I have seen algorithms that use a a-priori knowledge of the LO's ADEV properties to estimate the GPS's jitter and to adjust the loop time constant according to that. Ok, if you are referring to something like that. But how would you solve the system of equations with TWO unknowns (LO and GPS jitter) if you have only ONE information?

.] + Timebase Error × Interval + Trigger Error) 25ps single shot resolution (31 times worse than DTS) 53132A: 150ps resolution, at 100ps uncertainty (RMS) (187 times worse resolution than DTS units) Ebay Prices for clean, working units: Wavecrest: units were sold for $350, $500, $900 in the last years SR-620: estimated $1000++ HP53132A

For typical conditions the propogation delay for WWV cannot be estimated much better than the tens of microseconds; combining WWV with a better "absolute" clock in fact lets you study propogation by studying the shifting of the various ionospheric layers. (There have been ham operators who do this, including me!) Tim. (N3QE)

The thermal resistance of a length of wire can be estimated by measuring its electrical resistance and dividing it by the product of the thermal conductivity and electrical resistivity.

Your cellphone probably has what's called an "assisted GPS" receiver, where the cell system tells the receiver in the phone initial estimates of code phase as well as which satellites are in view. That is, a lot of the initial acquisition steps are already done. (it reduces nanojoules/fix dramatically, and that's important in a cellphone..

If you plot the satellite count and DAC voltage (and along with the PPS error estimate) you will see that the DAC voltage changes with every satellite constellation change. This causes the oscillator to change frequency.

Based on my experience with flood damaged electronics, your estimate for working units may be a bit high if they were under long enough to get well soaked. Bob On Aug 4, 2010, at 1:04 AM, jim stephens wrote: > I have access to a large number of these units (~600).

The only added steps are an independent measurement of the switched gain / gain flatness and a short circuit input check to estimate the noise floor. Both are an initial setup / one time only sort of thing with most amps.

However better estimates of the beat frequency transitions than that achievable using a 5370A to measure the relative delay between the mixer output transitions are necessary. CERN make all the required DDMTD VHDL code freely available.

If the robot moves then it can update the running means by dead reckoning and errors in the dead reckoned estimate will get corrected eventually by GPS GPS is never going to be exact. Or I should say you don't know the exact lat. long. for every place you want to go.