[time-nuts] Spacecraft Timekeeping
jimlux at earthlink.net
Wed Mar 9 09:15:29 EST 2011
On 3/8/11 11:05 PM, Magnus Danielson wrote:
> On 03/09/2011 06:08 AM, Kevin Watson wrote:
>> Hi All. Thanks for responding. There are quite a few GPS receivers that
>> will work outside of the usual commercial-grade GPS limitations, but I'm
>> not too sure I need such a receiver. As my application is to just
>> accuratly time-tag messages for a data recorder, my thinking is to allow
>> a ruggedized GPSDO to stabilize on the pad before launch, and then just
>> before launch force the GPSDO into holdover mode and act as the PTP
>> grandmaster for the onboard computers until we reach orbit. Once on
>> orbit I have other means to synchronize the PTP grandmaster.
> Why carry the dead weight of something unusable in orbit.
> Drop the receiver and antenna out of the equation and just provide a
> timing signal on launch pad...
I'm going to guess that you want a GPS receiver on orbit for other
reasons (like to know where you are, if your IMU or star tracker dies)
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