Re: [time-nuts] nuts about position

In message , Mark Sims writes: >The effects of things like antenna position changing a couple of cm due to >expansion and humidity effects are swamped by the receiver accuracy and noise. Short term: Yes. Long term: No. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20

[time-nuts] nuts about position

The typical receiver default self-surveys of 30 minutes to 2 hours are not ideal. They will not include a lot of satellites or the effects of multi-path over time. A survey of at least 12 hours is needed to include all the sats. 24-48 hours is even better. The effects of things like

Re: [time-nuts] nuts about position

In message , Mark Sims writes: >The next thing I want to try is a receiver self-survey vs the post processed >results... I fell into that trap many years ago as well :-) The post processed result eliminates and compensates for a lot of effects which are invisible to the receiver,

[time-nuts] nuts about position

The tripod is a survey grade tripod on a limestone terrace (in a horrible location for an antenna). Heather's precision survey uses the receiver's reported position data. It does not take advantage of carrier phase/pseduorange/doppler data and post-processing. Unlike the simple averaging

Re: [time-nuts] nuts about position

Hi Hmmm …… that’s a very big difference between the RINEX and the “precision survey”. How do each compare to other receivers on the same antenna ( and super duper stable mount) ? Even with a tripod on the grass, meter level variations likely are not the tripod’s fault. :) Bob > On Jun 5,

[time-nuts] nuts about position

I did Lady Heather's 48-hour precision survey on an NVS-08 receiver and collected RINEX data at the same time. The NVS was tracking GPS and SBAS satellites. The RINEX result had lat/lon/alt error estimates of .175/.153/.396 meters. The difference between Heather's precision survey results and

[time-nuts] Raw phase data of super-5065

Attila, I will send you some raw data. Attached is a combined plot of a recent successful filter installation. Only 20 to 25% of units will be improved with the filter mod. Two things to look for. 1- The short term stability at 1 Sec (Allan Deviation) should drop from the 2X10-12th range down

Re: [time-nuts] Possible new run of TNS-BUF High Isolation, Low Noise Buffer Amp boards

Good news -- we had enough orders to justify doing a small production run of the TNS-BUF isolation amplifiers. We'll be placing the order with our contract manufacturer this week, and expect delivery in six to eight weeks. There will be a few extra boards available, so if you haven't ordered

Re: [time-nuts] Raw phase data of super-5065

Hi It is pretty well known that without “help” ( beyond the filter stuff on the super) the 5065 has fairly poor temperature stability and somewhat variable response to pressure and humidity. Taking two samples right off the production line likely would have given you different long term data

Re: [time-nuts] Raw phase data of super-5065

Hi Attila, I am doing the long therm stability test on a couple of HP5065, one original A type, the second B or "super" compared with my best long therm stability, a GPSDO HPz3816A. This test will be 30 days long. It is a second test, with a second couple of HP5065A/B, to verify the

Re: [time-nuts] a newbie question: where can I purchase 794.7 nm VCSEL for building CPT rubidium clock?

On Mon, 4 Jun 2018 21:31:56 +0800 mimitech mimitech wrote: > I'm planning to build a CPT (coherent-population-trapping) rubidium clock > as my next hobby project. The main purpose is to learn the principles > behind CPT rubidium clock, and hopefully got similar or better performance > than