From: "Tom Van Baak" <[EMAIL PROTECTED]> Subject: Re: [time-nuts] Oops - wrong URL for tvb plot! Date: Tue, 10 Apr 2007 14:26:27 -0700 Message-ID: <[EMAIL PROTECTED]>
Tom, > I can see the danger now of a plot without any accompanying text. > The raw data for the three 12 hour Motorola receivers is here: > http://www.leapsecond.com/pages/3gps/ > I'm on vacation right now, but I'm pretty sure these were taken > with a 53132A against a good atomic house standard. You'll > see a large phase offset (many microseconds), a frequency > offset (about +3e-12 or -3e-13). No, I didn't remove frequency > drift (if any) from the data before I plotted it. OK. A very quick adaptation using the same program I used for the Febo Cs1/Cs2/Rb data give these runs: Processing vp-1pps.dat Bias report t = 1.608663494e-04 f = 2.770643453e-12 d = -6.750613692e-13 Deviation report tau ADEV drift ADEV drift ADEV drift corr MADEV MADEV drift corr 1 4.496133759e-08 -6.750613692e-13 4.773404719e-13 4.496133759e-08 4.496133759e-08 4.496133759e-08 2 2.865449852e-08 +3.636859572e-14 5.143296131e-14 2.865449852e-08 2.156096803e-08 2.156096803e-08 5 1.023033819e-08 -3.068109484e-13 1.084740511e-12 1.023033814e-08 5.035764941e-09 5.035764883e-09 10 5.467657422e-09 -9.345581882e-15 6.608324323e-14 5.467657422e-09 1.851770267e-09 1.851770292e-09 20 2.739243283e-09 +1.598685109e-14 2.260882162e-13 2.739243274e-09 6.821017995e-10 6.821018772e-10 50 1.093507243e-09 +5.205704132e-15 1.840494346e-13 1.093507227e-09 1.715728448e-10 1.715728594e-10 100 5.454287557e-10 -6.415818074e-16 4.536668467e-14 5.454287538e-10 6.120960706e-11 6.120958759e-11 200 2.703346601e-10 -1.108422405e-16 1.567545998e-14 2.703346596e-10 2.191194834e-11 2.191193475e-11 500 1.093861099e-10 +2.921066096e-17 1.032752822e-14 1.093861094e-10 6.412724502e-12 6.412726902e-12 1000 5.457886650e-11 +1.802704891e-17 1.274704853e-14 5.457886502e-11 2.565426688e-12 2.565390448e-12 2000 2.708262717e-11 -2.666445822e-17 3.770923845e-14 2.708260091e-11 8.491241117e-13 8.457943641e-13 5000 1.095479778e-11 -2.350726513e-17 8.311073291e-14 1.095448251e-11 2.883950982e-13 2.965846010e-13 10000 5.449823758e-12 -2.243416118e-17 1.586334750e-13 5.447514517e-12 3.021670741e-13 1.702555808e-13 20000 2.759576507e-12 -3.330702851e-17 4.710325145e-13 2.719079048e-12 -0.000000000e+00 -0.000000000e+00 Processing cns-1pps.dat Bias report t = 1.600450573e-04 f = 2.913835034e-12 d = 7.500681880e-14 Deviation report tau ADEV drift ADEV drift ADEV drift corr MADEV MADEV drift corr 1 1.577095429e-08 +7.500681880e-14 5.303783021e-14 1.577095429e-08 1.577095429e-08 1.577095429e-08 2 7.681160884e-09 -1.636586807e-13 2.314483259e-13 7.681160881e-09 5.415005871e-09 5.415005862e-09 5 3.078415865e-09 +2.509775393e-14 8.873395999e-14 3.078415864e-09 1.361031473e-09 1.361031473e-09 10 1.560186382e-09 -1.102824139e-14 7.798144274e-14 1.560186380e-09 4.738158072e-10 4.738158043e-10 20 7.798503527e-10 -7.791528277e-15 1.101888496e-13 7.798503449e-10 1.790275974e-10 1.790276051e-10 50 3.127308712e-10 -1.816028065e-15 6.420628798e-14 3.127308646e-10 5.422110976e-11 5.422112463e-11 100 1.584470437e-10 +8.630531074e-17 6.102707048e-15 1.584470436e-10 2.574021466e-11 2.574020071e-11 200 7.909625288e-11 +2.777076930e-16 3.927379858e-14 7.909624313e-11 1.050007533e-11 1.050024793e-11 500 3.205724824e-11 +4.136006326e-17 1.462299060e-14 3.205724491e-11 3.743227983e-12 3.743161194e-12 1000 1.592153776e-11 +8.830182390e-17 6.243881847e-14 1.592141533e-11 1.742977833e-12 1.742820380e-12 2000 8.001780034e-12 +2.310428021e-17 3.267438643e-14 8.001713322e-12 9.412214466e-13 9.412798792e-13 5000 3.255675022e-12 +2.633754927e-17 9.311729843e-14 3.254343101e-12 5.166966738e-13 5.179242182e-13 10000 1.628568806e-12 -3.689307442e-18 2.608734310e-14 1.628359852e-12 2.251512130e-13 2.037213874e-13 20000 7.937637120e-13 -4.168959480e-18 5.895799037e-14 7.915710870e-13 -0.000000000e+00 -0.000000000e+00 Processing cns2-1pps.dat Bias report t = 4.809698766e-06 f = -4.750323886e-13 d = -2.045640513e-14 Deviation report tau ADEV drift ADEV drift ADEV drift corr MADEV MADEV drift corr 1 3.040349710e-09 -2.045640513e-14 1.446486278e-14 3.040349710e-09 3.040349710e-09 3.040349710e-09 2 1.509947204e-09 +5.682593081e-15 8.036400204e-15 1.509947204e-09 1.076505673e-09 1.076505673e-09 5 6.266960438e-10 +4.364826771e-15 1.543199304e-14 6.266960436e-10 2.869965363e-10 2.869965353e-10 10 3.148999828e-10 +9.550229660e-16 6.753032155e-15 3.148999827e-10 1.133942495e-10 1.133942491e-10 20 1.644818676e-10 +2.593384594e-15 3.667599666e-14 1.644818635e-10 6.136054942e-11 6.136054016e-11 50 7.457270904e-11 +1.477060458e-15 5.222197332e-14 7.457269075e-11 3.193493744e-11 3.193493587e-11 100 4.169473933e-11 -2.331156674e-16 1.648376692e-14 4.169473607e-11 1.940095259e-11 1.940091575e-11 200 2.200754349e-11 -1.725996605e-16 2.440927808e-14 2.200752995e-11 9.311192242e-12 9.311282574e-12 500 9.181425432e-12 -6.932415461e-17 2.450978991e-14 9.181392717e-12 3.417399863e-12 3.417697168e-12 1000 4.884844476e-12 +3.584932616e-17 2.534930163e-14 4.884778702e-12 1.648103405e-12 1.648096413e-12 2000 2.481602408e-12 +3.268600930e-17 4.622499765e-14 2.481171852e-12 8.672402194e-13 8.677237253e-13 5000 1.226006674e-12 -3.996599800e-17 1.413011410e-13 1.217836751e-12 5.364543130e-13 5.210280149e-13 10000 5.560201741e-13 +9.211600967e-19 6.513585509e-15 5.559820206e-13 1.500836169e-13 1.448395041e-13 20000 2.290070692e-13 -7.158016508e-18 1.012296403e-13 2.054185914e-13 -0.000000000e+00 -0.000000000e+00 What you will notice here is that for these measures, they are short enought not to be greatly limited by the ADEV drift line. Also notice that I calculate this on a per tau basis, since the effective drift as it bias the ADEV and MDEV calculation is actually calculated as an average and then removed before further accumulation. The MDEV will actually weight certain drift-samples higher than others, but this have not been used, but the ADEV drift estimator was used in its place. The correction for this is however straighforward. Also notice that the ADEV drift-line is calculated out from the drift estimator drift(tau) by multiplying with tau divided by the square root of 2. I also notice that our ADEVs deviate from each other. Hmm. Ah, I must look in your overlapping column! Then they seem to match fairly closly. I only made 1,2,5 steps, but I could to any integer multiple of tau with trivial top-level modification. Cheers, Magnus _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
