Thursday, September 27, 2012

Digital Image

This is indeed what you can call a digital image... Just take a step back in case it is not obvious to you. Or forward actually, it depends on what you missed. ;0)
Click here to see it in full.
You can do your own, just go to text-image.com.

Thursday, September 13, 2012

Routing now avoiding land

Sounds obvious, I know, but the routing is now - on request - able to avoid land.

The feature is being developed - ie it works on my machine - and will be available in beta soon (in 3.0.0.5).
There will be some limitations for the inland seas, like Caspian, Aral, Black Sea, Great Lakes... But that should beOK for the rest of us.
As always, the code will be available on Google Code.

Thursday, September 6, 2012

Google Locator for everyone

The Google Locator is this application we used during the trip to show our position on Google Maps in the blog (this blog) we were feeding from SailMail.
It is now available to whoever wants to use it, you just have to register.
To register, go to http://donpedro.lediouris.net/php/locator/idform.html and fill out the form.
(All images below are clickable, to enlarge them)


Once this is done, you can use the Google Locator available in the Navigation Desktop. You need to set your Boat ID in the preferences

When you hit the button "Generate URL", the URL you need is in the clipboard.

You can paste it in an email, or use it as it is. Here is the kind of renderings it produces in a browser


You can try it for yourself.
Enjoy!


Wednesday, September 5, 2012

How SailMail works

By popular demand... here is a quick post explaining how we can send and receive emails when at sea. We have been successfully using SailMail.
The SSB is using an analogous signal. Emails are digital data. That is why you need a modem (MOdulator-DEModulator) between the radio and the laptop, to convert the analogous signal into a digital one, and vice-versa.

So, on the boat, you need: a laptop, a modem, an SSB, with its antenna. You also do need the SailMail client program, which knows how to communicate with the modem and the SSB. All details about that are given on the SailMail web site.

The SailMail association has a network of land radio stations, which can receive the signals emitted by the boats. The land stations also have a modem, and are connected on the Internet. The emails rely on the Internet. It is like if the land stations had two faces: one facing the sea (with the SSB), and one facing the web (with the Internet connection).

What happens when the boat sends an email:
On the boat, you compose your email, and you put it in your outbox. Then you turn your SSB on, and you use the SailMail client program to contact a land SailMail station.
When the contact is established, the messages sitting in the outbox go through the modem and the SSB to be streamed to the land station. On receive, the land station then turns the messages back into digital files, and uses its Internet connection to post them on the web. From there, it's the usual email story.

What happens when an email is sent to the boat:
Someone has been sending the boat an email, using its @sailmail.com address.
When boat is establishing a connection with a land station - just like above - the land station is converting the digital emails sitting in your SailMail inbox into an analogous signal, so they can be streamed to the boat.
On the boat side, when those messages are received, they're converted into emails, and put into your SailMail client inbox on your laptop. That's it!

The radio transmission is very slow, compared to what DSL and others can provide.
Remember the dial-in time? Well, divide it by ten, and you're not even close...
That's why SailMail is appropriately cutting any attachment to the incoming emails..., and that's why, if you reply to a SailMail email, please do not hit the reply button without cutting the original message! Thank you.
A SailMail subscription grants you 90 minutes of transmission per week. Transmission time also include the time it takes to receive unwanted messages (like the original message, the one you replied to without cutting it). Thanks again.