With the release of HWInjReport v 2.2, it was necessary to repeat the prior analysis run spanning the first half of O1, Sep 12 2015 00:00:00 UTC (1126051217) to Oct 23 2015 20:14:43 UTC. In the previous iteration of this run, there were a number of anomalies that necessitation reexamining the logic and implementation of HWInjReport, leading to the creation of version 2.2. While some anomalies, which turned out to not be anomalies, were removed, a few anomalies, which have proven to be true anomalies, still remained, as desired for a properly functioning injection analysis software.

The actual output report, along with the generated log file and the input schedule file containing scheduled injections, have been attached to provide details of output results. Below is a summary analysis of the results.

Parameters

This run was performed with the following parameters:

GPS Start Time = 1126051217 # Beginning of time span, in GPS seconds, to search for injections GPS End Time = 1129666500 # Ending of time span, in GPS seconds, to search for injections Check Hanford IFO = True # Check for injections in the Hanford IFO frame files. Check Livingston IFO = True # Check for injections in the Livingston IFO frame files. IFO Coinc Time = 0.012 # Time window, in seconds, for coincidence between IFO injection events. Check ODC_HOFT = True # Check ODC-MASTER_CHANNEL_OUT_DQ channel in HOFT frames. Check ODC_RAW = True # Check ODC-MASTER_CHANNEL_OUT_DQ channel in RAW frames. Check ODC_RDS = True # Check ODC-MASTER_CHANNEL_OUT_DQ channel in RDS frames. Check GDS_HOFT = True # Check GDS-CALIB_STATE_VECTOR channel in HOFT frames. Check CAL_RAW = True # Check CAL-INJ_ODC_CHANNEL_OUT_DQ channel in RAW frames. Report Normal = True # Include normal (IFO-coincident, consistent, and scheduled for network injections and consistent and scheduled for IFO injections) injections in report Report Anomalous = True # Include anomalous (non-IFO-coincident, inconsistent, or unscheduled) injections in report Use CONDOR optimizations = True # Enable optimizations that assume execution on a CONDOR machine

Scheduled Injections

The schedule file contained some 63 injections. Of these, 43 were found to occur within at least one IFO, and 20 were found to not occur in any IFO. Some of the non-occurring scheduled injections were listed as having zero amplitude scaling; so, it is reasonable that these injection would not be detected as they have no amplitude.

Network and IFO Injections

This run yielded 28 normal network injections, all of which were CBC injections.

There were a significant number of UNSCHEDULED injections, all of which appear to be single-IFO injections.

There were a number of CAL-INJ resets; however, every such reset had the peculiar property that they only show as occurring in only two of the frame channels or bits, with all other channels or bits showing as non-occurring. Further, only specific doublet combinations frame channels/bits occurred in this fashion. These doublet combinations were

• ODC HOFT - GDS HOFT
• CAL-INJ RAW - TRANSIENT bit in CAL-INJ
• ODC RAW - ODC RDS

In other words, for all the report CAL-INJ resets, the frame flags would only show an injection occurring in only one of the above combinations and all other frame flags would show the injection as non-occurring in their associated channel/bit. This phenomenon was verified to occur for several of the CAL-INJ resets; so, report of this phenomenon appears reliable.

There were 3 UNKNOWN injections that occurred only in L1:

• UNKNOWN 1128205784.848 (L1)
• UNKNOWN 1128206748.848 (L1)
• UNKNOWN 1128206957.848 (L1)

These are known hardware injections that were inserted without specifying the type of the injection.

There were several pairs of H1 and L1 single-IFO injections that matched to the same scheduled injection. These are injections that should have been IFO-coincident but had time differences greater than the set IFO coincidence time of 12 ms. These anomalous injections can be seen as occurring together, one after the other, with both being matched to the same scheduled injection. The easiest way to spot this is that a specific Inj UID value will occur twice in immediate succession. In this case, Inj UIDs 29, 30, 31, 38, 40, 48, and 54 occur in this fashion.

It is hypothesized that these anomalies may be due to a known bug that existed at the time in which the amplitude threshold for setting the ODC bits for the occurrence of an injection was not being checked using the absolute value of the output waveform, but instead only checked for positive crossing of the waveform. If waveforms sent to the IFOs are significantly out of phase (such as may occur from one IFO inverting the waveform relative to the other), then, at low frequencies, the ODC bits for one IFO would not register the occurrence of the waveform until significantly after the other IFO. This is because while one IFO outputs a signal crossing into the positive, thus being registered as having an injection at the time of crossing, the other IFO would be outputting a signal crossing into the negative, thus not registering as an injection even though one is occurring. It would not be until the second IFO output a signal crossing into the positive that it would register as having an injection, but this could be significantly outside the 12 ms IFO coincidence window. In fact, one case, Inj UID 31, was found to have a 31 ms (spooky!) difference between start of the injection times for H1 and L1.

It is presumed that corrections have been made to the threshold checks for determining injection occurrence, but I have not, yet, verified that this is the case. It is possible there are other issues that can conspire to evince the above phenomenon.

A follow-on run is currently underway that covers the period from Oct 23 2015 00:00:00 UTC to Nov 17 2015. The intent is to catch-up on missed analysis opportunities due to fixing the software.