[time-nuts] Ublox F9P PPS output
Bob kb8tq
kb8tq at n1k.org
Tue Feb 12 00:11:36 UTC 2019
Hi
Now for a bit more of the storyt :)
If you take your 24 hours worth of data from the F9P and send it to NRCan for analysis,
they come back with a plot and data file that shows the clock running about +/- 2 ns over
the 24 hour period. The ADEV at one second is about 10X better than what Mark’s
measured data on the 1 PPS shows.
Obviously more research is called for :)
It is also interesting to note that while the F9P may not hit the specs on the F9T in a way.
that a TimeNut might like, it does hit them in a fashion that would back up all the marketing
claims.
One good piece of news: The “cheap” eBay antennas from China seem to do just as well as
a “proper” survey antenna. The signal to noise numbers are essentially same / same. The
error eclipse comes out in the same sort of mm-ish dimensions. Plenty good enough for timing.
Bob
> On Feb 11, 2019, at 5:28 PM, Mark Sims <holrum at hotmail.com> wrote:
>
> I got in a Ublox F9P multi-band receiver from Sparkfun. Lately I've been testing the 1PPS output. This data is from the F9P tracking GPS and GLONASS L1 and L2. The PPS was measured by a TAPR TICC clocked by an HP-5071A. BTW, processing the raw F9P measurement data with CSRS-PPP produces lat/lon/alt location error ellipses in the 5/10/20mm range with my horrible antenna location. Bob got 3/6/12 mm.
>
> The GREEN plot is the PPS output from the F9P. The ORANGE plot is that value adjusted by the sawtooth correction. The BLUE line is the PPS ADEV plot. It is interesting that the reported F9P sawtooth values don't average to 0.000 nsec.
>
> #
> # Device: Ublox F9P receiver
> #
> # Unit type: TAPR TICC
> # Serial number:
> # Firmware ver:
> # Board ver:
> # EEPROM ver: 0
> # Mode: Timestamp
> # Ref clock: HP-5071A
> #
> #
> # Unit type: Ublox F9 receiver
> # SW: EXT CORE 1.00 (eba0dc
> # HW: 00190000
> # ROM 1: ROM BASE 0x118B2060
> # ROM 2: FWVER=HPG 1.10
> # ROM 3: PROTVER=27.10
> # ROM 4: MOD=ZED-F9P
> # ROM 5: GPS;GLO;GAL;BDS
> # ROM 6: QZSS
> #
> #
> # PPS ADEV for 84955 points - sample period=1.000 secs - bin count:14
> # 1.000 tau 3.4621e-009 (n=43197)
> # 2.000 tau 1.7355e-009 (n=43195)
> # 5.000 tau 6.8783e-010 (n=43189)
> # 10.000 tau 3.4520e-010 (n=43179)
> # 20.000 tau 1.7183e-010 (n=43159)
> # 50.000 tau 7.0574e-011 (n=43099)
> # 100.000 tau 3.6007e-011 (n=42999)
> # 200.000 tau 1.8072e-011 (n=42799)
> # 500.000 tau 7.2585e-012 (n=42199)
> # 1000.000 tau 3.6834e-012 (n=41199)
> # 2000.000 tau 1.8453e-012 (n=39199)
> # 5000.000 tau 7.4818e-013 (n=33199)
> # 10000.000 tau 3.5851e-013 (n=23199)
> # 20000.000 tau 1.6814e-013 (n=3199)
> #
> # PPS HDEV for 84955 points - sample period=1.000 secs - bin count:13
> # 1.000 tau 3.6499e-009 (n=43196)
> # 2.000 tau 1.8313e-009 (n=43193)
> # 5.000 tau 7.2455e-010 (n=43184)
> # 10.000 tau 3.6413e-010 (n=43169)
> # 20.000 tau 1.8064e-010 (n=43139)
> # 50.000 tau 7.4202e-011 (n=43049)
> # 100.000 tau 3.7939e-011 (n=42899)
> # 200.000 tau 1.9034e-011 (n=42599)
> # 500.000 tau 7.6306e-012 (n=41699)
> # 1000.000 tau 3.8724e-012 (n=40199)
> # 2000.000 tau 1.9281e-012 (n=37199)
> # 5000.000 tau 7.8140e-013 (n=28199)
> # 10000.000 tau 3.5864e-013 (n=13199)
> #
> # PPS MDEV for 84955 points - sample period=1.000 secs - bin count:13
> # 1.000 tau 3.4621e-009 (n=43197)
> # 2.000 tau 1.2295e-009 (n=43194)
> # 5.000 tau 3.0416e-010 (n=43185)
> # 10.000 tau 1.0540e-010 (n=43170)
> # 20.000 tau 3.8724e-011 (n=43140)
> # 50.000 tau 1.5815e-011 (n=43050)
> # 100.000 tau 7.9180e-012 (n=42900)
> # 200.000 tau 3.5732e-012 (n=42600)
> # 500.000 tau 1.1746e-012 (n=41700)
> # 1000.000 tau 5.9070e-013 (n=40200)
> # 2000.000 tau 3.3584e-013 (n=37200)
> # 5000.000 tau 1.4796e-013 (n=28200)
> # 10000.000 tau 5.1583e-014 (n=13200)
> #
> # PPS TDEV for 84955 points - sample period=1.000 secs - bin count:13
> # 1.000 tau 1.9989e-009 (n=43197)
> # 2.000 tau 1.4197e-009 (n=43194)
> # 5.000 tau 8.7803e-010 (n=43185)
> # 10.000 tau 6.0855e-010 (n=43170)
> # 20.000 tau 4.4715e-010 (n=43140)
> # 50.000 tau 4.5654e-010 (n=43050)
> # 100.000 tau 4.5714e-010 (n=42900)
> # 200.000 tau 4.1260e-010 (n=42600)
> # 500.000 tau 3.3908e-010 (n=41700)
> # 1000.000 tau 3.4104e-010 (n=40200)
> # 2000.000 tau 3.8780e-010 (n=37200)
> # 5000.000 tau 4.2712e-010 (n=28200)
> # 10000.000 tau 2.9781e-010 (n=13200)
> #
> #
> # PPS MTIE for 32768 points - sample period=1.000 secs - bin count:16
> # 1.000 tau 6.5166e+000 (n=32768) (nanoseconds max time interval error)
> # 2.000 tau 6.5166e+000 (n=32766)
> # 4.000 tau 6.5166e+000 (n=32764)
> # 8.000 tau 6.5166e+000 (n=32760)
> # 16.000 tau 6.5166e+000 (n=32752)
> # 32.000 tau 6.5166e+000 (n=32736)
> # 64.000 tau 6.5166e+000 (n=32704)
> # 128.000 tau 6.5166e+000 (n=32640)
> # 256.000 tau 6.5166e+000 (n=32512)
> # 512.000 tau 6.5166e+000 (n=32256)
> # 1024.000 tau 6.5166e+000 (n=31744)
> # 2048.000 tau 6.5166e+000 (n=30720)
> # 4096.000 tau 6.5166e+000 (n=28672)
> # 8192.000 tau 6.5166e+000 (n=24576)
> # 16384.000 tau 6.5166e+000 (n=16384)
> # 32768.000 tau 6.5166e+000 (n=1)
> #
> #
> #
> # Plot statistics:
> #
> # Sawtooth:
> # rms: 2.257634439 ns
> # avg: -0.109084539 ns
> # sdv: 2.254997522 ns
> # var: 5.085013825 ns
> # min: -4.047000000 ns
> # max: 3.808000000 ns
> # span: 7.855000000 ns
> #
> # Tpps: (measured PPS deviation form 1.0000 seconds)
> # rms: 3.255180518 ns
> # avg: 0.000165522 ns
> # sdv: 3.255180514 ns
> # var: 10.596200180 ns
> # min: -8.712959243 ns
> # max: 8.774804883 ns
> # span: 17.487764126 ns
> #
> # Tadj: (PPS measurement adjusted for sawtooth error)
> # rms: 2.305958761 ns
> # avg: -0.108871574 ns
> # sdv: 2.303387242 ns
> # var: 5.305592789 ns
> # min: -5.626733815 ns
> # max: 5.401032108 ns
> # span: 11.027765923 ns
> #
> # Sats: (tracking GPS and GLONASS)
> # rms: 14.592751290
> # avg: 14.485540834
> # sdv: 1.765643501
> # var: 3.117496974
> # min: 9.000000000
> # max: 19.000000000
> # span: 10.000000000
> #
> <f9padev.gif>_______________________________________________
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