I wanted a simple way to download grib via Iridium
without ongoing subscription costs. I had planned to first try Iridiums Direct Internet
, but found it lacking, in fact I couldn't connect at all. Probably because of all the programs on my computer trying to access the connection. I tried turning off updates, apple, printers etc etc, but it was pointless. I think the only option is a firewall. I purchased an Iridium
router and after a bit of mucking around setting it up it seems to work very well. It costs around $180 but is a one off fee so no subscription. It has email
and browser software
(downloaded) and a email@example.com email
account (which is only accessible via iridium, i.e. you cant log into the email account via standard internet
I also downloaded weather4D for ipad
which seems to be a very good grib program. One of the best features is that is shows the Iridium satellite
orbits in real time so you can time your connection for the best data speeds.
I haven't yet done a direct grib download into weather4D but it seems simple enough. There is a direct button to ask for a grib using Axcesspoint.
I have downloaded some gribs to the axcesspoint email account, and a 30Kb file took about 3 1/2 minutes to download from saildocs.
I like to use zygrib as well and the file sizes are similar, you can also request zygrib gribs via email and the format is a bit more intuitive, better layout than the saildocs request method. The easiest method is using the zygrib program, simply tick boxes for required data and drag a square around the area. I think weather
4d is similar so I will try that out as well.
50Kb allows for 3-4 days of wind
, waves, pressure at 6 hr intervals for an area the size of the attached picture which is around 1500M x 1500M
so each image is about 5kb.
I also noticed weather4d will open the zygrib format gribs as well as the saildocs formats. It was mentioned that Zygrib may have better compression
, but I tested both formats and there isnt much difference, saildocs may be slightly smaller files for the same data.
I wasted about 30 minutes of airtime stuffing around before getting the axccespoint. My reccomendation is get it straight away. Its also perfect for using cross platforms as its a simple wifi
network, so Macs, Ipads, windows can all connect easily.
I have a couple of things id like to sort out if anyone has the answers
- how to easily send files between PC and ipad
over wifi so I can download and share the grib file between hardware
- how to set the axcesspoin firewall to allow zygrib axcess so I can download directly to the program instead of sending/recieving emails
BTW, the satellites move fast! from the beginning of a good signal to the end is only about 5 minutes, and I would guestimate 10 minutes in between average, so its definitely worthwhile to have a program to view the satellite
orbits in realtime. I downloaded a couple for the PC but they were very clunky compared to the weather4D one.