I think sailors would want Grib files or Grib2 files weather files.
These should be highly compressed.
Currently people download them from free and commercial providers using their Inmarsat sat-phones so I guess in theory it should be possible to transmit the whole world say a two day ahead grib weather prediction using the Outernet L-Band transmission.
Sam do you have any idea how much date the whole world would be as a grib file 2 days ahead?
Seasalt, I know what you mean, North Atlantic would be 105kb, Assume Pacific would be the same.
The idea behind using this instead: http://www.opc.ncep.noaa.gov/shtml/A_48hrsfcbwug_mobile.gif is that it’s viewable by anyone without a special piece of software. It’s also maybe a bit easier to interpret without specialist knowledge and less than half the size of the grib.
Ideally I guess you’d have the gif and the grib. But bandwidth is very valuble… For me the image would be worth having if offshore in a small boat.
If there’s some way the bandwidth could be paid for, then I see no reason to restrict it. In theory, if the cost of $X for bandwidth can be shared among all interested users evenly, then there’s potential for doing this cheaper than sat-phone-based solution. That said, our technology is still quite alpha, so it would take a while before we can ask for money for this type of service.
The world weather model updates the world “Free” Grib files every six hours.
The grib weather prediction I believe is possibly up to eight days prediction.
The model can also have different levels of detail. (Distance between information points etc.
The main information sailing boats want from Grib data is wind information.
If Outernet l-Band is always connected and receivable on a moving boat. ( A big unknown) Possibly with either gyroscoped antennas or Helical type omni antennas.
Then a two day / 3 day prediction would be probably enough. As the 2 day prediction window would be updated by the world weather model every six hours and transmitted by Outernet every 6 hours.
The whole world weather would not be required to be transmitted . The poles could be ignored, to save transmission data.
I believe this would be a massively popular transmission of Grib weather data.
@Seasalt Are you able to receive L-band with the radio/amp that was sent? The frequency changed to 1545.525 MHz. We’re adding our third beam next week, which will provide full global coverage.
In that case I’d vote for images, they’d be useful to a much larger group of people, hundreds of thousands rather than a couple of thousand:
What happens at sea to a large extent determines what happens on land. So someone with a bit of knowlege /initiative could use them to usefully suppliement the land based forecast.
In fact it would be really cool to broadcast a version of this creative commons article on how to read a weather map once a year or so. Could make the images much smaller. There’s French/ Spanish/ Russian version at the bottom too.
The grib file i created using Zygrib and NOAA-GFS (standard data) of the WHOLE world, with wind arrows showing the strength and direction of Wind.
It consists of 12 sets of 6 hr predictions of wind for the next 3 days.
The spacing on the wind arrows is 120Nautical Mile apart.
A user using OpenCPN(Open-source Navigation Package. Zygrib (GPL3 Open Source) or even in future Open Street Map or Open SeaMap could automatically super-impose the Grib Weather Data onto a Chart and create their own Weather Pictures.
This dat would be immensely beneficial to all Mariners.
But a user could not reverse a weather picture and create 3 days of gribs.
My vote is definitely go with the Grib weather file.
The Data is freely available every six hours.
Boaters rich or poor, Europe or Africa all over the world want accurate weather.
Accurate Weather will help save lives at sea .
The “Grib2” format allows for Data sets to be broken up and recombined.
Outernet could transmit small geographical data sets which could be easily combined.
Many free open source projects already exist to manipulate the data.
The data may already be available as smaller subsets and Outernet may only have to mirror a government Weather Bureau data share every six hours.
Someone like SOLAS “Safety Of Life AT SEA” or the UN might pay for this as a Community Service Obligation to Mariners.
Is there a place where we can grab new grib files every six hours? We’re ready to start sending them now. We have 1000 amplifiers on Amazon, as well as that many antennas. Several different rtlsdr radios will be able to support Outernet reception.
Could someone share a set of grib files? Is it possible to view them without a specific type of viewer? The file size limit will likely be around 100kB.
It’s only possible to view gribs with a dedicated viewer. That’s why I personally think the images I linked above are a more useful solution. Anyone with a browser can make sense of them.
Typically a GRIB is just wind or wave information, great for sailors, but not all that useful for the general population in my view.
The images above show pressure and storm systems in a way that are intelligible to a layman, and allows someone with a basic knowledge of weather to make half decent forecasts.
that seems doable? 