The Weather Forecasting Forum

Discussions about the latest in meteorology, programs, tools, and techniques
It is currently Mon Oct 23, 2017 10:48 pm

All times are UTC




Post new topic Reply to topic  [ 5 posts ] 
Author Message
 Post subject: Fleetcode problem
PostPosted: Sun Dec 07, 2003 10:16 pm 
Offline
Administrator

Joined: Sat Nov 22, 2003 10:47 pm
Posts: 511
A couple of people have recommended adding fleetcode, suggesting bulletins such as those at http://ftp.hb-yacht.ch/ASXX21.060600 . At this point I am unable to implement Fleetcode.

Here is the problem (you may refer to WMO Pub 306 (1.7 MB, PDF):

(1) The header is 33300, which indicates a FM 45-IV IAC code (non-abbreviated fleetcode). Therefore positions are expressed as "yyyyy", which is defined by "333x1x1" in the header.

(2) WMO provides an ambiguous scheme for finding longitude in this scheme. In our data sample, "x1x1" is 00, which means yy is LaLaLoLoK. Note that this gives only two digits with which to express longitude. In fact, LoLo specifies that the hundreds digit is deleted.

Therefore, if we get a value of "35" for LoLo, this could be either 35 or 135 degrees. If K=5, then according to K (Table 2200) we could have either 35W or 135E. This is not a sensible answer, and is unplottable.

Unfortunately I have no choice but to cease work on Fleetcode unless someone can point out a solution I may have overlooked.

Tim


Top
 Profile  
 
 Post subject:
PostPosted: Mon Dec 08, 2003 5:06 pm 
Offline
Member

Joined: Sun Nov 23, 2003 11:17 pm
Posts: 39
abandoning the ability to import fleetcodes would leave european users pretty much in the cold :(

As it is now , we have only two ways of having charts like the american users ( would ) have :

- drawing everything in manually ( might as well get a finished chart from the net,less work - unfortunately that way the cahrts are limited )

Importing analysis data from AVN-global data , howvere : grib-data is limited and as I pointed out the only way to do that is to import the whole global avn-set ( these are very large grib-files ) . DA seems to be having problems with importing such large-sized grib-datasets at this time also ( perfectly to be expected , those files can be as big as near 100 mb ) . I haven't found a site yet which splits up those sets in regions .

Fleetcodes are therefore very important for us european users.
I sure would like to see this new DA- when finished - to be as International as is possible - as it stands now : the emphasis is gradually moving towards American users .


Top
 Profile  
 
 Post subject:
PostPosted: Mon Dec 08, 2003 7:55 pm 
Offline
Member

Joined: Mon Nov 24, 2003 9:19 am
Posts: 42
Location: Maarssen, NL
Tim,

The second line of the Fleetcode (Atlantic European) dataset has is something like this:

ASXX21 EGRR 010600

Is it possible to make a hardcode in DA to use the EGRR as a key to set "k" for a file where:

k = 0 to 4 for east
k = 5 to 9 for west

I checked some archieved Fleetcode files and found EGRR on all the copies from this year.

I think that there no problems for the present as there are only two known sites for Fleetcodes: the Swiss for Atlantic and Europe and the New Zealand for the Pacific.
But I will also ask Norbet Huser (webmaster of HBYacht.ch) for his advice to read the fleetcode from his site and ask what his solution would be.

That's it,

Ton.


Top
 Profile  
 
 Post subject:
PostPosted: Tue Dec 09, 2003 9:32 pm 
Offline
Administrator

Joined: Sat Nov 22, 2003 10:47 pm
Posts: 511
Yes, consulting these people will be very important to implementing the code correctly.

I will proceed and find a way to toggle between the two formats. I am surprised that the WMO has implemented such a poor scheme but I will try to work around it.

Tim


Top
 Profile  
 
 Post subject:
PostPosted: Wed Dec 10, 2003 1:38 pm 
Offline
Member

Joined: Sun Nov 23, 2003 11:17 pm
Posts: 39
works like a charm :)

At least I tried to downloaded a set for the same timeslot as depicted on the 0600 Bracknell chart and the fronts were in the correct location . I downloaded it from the aforementioned site :
http://ftp.hb-yacht.ch/

Now , for a questiion ( not necessarily for Tim to answer !)
I sthere a comprehensive site available for these datasets aprt from the one mentione d above , that will be compatible with Tim's new import capacity ??

In other words , please post some source-URLS :)

Although the one above seems to cover most of Europe .

Can you in fact change the font for the High and low-pressure centre depiction ( those letters look very small , in essence no problem as you can use the ones available in DA itself of course )

Good work and snappy as well....


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 5 posts ] 

All times are UTC


Who is online

Users browsing this forum: No registered users and 3 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group