Outernet for sailors (weather forecast grib files)


#41

Wikipedia" “The box has a scalar horn antenna (the funnel with concentric rings, left) which collects the microwave beam and directs it into a waveguide, a short closed metal pipe. Two small metal pins project into the waveguide from the circuit board; these serve as antennas which convert the microwaves to radio”

Could we just modify the waveguide to be wider? So that the Ku Outernet could work on a boat.


#42

This was where my earlier question regarding DISEqC question was going. A controller could use a DISEqC switch to select between different LNBs.

–Konrad, WA4OSH


#43

Davey
Switch 4X1 DiSEqC Satellite Dish FTA Receiver 4 in 1 Multi LNB LNBF

Connect up to four LNBFs (or dishes) to your receiver using our 4x1 DiSEqC switch.

Frequency Range: 950-2400MHz
Insertion Loss: 3dB
Power Passing: 500mA Max
DiSEqC 2.0

Quick amazon search.

Are all 4 inputs fed thru at the same time?


#44

As this is going to be quite narrow BW transmission from the bird, you will probably need the PLL type LNB.
Very cheap this days.
Do not worry for the Diseq and other mentioned problems. You will just need to orientate the LNB for the proper polarization.
The LNB original corrugated horn should be enough ti get the good signal.
Making the horn antenna bigger you will just make your antenna beam narrower and you do not want that on the boat.

As you are on the small boat and you do not changing your position so fast during the day, a small arduino board can be enough to azimuth point the antenna to the right direction.
The elevation can be set manually and corrected every while, once a week.
If your boat is heavily pitching or rolling then you may consider making a small gyro setup to point your feed always to the sat using the arduino or raspberry pi.


#45

This is what a DiSEqC switch does on a conventional FTA satellite setup. Think of it as a four pole selector switch controlled remotely over the coax by sending 22KHz data over the power supply feed to the LNB. You select which LNB you want to receive from the controller. Outernet does not have DiSEqC capability, but what if there was a “smart” electronic box that could?

diseqc_diagram

Since the beamwidth of the receive LNBs are fairly wide, a sofware controller can select between the LNBs based on received signal strength. It was just an idea I was throwing out there.

–Konrad, WA4OSH


#46

One PLL type LNB will come with the DreamChaser 3.0.

Sure, if you don’t want the DiSEcQ solution, the other solutions I can think of are

  1. To manually change the position of the antenna as needed,
  2. To rotate the antenna’s azimuth and elevation,
  3. To use a phased-array antenna that can do Ku-band beam steering.

–Konrad


#47

I know Oneweb is going to use a $300 mobile ground station with a steerable phase array. To communicate with their moving satellites.

Do you know of any one offering these steerable antennas now?


#48

I live in the Seattle area. There are three companies that are making steerable arrays: Kymeta, Echodyne and Pivotal. I have heard a lot about their products, but have not seen them demoed yet.

I was given a KLH TracVision antenna. I may repurpose it for Outernet.

–Konrad, WA4OSH


#49

This is conceptually possibly, but the feed network required to create such an array must be very precise. This is also how some antenna systems on LEO satellites are designed.


#50

$300 is a lot. It works be cheaper and simpler to make a motorized antenna, similar to what is used by RVers to watch DirecTV.


#51

Current motorized Antennas on moving RV’s are aiming at Geostationary satellites.

The supposedly proposed $300 Phased array Transmit / receive antennas of Oneweb will be on a moving vehicle aiming at MOVING LEO satellites.

$300 for a transmit receive Oneweb mobile based data sounds ok to me.


#52

@syed, would it be possible to have the weather app show wave height? The earth.nullschool.net site shows it. This is the only information missing that would make the weather app useful to mariners.

Also, would it be possible when the DC3 goes into production, to have the weather data transmitted twice a day on a set schedule?


#53

@oceandweller007 The software that runs on the earth.nullschool.net website is different from what is available in the repo. We can send the grib-files, but the viewer won’t display them. However, any external viewer could be used to display the gribs.


#54

That’s great! I thought it was either/or since the grib files I see on the DC3 have limited data. Maybe they’ll update the app in the repo so the same weather information won’t have to be transmitted in 2 formats. I’ll try to contact the devoper and see if he’s working on an updated version.


#55

The developer does have an updated version, he just hasn’t released it as open source.