PDS_VERSION_ID     = PDS3

RECORD_TYPE        = STREAM
OBJECT             = TEXT
  NOTE             = "Known errors and/or anomalies in the volumes"
  PUBLICATION_DATE = 2006-12-21
END_OBJECT         = TEXT
END

ERRORS AND/OR ANOMALIES IN THE CURRENT VOLUME

Volume CORADR_0035, Version 98
------------------------------

1.  The Cassini Radar Transition file (EXTRAS/CRT_035_V01.TAB) contains
no information about ScanStart and ScanEnd transitions.

2.  In the volume index table (INDEX/INDEX.TAB), double quotes enclose
all the date/time values.  Normally, PDS date/time values are not
quoted, but quoting makes parsing easier for some applications.

3.  The HTML documents in the DOCUMENT directory contain HTML character
codes that, while all-ASCII, are not easily interpretable by someone
who is reading the HTML documents as text documents.  For example,
"&#945;" represents the lower-case Greek character "alpha" and is
rendered as such in a web browser.  Equivalent and more legible character
codes (e.g., "&#alpha;") are available as of the HTML 4.0 specification
but cannot be used here, as PDS requires HTML documents to comply to the
HTML 3.2 specification.

4. Antenna temperature, brightness temperature, and receiver temperature are
defined in Janssen, M. A., "An Introduction to the Passive Microwave Remote
Sensing of Atmospheres," Chapter 1 in Atmospheric Remote Sensing by
Microwave Radiometry, (M. Janssen, ed.), pp. 1-35, Wiley & Sons,
New York (1993).  The archived value in the SBDR and LBDR files gives
uncalibrated antenna temperature in units of Kelvin.
It provides calibrated antenna temperature when multiplied by a dimensionless
factor f.  The current best value for f is 0.926.  As this improves it will
change and will likely become a function of time. This value applies also to
all preceeding volumes.

5. Ideally the calibrated antenna temperature is referenced to cold sky at
2.7 K, although no guarantee is made that this zero-level accounting has been
correctly made.  Also, the antenna temperature is not necessarily the
brightness temperature seen in the main beam; e.g., there will be an offset
if the sidelobes happen to fall on other than cold sky.  There are Cassegrain
spillover sidelobes at around 12 degrees from the main beam, and possible
primary spillover lobes in the back direction.  In particular, there is an
offset to be expected and accounted for when an extended source like Titan
or Saturn is observed from close distance.  System gain is the quantity that
multiplies the raw sky counts to convert to the uncalibrated Kelvin scale.
Receiver_temp is the receiver noise temperature Tr (comparison made at
internal reference switch).   The receiver temperature plus the antenna
temperature is equal to the total signal (raw counts times system gain).

6. ant_temp_std is a measure of the rms uncertainty of Ta, and is only an
estimation.  It is obtained as the standard deviation of Ta for three points,
Ta(I-1), Ta(I), and Ta(I+1), and is a useful measure that identifies
questionable data.  For example, it gets large when the beam is sweeping
across a brightness discontinuity.

ERRORS AND/OR ANOMALIES IN PREVIOUS VOLUMES

Not Applicable


