What’s in W-band Level 1 Fits Data

(or what I did while in Chile besides shoveling snow and breaking the telescope)

• Telescope pointing Time Ordered 100 Hz Data (TOD)

• House Keeping (voltages, temperatures, pressures, etc…) TOD (1 Hz)

• Clock and Trigger Data (100 Hz)

• Total Power TOD (100 Hz)

• Demodulated TOD (100 Hz)

• Quad TOD (100 Hz)

Data stored in FITS format

Data is stored on Chicago machine: qufs.uchicago.edu

My code: FortranPlotting Routines: Hbook from CERNLIBFFT Code: CERNLIB

My area ~hogann/L1read-fort

I looked at W-band data collected April 2010

This is just the beginning. Did not have time to make all plots.

E2x

Voltage is sampled every 1.25 sec, for a duration of 125 sec.

ADC performs 3 operations every 8000 samples (or 10 msec)

1. 1120 samples out of 8000 samples are IGNORED since they are too near the edges of either the 4 Khz clock, or the 5 Hz clock.

2. An Average (Ex2 + Ey

2)/2 is calculated from the remaining 6880 samples. This is what we call TOTAL POWER DATA

3. An average (Ex2 - Ey

2)/2 is calculated from the remaining 6880 samples. We call this DEMODULATED data, because it takes out the effect of the 4Khz switching.

4. Offline, we can calculate the DOUBLE DEMODULATED (Ex2 - Ey

2)/2, using two successive 10 msec samples.

Arithmetic Operations Done on Q1 Diodes inside the ADC (similar for Q2 diodes)

8000 1.25 sec samples (or 10 msec long)

125 sec.

E2y

125 sec. 125 sec.

125 sec.

250 sec (4 Khz)

Pattern Repeats, except that the 2nd phase switchstate has changed. The 2nd phase switch cycles at the rate of 5 Hz

20 msec long

mill

ivol

tsm

illiv

olts

Behavior of Module 1 Demodulated Diode Output versus Time

pedestal triggers

Correlation between Q1 and Q2, U1 and U2

Diode gainsare NOTequalized

mv2 /

Hz

Telescope Scanning frequency

Single (4Khz) Demodulated Data

mv2 /

Hz

Double (4Khz, 50 Hz) Demodulated Data

mv2 /

Hz

Total Power Data

There’s lots of useful things to look at:

• ADC nonlinearity behavior (B-mode glitching)

• Intensity to Polarization leakage (I-to-Q and I-to-U)

• Noise versus time (effect of clouds)

• Side Lobe

This is a real need for QUIET 1. Not too many peopleare looking at W-band data.