HFE/MWR/M1 - Insufficient calibration stability

The noise diode temperature suddenly jumped to > 60 C after a power outage. Following 
additional power problems the noise diode injection temperature drifted fast and the 
radiometer was not able to calibrate properly.

Data during the indicated time periods are poorly calibrated and sometimes erratic. Users 
should be aware that the accuracy of the measurements is dramatically degraded. 

Users can use the microwave profiler (MWRP) data to supplement the MWR data.

• Temperature correction coefficient at 23.8 GHz(tc23)
• MWR column precipitable water vapor(vap)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• Temperature correction coefficient at 31.4 GHz(tc31)
• (tknd)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• Mixer kinetic (physical) temperature(tkxc)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Averaged total liquid water along LOS path(liq)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)

• 31.4 GHz sky brightness temperature derived from tip curve(tbsky31tip)
• Temperature correction coefficient at 31.4 GHz(tc31)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• Noise injection temp at 23.8 GHz derived from this tip(tnd23I)
• Noise injection temp at 31.4 GHz derived from this tip(tnd31I)
• Temperature correction coefficient at 23.8 GHz(tc23)
• 23.8 GHz sky brightness temperature derived from tip curve(tbsky23tip)
• Mixer kinetic (physical) temperature(tkxc)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• (tknd)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• Total liquid water along zenith path using tip-derived brightness temperatures(liqtip)
• Total water vapor along zenith path using tip-derived brightness temperatures(vaptip)

HFE/MWRHF/M1 - 150-GHz data drop out

The sky brightness temperature at 150 GHz (tbsky150) dropped to zero at 12:29 GMT on 
20080804 and stayed flat lined until 23:40 GMT on 20081002.

• Sky brightness temperature (150 GHz)(tbsky150)

HFE/MWRHF/M1 - Calibration updates

The MWRHF calibration algorithm updates the calibration parameters every time a new 
successful tip curve is acquired. 

This results in small jumps (1-2 K) in the brightness temperatures each time calibration 
is updated. During times of frequent calibrations the data appear discontinuous with short 
data segments interrupted by small jumps.

• Sky brightness temperature (90 GHz)(tbsky90)
• Sky brightness temperature (150 GHz)(tbsky150)

HFE/MWRHF/M1 - Elevated noise in 150 GHz data

The noise level of the 150 GHz channel was about 4 times higher than expected, likely due 
to failure of the noise diode.  Disregard the 150 GHz data.

• Sky brightness temperature (150 GHz)(tbsky150)

HFE/MWR/M1 - Missing data

Data are missing and unrecoverable.

• 23.8 GHz Blackbody signal(bb23)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• Time offset of tweaks from base_time(time_offset)
• Mixer kinetic (physical) temperature(tkxc)
• Dummy altitude for Zeb(alt)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• 31.4 GHz blackbody(bb31)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• Temperature correction coefficient at 23.8 GHz(tc23)
• Blackbody kinetic temperature(tkbb)
• 23.8 GHz sky signal(sky23)
• 23.8 GHz blackbody+noise injection signal(bbn23)
• MWR column precipitable water vapor(vap)
• Temperature correction coefficient at 31.4 GHz(tc31)
• (tknd)
• Ambient temperature(tkair)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• 31.4 GHz blac2body+noise injection signal(bbn31)
• lat(lat)
• Averaged total liquid water along LOS path(liq)
• base time(base_time)
• lon(lon)
• 31.4 GHz sky signal(sky31)
• time(time)
• Sky Infra-Red Temperature(sky_ir_temp)

• 31.4 GHz sky signal(tipsky31)
• 23.8 GHz Blackbody signal(bb23)
• base time(base_time)
• Temperature correction coefficient at 31.4 GHz(tc31)
• Noise injection temp at 31.4 GHz derived from this tip(tnd31I)
• Time offset of tweaks from base_time(time_offset)
• lon(lon)
• 31.4 GHz blackbody(bb31)
• 23.8 GHz sky signal(tipsky23)
• 23.8 GHz sky brightness temperature derived from tip curve(tbsky23tip)
• Temperature correction coefficient at 23.8 GHz(tc23)
• Ambient temperature(tkair)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• 31.4 GHz sky brightness temperature derived from tip curve(tbsky31tip)
• 31.4 GHz goodness-of-fit coefficient(r31)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• lat(lat)
• time(time)
• Noise injection temp at 23.8 GHz derived from this tip(tnd23I)
• Actual Azimuth(actaz)
• 31.4 GHz blac2body+noise injection signal(bbn31)
• Dummy altitude for Zeb(alt)
• 23.8 GHz goodness-of-fit coefficient(r23)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• Mixer kinetic (physical) temperature(tkxc)
• Actual elevation angle(actel)
• (tknd)
• Blackbody kinetic temperature(tkbb)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• Total liquid water along zenith path using tip-derived brightness temperatures(liqtip)
• Total water vapor along zenith path using tip-derived brightness temperatures(vaptip)
• 23.8 GHz blackbody+noise injection signal(bbn23)