Calibration Analysis Notes

Notes and Problems from Calibration Analysis

CASY 1996, 051

  1. Random noise cal did not work.
  2. Early set of cals (before the random noise cal) are about the same size as the "good" cals, but the signal on the data is much larger. Engineer (Lawrence) confirms feedback box settings were wrong for these "early" cals.

CCM 1996, 018

  1. SP cals only. Cals are not in archive. No data after ~ 1996,018:21.

HKT 1995, 205

  1. Only step cals (and these were run too small).

KIEV 1995, 031

  1. Cals are there, but cal input channels stop prematurely (and don't contain any signal anyway).

KIP 1995, 212-213

  1. Data not present for VSP cals.

LSZ 1994, 220

  1. Most recordings of the cal input channels (BCZ, BCN, and BCE) are fragmentary and incomplete.

MA2 1995, 251

  1. Why only sinusoids at three frequencies?

SDV 1994, 231

  1. Cal input channels stop prematurely (or are non-existant) for some of the cals.
  2. Random noise cal did not work -- it looks like a step cal.
  3. Fits to most of the sine cals are poor.

SJG 1995, 240-241

  1. No recording of cal input channels.

TIXI 1995, 227

  1. Z step cal polarity is at odds with the N-S and E-W polarities -- possible incorrect polarity on one or more channels?

TSUM 1995, 317-318

  1. Random noise cal looks like a series of very long step cals.
  2. There are some problems with the 1000 s sinusoid cal -- the time alignment of, for example, BHZ and BCI is very poor. Possibly the entire BCI recording of the 1000 s cal is somehow erroneous?

YAK 1995, 236

  1. Only step cals were done. The Z cal seems also to be on the N-S, but with opposite polarity.
  2. The true N-S cal has the same polarity as the Z cal.
  3. The E-W cal seems to have been done on the Z and not on the E-W.

YSS 1995, 215-216

  1. There are some problems with the 1000 s sinusoid cal -- the time alignment of, for example, BHZ and BCZ is very poor.
  2. Scale factors for the various sine cals look very bad. Although the variance reductions are not great, they are sufficient for the scale factors to be roughly correct. It looks like the feedback box settings for the calibration circuit could be wrong (wrong resistors or capacitance cal?).