Viking Lander Labeled Release Dataset release notes

This file contains release notes and errata concerning the Viking Lander Labeled
Release archive. It includes information from the errata.txt file in PDS3
version of the dataset.

Most of the documentation included in the PDS4 bundle is derived from the PDS3
catalog files and the volinfo.txt file. There are separate spacecraft host
documents. But these documents are basically the same because the two landers
were identical. Likewise, the two Labeled Release instruments are basically the
same and the documents that describe them are the same. The separate documents
for the spacecraft and instruments are maintained in this PDS4 archive because
the PDS4 system has separate LIDs for those objects.


Comments From the PDS3 Labeled Release Archive

1.  Anomalous Values

    The LR radioactivity and temperature measurements occasionally contain
anomalous values. These values were defined as being more than 4 standard
deviations different from the local mean value. These anomalous values are
typically isolated spikes in the data. According to the PI and CO-I, the
anomalous values are most likely related to other events occurring on the
spacecraft and are not errors caused by data transmission to Earth. The
anomalous values are tagged in the radioactivity and temperature data files.

2.  Single to Dual Channel Counting Transitions

     The first portion of Viking Lander 2 cycle 3 used single channel counting
for radioactivity measurements. This mode was used because the investigators
were concerned about the health of the LR beta particle counters. Single channel
count data were corrected to the equivalent dual channel values by multipling by
a constant. There are several times when the counting mode switched during the
cycle. The switch did not always occur on a counting period boundary. Thus, a
counting period that spanned the time of a switch consists of a combination of
single and dual counting. These time periods are tagged in the radioactivity
data files because the values are not valid.

3.  Revised Two Data Files (2006-10-12)

     A user reported errors in a few records in two of the data files. These
records have been corrected. The affected files are VL1C3HT.TAB and VL2C1DT.TAB.