PDS_VERSION_ID     = PDS3
RELEASE_ID         = 0001
REVISION_ID        = 0000
RECORD_TYPE        = STREAM
OBJECT             = TEXT
  PUBLICATION_DATE = 2003-06-15
  NOTE             = "Description of calibration files included in CALIB
directory"
END_OBJECT
END

CALIB directory of SPEDE PDS archive
======================================

CALIB directory contains calibration files for SPEDE instrument.

Langmuir measurements are calibrated to physical values (Amperes)
with the following polynomial:

I(V(b)) = a3*f(b)^3 + a2*f(b)^2 + a1*f(b) + a0, where

f(b) = Background(b) - raw measurement(b), b = bias, f = frequency (Hz)

SPEDE_BIAS_CALIB.TAB contains a look-up table for bias physical values (Volts),
and background values for each bias. The values are given separately for
both -X and +X probes.

SPEDE_CURRENT_CALIB.TAB contains polynomial coefficients for the calibration
polynomial given above.