offshore weather via FTP

Conachair

Conachair

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One day I may have ssb/pactor setup but for now I'm stuck with satphone for weather offshore. I can get grib and metareas txt using (rather good) email reply service fom saildocs.com but using thunderbird with satphone it takes a stress inducing 3 - 4 minutes to log on, download 10kb grib. I've got command line ftp working to upload files to the website which seems quick, almost instant logon etc and have a scrip supplied generously from Jeannius of these parts to download weatherfax and grib via ftp. Now I can get grib files via ftp from http://gribs.ocens.net/ , 43kb for 3 day east atlantic, 39kb for 4 day central atlantic. Haven't timed any downloads from here yet via satphone, heartrate increases just turning the thing on.

Questions:
Has anyone timed getting a grib via FTP from http://gribs.ocens.net/ against saildocs.com email service - do you think it will be much quicker?

Any other ftp (or any low bandwidth) sources for weather which might be useful offshore?

Another option would be to have friend onshore to keep an eye on my position and txt outlook to satphone. Which would be that 4 letter word we all like to hear - FREE!

Thanks all
Paddy
 
I have ugrib but don't think it's an option via satphone. Haven't tried it but pretty sure it would use up way too much airtime. Slow enough via mobile connection and on iridium every second counts /forums/images/graemlins/frown.gif
 
I agree - every second counts. I signed up for Mailasail on the basis that it has compression built into the data transfer. Consequently when you get a grib by email, it should transfer faster than if it is uncompressed.

I have tested it but have not expended any airtime on doing comparisons.

HTH
 
I had a look at look at mailasail, seems to be a good service. Though without working it out I guessed that it would take a lot of downloads to get back the fee. The gribs from http://gribs.ocens.net/ are compressed but atlantic goes from 10n to 62n which is a little further north than I shall be going /forums/images/graemlins/wink.gif Still, quite a small file size. I wonder of there's a faster email prog, a lot of the time with thunderbird seems to be spent logging on. I think the ftp/ocens grib option should be quicker and anyway there's always weatherfax. Or listen in to Herb. And for a crossing does it really make that much difference? I'm not fast enough to run around the ocean looking for a bit more wind /forums/images/graemlins/grin.gif
 
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I had a look at look at mailasail, seems to be a good service. Though without working it out I guessed that it would take a lot of downloads to get back the fee. The gribs from http://gribs.ocens.net/ are compressed but atlantic goes from 10n to 62n which is a little further north than I shall be going /forums/images/graemlins/wink.gif Still, quite a small file size. I wonder of there's a faster email prog, a lot of the time with thunderbird seems to be spent logging on. I think the ftp/ocens grib option should be quicker and anyway there's always weatherfax. Or listen in to Herb. And for a crossing does it really make that much difference? I'm not fast enough to run around the ocean looking for a bit more wind /forums/images/graemlins/grin.gif

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I hear ya! However, you can customise your own area of interest for each of the gribs.

I have to admit that I went the Mailasail way simply because it gives me more control over what email we get too! (i.e. images and the like that people send you that would take the length of the trip to download on a sat phone!)

/forums/images/graemlins/laugh.gif
 
[ QUOTE ]
have to admit that I went the Mailasail way simply because it gives me more control over what email we get too! (i.e. images and the like that people send you that would take the length of the trip to download on a sat phone!)



[/ QUOTE ] You can do that within say, Outlook, or even later versions of Outlook Express I believe. Somewhere in 'Options' you can set that you just want to download the header. Then you can look at the sender and the title and decide if you want to download. You can also set a size threshold on what mails to automatically download so, for instance, you can automatically receive mails up to 5k and manually select everyhting bigger than 5k
 
[ QUOTE ]
[ QUOTE ]
have to admit that I went the Mailasail way simply because it gives me more control over what email we get too! (i.e. images and the like that people send you that would take the length of the trip to download on a sat phone!)



[/ QUOTE ] You can do that within say, Outlook, or even later versions of Outlook Express I believe. Somewhere in 'Options' you can set that you just want to download the header. Then you can look at the sender and the title and decide if you want to download. You can also set a size threshold on what mails to automatically download so, for instance, you can automatically receive mails up to 5k and manually select everyhting bigger than 5k

[/ QUOTE ]

Thanks Mike. Yes You can download the headers only but since negociating with the server is a big part of the process, I prefer to get the whole lot. Mailasail allows me to reject attachments at the server level /forums/images/graemlins/smile.gif

Also, file size limiting only works for sending emails and it is really to break the messages up.

Either way - on the Iridium connection I get duplex data transfer using their client-side mail server and protocols so I know I use less time.

Thanks for the tip! /forums/images/graemlins/ooo.gif
 
Hi, Ed from MailASail here.

Great to hear that people like our system, but do note that the basic weather system is free and you don't need to be a subscriber to use it. Think of it as two systems - we use a weather responder via email as a free system that simply replies *instantly* to requests with the data you need. The second bit is that we sell (very inexpensively) a very fast email subscription which gives you a big speedup downloading emails - the second bit is optional and everyone gets a free trial before they buy - if you dont think its worth it then don't buy it!!

With regards to what to use. Generally all grib data is coming from the US GFS model. GRIB itself is a generic standard, but with most providers charging for the data, this tends to narrow the market down to just the US which offers completely free data from one of a number of models, the main ones being GFS or NWW3. UGrib offers only GFS, but you can get GFS or NWW3 from either mailasail or from saildocs. All of these services are free and will allow you to select exactly which data you want (mailasail and saildocs require you to type in the posiition, ugrib allows you to select it on a map)

The main disadvantage to ugrib (on a sat phone) is that it seems to take a very long time between you choosing your data and it starting to download. I am not 100% sure, but it sseems that there is some kind of ftp queuing system on the backend which causes some delays? With mailasail the turnaround time is typically less than 1 second and this should be an advantage. However, both are free so try both and decide for yourself

Note that we are just about to launch a new weather site - I hope this is going to be a quite exciting expose on what weather sources are available and how to access them - keep an eye on our website in about a weeks time...


Coming back to the original question though - I would expect Iridium to download 20KB/min, and with compression these rates are achievable and even beatable. So for 10KB of emails I would expect to be online for 10 seconds to connect to the internet, plus around 30 seconds to download the data and then instant disconnect. If you are spending 3-4 mins to do this then you would be far better off to try out our system... There is a video on our site demonstrating sending 10 (small) emails and receiving 8 and the whole thing takes about 30 seconds of chargeable time (ie 10 seconds to dialup, plus about 20 seconds to send and then receive the data) - this is what you should be aiming for!

Good luck

Ed Wildgoose
 
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