[time-nuts] GPS usable for weather forecasting?
lists at rtty.us
Sat Mar 30 11:20:03 EDT 2013
Ahhhh, but they did recover the code in addition to the carrier frequency. Given enough gain (and thus directivity) they were able to capture the full transmission from a single bird. They could not pull the almanac data off of it, but the sat's orbital parameters are relatively easy to come up with.
If I remember correctly they came up with some pretty impressive timing numbers. The paper didn't mention any navigation results (gee… I wonder why…). It was the first public paper I attended that started chipping away the value of selective availability.
On Mar 30, 2013, at 10:26 AM, Jim Lux <jimlux at earthlink.net> wrote:
> On 3/30/13 5:31 AM, Bob Camp wrote:
>> If you go back into the papers from the early 1980's there is one where they used a high gain antenna and no knowledge of the coding scheme to pull timing off of GPS. I believe it was at White Sands, but that could be wrong.
> One can just run it into a squaring circuit and recover the carrier, for instance. Recovering accurate carrier frequency isn't going to help you navigate a ICBM to a hardened target. Knowing the P-code is.
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