[time-nuts] Positional accuracy of the M12+T

[Magnus Danielson]

From: bg at lysator.liu.se
Subject: Re: [time-nuts] Positional accuracy of the M12+T
Date: Fri, 5 Jan 2007 00:21:39 +0100 (CET)
Message-ID: <5655.202.64.189.90.1167952899.squirrel at webmail.lysator.liu.se>

> On Thu, January 4, 2007 22:56, Magnus Danielson said:
> >> Can't wait for a civilian L2.....................
> 
> > freq receiver. In future we might actually see L2/L5 receivers with no L1
> > since
> > that might actually be more economic. L2 and L5 is only 51.15 MHz apart
> 
> But you actually want the carriers far away from each other to get a good
> iono compensation. Do not know much you will actually loose doing a L2/L5
> recevier instead.

Now, didn't I say it was the cheaper solution? :-)

You gain some and you loose some. The somewhat different RF paths, hazzle with
different group delay etc. etc. as well as the cost of double RF paths and
double frequency choke ring is reduced at the cost of a less accurate measure
for the ion value. It will still be a fantastic improvement over single
frequency model only receivers.

So, in the future we can look forward to a much more diverse field of civil
receivers:

L1 only
L2C only
L5 only (I am not sure from the top of my head if this one is in ICD)
L1&L2C combo
L2C&L5 combo
L1&L5 combo (I am not sure from the top of my head if this one is in ICD)
L1&L2C&L5 combo

Toss in creative use of all the measurements, dead reckoning on few sats etc.

Cheers,
Magnus