| Subject: | NSA/MWR/C1 - Temperature Stabilization of Noise Diode Impaired |
| DataStreams: | nsa5mwravgC1.c1, nsamwrlosC1.a1, nsamwrlosC1.b1
|
| Description: | On 1/17 we had a big spike in the data and lost temperature stabilization. The instrument
had problems maintaining the Noise Diode (ND) temperature since. At ambient temperatures
under about -20 C the ND was not maintaining the set temperature of 30 C. This problem
was reported in P010122.1.
Fred Solheim recommended on 1/22 that we powercycle the instrument as it looked like the
instrument CPU had lost the temperature reference.
So we powercycled the instrument on 1/22 @ 20:30 and lost all comumnication to it; after a
second powercycling the instrument came back on line and the temperature stabilized
quickly (within a couple of minutes) to the set temperature (30 C)
Fred Solheim reported after the system was restored:
"I've never seen this behavior before. I don't think it was due to the RF deck physically
hanging temperature, because the recorded temp dropped about 30 C in one observation
cycle. If this happens again, send the MWR down along with data files for us to look at."
Data collected in the periode 1/17/2001 6:00 to 1/22/2001 21:45 are questionable since it
is uncertain whether the temperature really was unstable and what really caused the
problem. |
| Measurements: | nsamwrlosC1.a1: - Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
- 23.8 GHz sky signal(sky23)
- IR Brightness Temperature(ir_temp)
- Averaged total liquid water along LOS path(liq)
- Sky brightness temperature at 23.8 GHz(tbsky23)
- (tknd)
- Water on Teflon window (1=WET, 0=DRY)(wet_window)
- Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
- 31.4 GHz blac2body+noise injection signal(bbn31)
- Temperature correction coefficient at 23.8 GHz(tc23)
- 31.4 GHz sky signal(sky31)
- Temperature correction coefficient at 31.4 GHz(tc31)
- Ambient temperature(tkair)
- 31.4 GHz blackbody(bb31)
- Blackbody kinetic temperature(tkbb)
- Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
- MWR column precipitable water vapor(vap)
- 23.8 GHz blackbody+noise injection signal(bbn23)
- Sky brightness temperature at 31.4 GHz(tbsky31)
- Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
- Mixer kinetic (physical) temperature(tkxc)
- 23.8 GHz Blackbody signal(bb23)
nsa5mwravgC1.c1: - Sky brightness temperature at 23.8 GHz(tbsky23)
- Standard deviation about the mean for the IR brightness temperature(ir_temp_sdev)
- Number of points included in the ir_temp ensemble(num_obs_irt)
- Standard deviation about the mean for the 23.8 GHz sky brightness temperature(tbsky23_sdev)
- Fraction of data in averaging interval with water on Teflon window(water_flag_fraction)
- IR Brightness Temperature(ir_temp)
- Standard deviation about the mean for the 31.4 GHz sky brightness temperature(tbsky31_sdev)
- Standard deviation about the mean for the total liquid water amount(liq_sdev)
- Number of data points averaged for 23tbsky, 31tbsky, vap & liq(num_obs)
- Sky brightness temperature at 31.4 GHz(tbsky31)
- MWR column precipitable water vapor(vap)
- Averaged total liquid water along LOS path(liq)
- Standard deviation about the mean for the total water vapor amount(vap_sdev)
nsamwrlosC1.b1: - MWR column precipitable water vapor(vap)
- Water on Teflon window (1=WET, 0=DRY)(wet_window)
- Averaged total liquid water along LOS path(liq)
- Sky brightness temperature at 31.4 GHz(tbsky31)
- IR Brightness Temperature(ir_temp)
- Sky brightness temperature at 23.8 GHz(tbsky23)
|