NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Deviation Card with GPS
From: Lu Abel
Date: 2006 Jul 26, 08:42 -0500
Bill wrote:
> I fully agree. And at 3+ nm a masthead rolling through 30d won't much
> affect a bearing. Given display in 1d increments, below the noise level.
> Set anchor with the wind holding the bow in one direction and old swells
> coming from another point, and try use a GPS as a compass. Fruitless.
> Almost all the motion from a masthead antenna will be lateral.
Bill: Any idea why the GPS antenna was mounted on the masthead?
GPS simply needs a view of the sky. It seems to me that that view
doesn't change a whole lot going 50' up a mast.
Worse, unless the antenna was an active antenna (ie, had an amplifier in
it), there would have been severe signal loss (on the order of 10dB or
more [that's a factor of 10!]) coming down the wire into the GPS set.
Lu Abel
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From: Lu Abel
Date: 2006 Jul 26, 08:42 -0500
Bill wrote:
> I fully agree. And at 3+ nm a masthead rolling through 30d won't much
> affect a bearing. Given display in 1d increments, below the noise level.
> Set anchor with the wind holding the bow in one direction and old swells
> coming from another point, and try use a GPS as a compass. Fruitless.
> Almost all the motion from a masthead antenna will be lateral.
Bill: Any idea why the GPS antenna was mounted on the masthead?
GPS simply needs a view of the sky. It seems to me that that view
doesn't change a whole lot going 50' up a mast.
Worse, unless the antenna was an active antenna (ie, had an amplifier in
it), there would have been severe signal loss (on the order of 10dB or
more [that's a factor of 10!]) coming down the wire into the GPS set.
Lu Abel
--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to NavList@fer3.com
To , send email to NavList-@fer3.com
-~----------~----~----~----~------~----~------~--~---
