Results of LLNL investigation of NYCT data sets Page: 3 of 13
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Lawrence Livermore National Laboratory
August 3, 2007
Upon examination we have concluded that none of the alarms indicate the presence of a real
A brief history and results from our examination of the NYCT ASP occupancy data sets dated
from 2007-05-14 19:11:07 to 2007-06-20 15:46:15 are presented in this letter report.
When the ASP data collection campaign at NYCT was completed, rather than being shut down,
the Canberra ASP annunciator box was unplugged leaving the data acquisition system running.
By the time it was discovered that the ASP was still acquiring data about 15,000 occupancies had
been recorded. Among these were about 500 alarms (classified by the ASP analysis system as
either Threat Alarms or Suspect Alarms). At your request, these alarms have been investigated.
Our conclusion is that none of the alarm data sets indicate the presence of a real threat (within
The data sets (ICD1 and ICD2 files with concurrent JPEG pictures) were delivered to LLNL on a
removable hard drive labeled FOUO. The contents of the data disk amounted to 53.39 GB of
data requiring over two days for the standard LLNL virus checking software to scan before work
could really get started. Our first step was to walk through the directory structure of the disk and
create a database of occupancies. For each occupancy, the database was populated with the
occupancy date and time, occupancy number, file path to the ICD1 data and the alarm ("No
Alarm", "Suspect Alarm" or "Threat Alarm") from the ICD2 file along with some other
In an attempt to get a global understanding of what was going on, we investigated the occupancy
information. The occupancy date/time and alarm type were binned into one-hour counts. These
data are shown in Figures 1 and 2.
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Sale, K; Harrison, M; Guo, M & Groza, M. Results of LLNL investigation of NYCT data sets, report, August 1, 2007; Livermore, California. (digital.library.unt.edu/ark:/67531/metadc901522/m1/3/: accessed September 25, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.