To attempt to debug the 2Hz noise seen on the kryptons during this project, I have set up part of stn #4 in the lab:
DSM #5
CSAT #0671
GPS for timekeeping
First, I used KH2O #1133 and saw no noise on an output voltage of about 0.21V. I blocked the optical path and saw no noise at 0.00V.
Next, I swapped in KH2O #1394 (the actual krypton used at stn #4. It now outputs 1.43V, but also had no noise. Also no noise when blocked and reading 0.00V.
Next, I added the cradlepoint with a modem back into the DSM. The modem wasn't connected (due to placement in the room), so no data transfer was occurring. Still no noise.
That's it for now. Next steps would be:
- Move to get cell coverage
- Add 2 TRHs
- Add barometer & prop
- Add solar panels
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Round 2, 9/19:
Tripod set up outside near basketball court (mostly the same)
- DSM5, CSAT0671, back to KH2O1133 (since I didn't want to risk putting 1394 outside before post-cals), GPS
- Modem on using Cradlepoint, transmitting UDP data to rt-server.eol (sp?)
- Power from solar panels
Ambient kh2ov = 0.34V. Thought I saw some noise during one "kv", but couldn't replicate it. Bagged detector, so 0.00V and no noise.
Final step is to add the remaining 4 sensors (2xTRH, prop, baro).
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Round 3, 9/28:
Added TRH, Baro, Prop, Power mote to tripod set-up. All the same S/N as used at #4, except possibly not mote (or TRH fan)
- Some jumping, but doesn't analyze as clear 2Hz with ambient voltage ~0.38V
- Put bag back on, get 0.00V, no noise evident (spectra show a slight bump at 5Hz -- probably A/D conversion artifact)
- Replaced bag by bit of wire mesh, reduced voltage to 0.18V. Also changed mote power switch, which might have been off.
Not seeing noise here either (or data from the mote, for that matter).
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Interlude: look at snapshots of data from other projects:
TREX: Don't see 2Hz noise for a case when V~0.6V at night (though white digitizing noise is obvious). Noise level is much lower than seen in CWEX (so CWEX noise would show up).
dpar(start="2006 mar 30 04:00",lenmin=30)
iod = prep("kh2oV.30m#3")
PCAPS: Also no 2Hz noise for a case with V~0.6V at night. Similar comments as above.
dpar(start="2011 jan 4 4:30",lenmin=30)
iod = prep("kh2oV#7")