Appendix E
Engineering Snapshots

Certain engineering parameters from the instruments, such as detector temperatures and voltages, were identified before launch as being necessary to process and calibrate science data. Engineering snapshots were, therefore, obtained at the beginning of an exposure and every 5 minutes thereafter, with a final one taken at the end of the exposure (Section 5.3). A brief description of the content of snapshot files is given below. More details can be found in the Instrument Handbook (2009).

Table E.1: Formats of snap/snpaf/snpbf Files^a

Array Name	Format	Description
HDU 1: Empty (Header only)
HDU 2: Time ordered data
I_UT_TIME_MJD	double	Snapshot time in MJD (days)
I_DET1ELTEMP	double	DET1 electronics temperature
I_DET1PLTEMP	double	DET1 Baseplate temperature
I_DET2ELTEMP	double	DET2 electronics temperature
I_DET2PLTEMP	double	DET2 Baseplate temperature
I_DET1XSCALEAST	double	DET1 segment A Time (X) image scale factor.
I_DET1XOFFSETAST	double	DET1 segment A Time (X) image postion offset.
I_DET1XSCALEBST	double	DET1 segment B Time (X) image scale factor.
I_DET1XOFFSETBST	double	DET1 segment B Time (X) image postion offset.
I_DET2XSCALEAST	double	DET2 segment A Time (X) image scale factor.
I_DET2XOFFSETAST	double	DET2 segment A Time (X) image postion offset.
I_DET2XSCALEBST	double	DET2 segment B Time (X) image scale factor.
I_DET2XOFFSETBST	double	DET2 segment B Time (X) image postion offset.
I_DET1TEMP	double	DET1 Detector temperature.
I_DET1HVMODLTEMP	double	DET1 High Voltage Module temperature.
I_DET1HVFLTRTEMP	double	DET1 High Voltage Filter temperature.
I_DET1AMPBTEMP	double	DET1 segment B Amplifier temperature.
I_DET1AMPATEMP	double	DET1 segment A Amplifier temperature.

Table E.2: Table E.1 (continued)^a

Array Name	Format	Description
I_DET1TDCBTEMP	double	DET1 TDC B temperature.
I_DET1TDCATEMP	double	DET1 TDC A temperature.
I_DET1MCPBBIASCUR	double	DET1 MCP B Bias Current
I_DET1MCPABIASCUR	double	DET1 MCP A Bias Current
I_DET1HVBIASBST	double	DET1 MCP-B High Voltage Bias setting
I_DET1HVBIASAST	double	DET1 MCP-A High Voltage Bias setting
I_DET1UPRQTHRBST	double	DET1 TDC-B Upper Charge Threshold setting.
I_DET1UPRQTHRAST	double	DET1 TDC-A Upper Charge Threshold setting.
I_DET1BEGWLKBST	double	DET1 TDC-B Begin CFD Walk setting.
I_DET1BEGWLKAST	double	DET1 TDC-A Begin CFD Walk setting.
I_DET1ENDWLKBST	double	DET1 TDC-B End CFD Walk setting.
I_DET1ENDWLKAST	double	DET1 TDC-A End CFD Walk setting.
I_DET1BSLTHRBST	double	DET1 TDC-B charge Baseline inspector window Thr
I_DET1BSLTHRAST	double	DET1 TDC-A charge Baseline inspector window Thr
I_DET1LWRQTHRBST	double	DET1 TDC-B Lower Charge Threshold setting.
I_DET1LWRQTHRAST	double	DET1 TDC-A Lower Charge Threshold setting.
I_DET1LWRTTHRBST	double	DET1 TDC-B Lower Time Threshold setting.
I_DET1LWRTTHRAST	double	DET1 TDC-A Lower Time Threshold setting.
I_DET1HVGRIDST	integer	DET1 Grid High Voltage Status (0=OFF; 1=ON)
I_DET1HVPWRST	integer	DET1 Bias High Voltage Status (0=OFF; 1=ON)
I_DET1STIMLMPST	integer	DET1 Stimulation Lamp Status (0=OFF; 1=ON)
I_DET2TEMP	double	DET2 Detector temperature.
I_DET2HVMODLTEMP	double	DET2 High Voltage Module temperature.
I_DET2HVFLTRTEMP	double	DET2 High Voltage Filter temperature.
I_DET2AMPBTEMP	double	DET2 segment B Amplifier temperature.
I_DET2AMPATEMP	double	DET2 segment A Amplifier temperature.
I_DET2TDCBTEMP	double	DET2 TDC B temperature.
I_DET2TDCATEMP	double	DET2 TDC A temperature.
I_DET2MCPBBIASCUR	double	DET2 MCP B Bias Current
I_DET2MCPABIASCUR	double	DET2 MCP A Bias Current
I_DET2HVBIASBST	double	DET2 MCP-B High Voltage Bias setting
I_DET2HVBIASAST	double	DET2 MCP-A High Voltage Bias setting
I_DET2UPRQTHRBST	double	DET2 TDC-B Upper Charge Threshold setting.
I_DET2UPRQTHRAST	double	DET2 TDC-A Upper Charge Threshold setting.
I_DET2BEGWLKBST	double	DET2 TDC-B Begin CFD Walk setting.
I_DET2BEGWLKAST	double	DET2 TDC-A Begin CFD Walk setting.
I_DET2ENDWLKBST	double	DET2 TDC-B End CFD Walk setting.
I_DET2ENDWLKAST	double	DET2 TDC-A End CFD Walk setting.
I_DET2BSLTHRBST	double	DET2 TDC-B charge Baseline inspector window Thr
I_DET2BSLTHRAST	double	DET2 TDC-A charge Baseline inspector window Thr

Table E.3: Table E.1 (continued)^a

Array Name	Format	Description
I_DET2LWRQTHRBST	double	DET2 TDC-B Lower Charge Threshold setting.
I_DET2LWRQTHRAST	double	DET2 TDC-A Lower Charge Threshold setting.
I_DET2LWRTTHRBST	double	DET2 TDC-B Lower Time Threshold setting.
I_DET2LWRTTHRAST	double	DET2 TDC-A Lower Time Threshold setting.
I_DET2HVGRIDST	integer	DET2 Grid High Voltage Status (0=OFF; 1=ON)
I_DET2HVPWRST	integer	DET2 Bias High Voltage Status (0=OFF; 1=ON)
I_DET2STIMLMPST	integer	DET2 Stimulation Lamp Status (0=OFF; 1=ON)
I_FPD_Q_ECIBDY1	double	ECI to body quaternion 1
I_FPD_Q_ECIBDY2	double	ECI to body quaternion 2
I_FPD_Q_ECIBDY3	double	ECI to body quaternion 3
I_FPD_Q_ECIBDY4	double	ECI to body quaternion 4
aAll Temperatures are in Degrees, currents in Amps.