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PTI V2 Data Products

Summary (.sum) File Description

Summary files are ASCII text files that contain the wide-bandL-1 V2 data for PTI. The following gives an example of aline from a PTI summary file:
SUM: 05/18/99 HDC118216    4.610069  -26.4356700   623.5  0.368  0.357    39.1  0.457  0.500  0.52   1.08   1.08    71.7   705.2   465.5   80.6    117.8  104.2  2.191   0.98   1  0  OK 13.57994652 37.18241501 100

The line consists of a number of space-delimited fields. Themeanings of these fields are summarized in the table below. Each linecorresponds to a block average of typically 25 seconds of fringedata, not necessarily contiguous. All entries, including time anddelay line position, are mean values for the block.

field#

content

comments
1

SUM:

a literal string; each line starts with SUM to support the grep extraction mechanism from the intermediate .data file produced by vis.
2

date

UTC date of the observation (mm/dd/yyyy)
3

target

Target designation (ASCII string)
4

time

Mean observation time (decimal UTC hours)
5

DL position

Mean delay line position (m)
6

white light (wide-band) photon count

DN units (approximately 5 photons/DN)
7

incoherent white light V2

Wide-band (dimensionless)
8

coherent white light V2

Wide-band (dimensionless)
9

spectrometer photon count

DN units (approximately 5 photons/DN); SNR-weighted average over spectrometer channels
10

coherent spec V2

Coherent averaged synthetic wide-band V2; SNR-weighted average over spectrometer channels (dimensionless)
11

incoherent spec V2

Incoherent averaged synthetic wide-band V2; SNR-weighted average over spectrometer channels (dimensionless)
12

phase jitter

rms phase difference between consecutive fringe frames (radians)
13

ratio correction for coherent spectrometer visibility

Visibility correction due to arm intensity mismatch (dimensionless)
14

ratio correction for incoherent spectrometer visibility

Visibility correction due to arm intensity mismatch (dimensionless)
15

background white light photon count

Wide-band dark measurement (measured with both siderostats pointing off-target) (DN units)
16

foreground white light photon count

Wide-band two-arm intensity measurement (measured with both siderostats pointing on target, with delay offset from zero-OPD, to get total flux) (DN units)
17

ratio white light photon count

Wide-band single-arm intensity measurement (measured with one arm blocked to get single-arm flux) (DN units)
18

background spectrometer photon count

Specrometer dark measurement (measured with both siderostats pointing off-target) (DN units)
19

foreground spectrometer photon count

Spectrometer two-arm intensity measurement (measured with both siderostats pointing on target, with delay offset from zero-OPD, to get total flux) (DN units)
20

ratio spectrometer photon count

Spectrometer single-arm intensity measurement (measured with one arm blocked to get single-arm flux) (DN units)
21

wavelength of the observation

SNR-weighted effective wavelength of the synthetic wide-band V2 (microns)
22

fracTime

The ratio of the seconds of fringe data to the length of the block required to collect that much data. (dimensionless) (If FT continuously locked this value is 1.0)
23

number of fringe locks

 
24

calibration warning flag

numeric value; indicates possible non-coincidence of calibrations with fringe data
25

calibration warning flag

text description of the flag

value

name

meaning
0
OK

no problem detected
1
FG_RT

time between foreground and ratio measurement, normally consecutive, exceeded threshold
2
RT_FR

time between ratio measurement and start of fringe data exceeded threshold
3
FR_BG

time between fringe data and background measurement exceeded threshold

26

target RA

Target RA (J2000) (decimal hours)
27

target decl.

Target declination (J2000) (decimal degrees)
28

frame rate

Fringe frame rate (Hz)
29

X quadrature

Fringe X quadrature (DN)
30

Y quadrature

Fringe Y quadrature (DN)
31

Baseline

PTI baseline name