FW: [amsat-bb] Lock on Tracking

["Rod Smallwood" <Rod@xxxxxxxxxxxxxxxxxxxxxxxxx>]

-----Original Message-----
From: Rod Smallwood 
Sent: 11 December 2002 14:59
To: 'Dave Johnson'; ',amsat-bb@amsat.org'
Subject: RE: [amsat-bb] Lock on Tracking


Sounds good but I don't think AO40 would look for me
I think I would have to look for it! 

Having thought a bit more about it you could do it in 
hardware if you had four antennas and four receivers (or one
muxed around the four antennas). Another possibility
would be to have four feeds at different angles to
the dish. And finally there's the flat phased array
which is steered electronically. (anybody know how?)

Rod G8DGR
 


-----Original Message-----
From: Dave Johnson [mailto:Dave.Johnson@ddat.co.uk]
Sent: 11 December 2002 13:31
To: Rod Smallwood; 
Subject: Re: [amsat-bb] Lock on Tracking


Hi Rod,

An active solution might be to do the the equivalent of what deep space
satellites do when they lose lock on the earth for some reason, they
'cone'.
In other words they set up a motion which subtends a cone of the
radiation
pattern of the antenna. At some point in the motion around the cone the
signal strength will increase and that will give an indicaton of the
direction. The satellite then manoeuvres 'the cone' in than direction,
and
reduces it's diameter and continues to do this repeatedly until a lock
is
found. A cone of zero angle.

A neat trick but I'm not sure that my 5500 would cope with all than
movement!

- Dave G4DPZ


----- Original Message -----
From: "Rod Smallwood" <Rod@sbs293.customer.demon.com>
To: <amsat-bb@AMSAT.Org>
Sent: Wednesday, December 11, 2002 10:16 AM
Subject: [amsat-bb] Lock on Tracking


> Unless I am much mistaken everybody uses predictive tracking.
> Has anybody had any experience with Radar style tracking
> where the system locks on to the target (ie AO40) and follows
> it?
>
> Rod (G8DGR)
>
>
>
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