May I suggest, please, that we stick to requiring that the specific
data
elements (unique identifier, latitude/longitude and date/time of the
position) are transmitted from the ship and then only start to
prescribe
the format for onward transmission from the ASP? In other words, as
long
as the shipborne equipment transmits, as a minimum, the required
elements, any format is acceptable. This allows for all approved
shipborne LRIT systems to be offered, no matter in which order or
format
the data is presented. This approach will also allow the table to be
in
accord with the new wording in 2.2.2.4
I hope that this is clear. Your hard work is very much appreciated and
it is clearly understood that the document remains a "work in
progress".
Please don't take my input as criticism - it is not! All I seek is
clarity of the wording for all.
With best wishes
Brian
Brian Mullan
Head, Maritime Safety Services
Inmarsat, 99 City Road, London EC1Y 1AX, UK
Tel: +44 (0)20 7728 1464
Fax: +44 (0)20 7728 1689
Mob: +44 (0)7711 495836
www.inmarsat.com
________________________________
From: Hayley, Craig [mailto:HayleyCR@DFO-MPO.GC.CA]
Sent: 31 May 2007 19:05
To: ccglrit-gcclrit(a)lists.ncf.ca
Cc: Brian Mullan
Subject: RE: [Ccglrit-gcclrit] June 12-14 meeting of the Ad hoc
Working
Group onEngineering Aspects of LRIT, Hamburg Germany
Hi Brian,
Thanks for the e-mail. I hope more people will take the time to read
the
documents and provide comments. I assume you are referring to the LRIT
communication document.
Please note the following text in the LRIT communications document:
1.1.1.1 The parameters added by the LRIT shipborne equipment
include the latitude, longitude, Time Stamp when the position was
generated, and the shipborne equipment identifier. The "Format" of
these
parameters as outlined in table 2 indicates how the parameters shall
be
formatted while the information is contained within the LRIT message
and
does not specify the format of how the shipborne equipment transmits
the
information.
Regarding your concerns with the format of the date/time... The only
difference that I can detect between the date/time you state and what
is
in Table 2 of the LRIT communications document is the separators ("-"
versus ":") for the year, month, day, hour and minute. The separator
used to separate the year, month, etc in the date stated in table 2 is
not important and in no way linked to the format coming out of the
shipborne equipment. The format is with respect to SOAP messages
communicated along the various LRIT communication segments. CSPs for
the
IDC shall have to "build" SOAP messages complying with table 2 in the
communications document using the format from the ship borne
equipment.
The important thing with the time stamp is that seconds are not
transmitted.
Regarding your concerns with the format for latitude... We had a
discussion on your e-mail and the intention was to implement your
recommendation. I can't recall why the "seconds" component of the
latitude didn't change to decimal minutes with a precision of 2
decimal
places. The most likely reason is that I forgot to incorporate this
change in the document due to the numerous requests. My apologies on
this topic. I will make the change for latitude to decimal minutes
unless someone raises a compelling reason not to change. Any body from
the Communications group recall if there was a specific reason why we
didn't make the change (Jilian, Guy, etc.)???
I would like to high light to everyone that these documents are in
constant flux as a result of many requests from different inputs at
the
Ad Hoc meeting. Thus, it is important to fully read the documents that
come out of each meeting to ensure that any particular topic of
interest
is addressed in a satisfactory manner.
Thanks,
Craig Hayley
System Engineer
Canadian Coast Guard
709-772-7740
________________________________
From: ccglrit-gcclrit-bounces(a)lists.ncf.ca
[mailto:ccglrit-gcclrit-bounces@lists.ncf.ca] On Behalf Of Brian
Mullan
Sent: Thursday, May 31, 2007 12:35 PM
To: ccglrit-gcclrit(a)lists.ncf.ca
Subject: Re: [Ccglrit-gcclrit] June 12-14 meeting of the Ad hoc
Working
Group onEngineering Aspects of LRIT, Hamburg Germany
Thanks, Tracy
In table 2 I note that the format of date/time is still shown as
YYYY-MM-DD-HH-MM. My earlier email (attached) made comment on this.
Also
in Table 2, note appears to have been taken of my comments regarding
latitude/longitude position for Longitude only, but ignores Latitude.
We must not start requiring reformatting for transmitted data that is
already designed into existing shipboard equipment - PLEASE!
Many thanks
Brian
Brian Mullan
Head, Maritime Safety Services
Inmarsat, 99 City Road, London EC1Y 1AX, UK
Tel: +44 (0)20 7728 1464
Fax: +44 (0)20 7728 1689
Mob: +44 (0)7711 495836
www.inmarsat.com
________________________________
From: ccglrit-gcclrit-bounces(a)lists.ncf.ca
[mailto:ccglrit-gcclrit-bounces@lists.ncf.ca] On Behalf Of Peverett,
Tracy
Sent: 29 May 2007 22:27
To: ccglrit-gcclrit(a)lists.ncf.ca
Subject: [Ccglrit-gcclrit] June 12-14 meeting of the Ad hoc Working
Group onEngineering Aspects of LRIT, Hamburg Germany
Second of two e-mails
As promised, attached please find the updated LRIT Communications
specification.
Best regards
Tracy
Tracy Peverett
Senior Policy Analyst
Canadian Coast Guard
Tel: 1-613-990-4046
Fax: 1-613-998-3255
e-mail: peverettT(a)dfo-mpo.gc.ca
This email and any files transmitted with it are confidential and
intended solely for the use of the individual or entity to whom they
are
addressed. If you have received this email in error please notify the
system manager. In accordance with Inmarsat Information Security
Policy
and Guidelines on Computer use, emails sent or received may be
monitored. Inmarsat plc, Registered No 4886072 and Inmarsat Global
Limited, Registered No. 3675885. Both Registered in England and Wales
with Registered Office at 99 City Road, London EC1Y 1AX.
_____________________________________________________________________
This e-mail has been scanned for viruses by Verizon Business Internet
Managed Scanning Services - powered by MessageLabs. For further
information visit
http://www.verizonbusiness.com/uk
_____________________________________________________________________
This e-mail has been scanned for viruses by Verizon Business Internet
Managed Scanning Services - powered by MessageLabs. For further
information visit
http://www.verizonbusiness.com/uk
**********************************************************************
This email and any files transmitted with it are private and
intended solely for the use of the addressee.
If you are not the intended recipient, the email and associated
files have been transmitted to you in error: any copying, distribution
or other use of the information contained in them is strictly prohibited.
Nothing in this email may be interpreted as a contractual or other
legal commitment on the part of the Maritime and Coastguard Agency
unless confirmed by a communication signed by or on behalf of the
Chief Executive.
The MCA's computer systems may be monitored and communications
carried on them recorded, to secure the effective operation of the
system and for other lawful purposes.
If you are of the opinion that you have received this email in error,
please contact postmaster(a)mcga.gov.uk
***********************************************************************************