PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT NOTE = "Known errors and/or anomalies in the volumes" PUBLICATION_DATE = 2006-12-20 END_OBJECT = TEXT END ERRORS AND/OR ANOMALIES IN THE CURRENT VOLUME Volume CORADR_0074, Version 01 ------------------------------ 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, "α" 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