Bill Pitz wrote:
>
> Barry Oliver wrote:
>
>>
>> One application I have wondered about is RV campers. You know those
>> people whose permanent address is a mailboxes etc. or an RV park.
>> Plenty of RV's have satellite dishes, and have learned how to align
>> them every night, I suppose it couldn't be any more difficult to do
>> with an internet connection. But then I suppose the real purpose of
>> living like that is to remain off the grid....
>>
>
> Depends on the particulars of the service. For 2-way data, you can
> generally get aligned well enough to keep anyone from noticing. With
> most setups, though, they are selling bandwidth on two different
> polarizations (usually horizontal/vertical). This requires
> "cross-polarization" be performed to minimize your potential
> interference with the other pole that contains other paying customers.
> (Like I said, though, this usually can be done yourself without anyone
> noticing). The other issue with this is that your modem must know it's
> coordinates in order to synchronize its transmissions. (The precise
> amount of delay varies depending on your position on the earth -- which
> directly correlates with your distance from the satellite)
>
> There's also circular (vs. linear) polarization, which doesn't require
> this step by nature -- but naturally, the transponder space is more
> expensive.
>
>
> They do, however, make auto-pointing antennas that can be had in the
> sub-30K range if you find the right source. (For DirecTV, they've got
> virtually flat antennas that will auto-point while you're driving for
> only a couple grand). These point and polarize themselves because they
> contain a GPS controller unit that is capable of calculating your exact
> pointing angle and polarization angle based on the position of the sat
> and your position on the earth. We've got them on a couple of demo
> vehicles, and have sold them to a number of clients. They work pretty
> darn well.
>
> -Bill
>
Damn that sounds cool
This archive was generated by hypermail 2b29 : Sat Oct 01 2005 - 12:50:23 EDT