PDS_VERSION_ID        = PDS3
RECORD_TYPE           = STREAM

OBJECT                = TEXT
  PUBLICATION_DATE    = 2012-07-05
  NOTE                = "Description of contents of CALIB directory"
END_OBJECT            = TEXT
END

The CALIB directory contains the following files.

SAM_HK_CONVERSIONS.CSV - Conversion factors for science and engineering units.

This file contains conversions for converting raw SAM telemetry values
(e.g., the housekeeping data represented in this archive as "level 0"
data) to dimensional quantities with standard scientific units (e.g.,
the housekeeping data represented in this archive as "level 1a"). Note
that housekeeping values that have no conversions defined are not
represented in level 1a of the archive.

For at least some housekeeping values, there is an intermediate value
known as the "engineering" value, corresponding to a voltage read by a
analog-to-digital converter. This value is used internally by SAM
engineers and is not important to the final interpretation of SAM
housekeeping data, since most housekeeping fields are decidedly not
voltages. The engineering value does not appear anywhere in the archive,
but the voltage value is often used as an input to the scientific
conversion.

For each housekeeping field denoted by the first column, the value of
the next column selects one of several equations for converting raw
units to engineering units. The two following columns contain constants
K1 and K2, which are used as parameters in the selected equation.

The next column selects one of several equations for converting raw
units to scientific units, or engineering units to scientific units,
depending on the equation. The next eight columns describe constants K1
through K5, which are used as parameters in the selected equation.

In all of the following, let R represent the raw value, E represent
the engineering value, and S represent the science value.

Equation 0 -- No Conversion
=============================
This may be used as either an engineering equation or a scientific
equation. If used as an engineering equation, then no engineering
conversion is defined and the engineering value is equal to the raw
value. If used as a scientific equation, then no further scientific
conversion is defined and the scientific value is equal to the
engineering value.

E = R
S = E


Equation 1 -- Polynomial Conversion
===================================
This may be used as either an engineering equation or a scientific
equation. It is a polynomial equation, where K1 represents the constant
factor, K2 represents the linear factor, K3 the quadratic factor, and
so forth. Since engineering values only define K1 and K2, a polynomial
engineering conversion can be at most linear. If used as a scientific
equation, then it uses the engineering value as the variable factor of
the polynomial.

E = K1 + K2 * R
S = K1 + K2 * E + K3 * E^2 + K4 * E^3 + K5 * E^4


Equation 2 -- Analog-to-Digital Converter to Volts
==================================================
This may be used only as an engineering equation. It represents a very
common conversion for SAM's two-byte ADCs.

E = K1 * (K2 * (R - 32768)) / 65536


Equation 4 -- Thermistor
========================
This may be used only as a scientific equation. It is used to calculate
temperature from a raw thermistor value. The engineering value is not
used.

Let Resistance = K2 * (R – K1) / (65536 – R)
S = 1 / (K3 + K4 * ln(Resistance) + K5 * (ln(Resistance))^3) - 273.13


Equation 6 -- Platinum Resistance Thermometer
=============================================
This may be used only as a scientific equation. It is used to calculate
a temperature from the raw ADC readings of a platinum resistance
thermometer. The engineering value is not used. This equation requires
solving a quadratic equation for S. Since there are two solutions, the
preferred solution will be the one closer to the solution obtained by
ignoring the quadratic coefficient K3.

R = K1 + K2 * S + K3 * S^2 (prefer closest solution to -K1 / K2 for S)


Equation 8 -- Thermistor from Engineering
=========================================
This may be used only as a scientific equation. It is used to calculate
a temperature from an engineering value (not the raw value).

Let Resistance = K2 * (E + K1) / (10 - K1)
S = 1 / (K3 + K4 * ln(Resistance) + K5 * (ln(Resistance))^3) - 273.13