SGP/MWR/B6 - High noise level, poor calibration

The data from this instrument (serial number 18) have become increasingly noisy, most 
likely due to a failing local oscillator.  A consequence of this increased noise level has 
been few valid calibration scans ("tip curves") since 1 April 2002: during the period 26-31 
March 2002 1496 valid tip curves were acquired, whereas only 729 were acquired during 
April, 387 during May, 143 during June, 243 during July.  As a result, the calibration was 
not as well-maintained as usual.  The measured brightness temperatures and retrieved 
precipitable water vapor and liquid water path should be regarded as suspect.  The instrument 
was replaced with serial number 04 on 2 August 2002.

null

• 23.8 GHz Blackbody signal(23bb)
• 23.8 GHz sky brightness temperature(23tbsky)
• 31.4 GHz sky brightness temperature(31tbsky)
• 31.4 GHz noise injection brightness temperature(31unoise)
• 31.4 GHz blackbody+noise injection signal(31bbn)
• Averaged total liquid water along LOS path(liq)
• 31.4 GHz sky signal(31sky)
• 23.8 GHz sky signal(sky23)
• Temperature correction coefficient at 23.8 GHz(temperature_correction_coef_23)
• Mean 23.8 GHz sky brightness temperature(tbsky23)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• 23.8 GHz sky+noise injection signal(23skyn)
• 23.8 GHz blackbody+noise injection signal(bbn23)
• Temperature correction coefficient at 31.4 GHz(temperature_correction_coef_31)
• Total water vapor along LOS path(vap)
• 23.8 GHz sky signal(23sky)
• 23.8 GHz noise injection brightness temperature(23unoise)
• Noise injection temp at nominal temperature at 31.4 GHz(noise_injection_temp_31)
• 23.8 GHz blackbody+noise injection signal(23bbn)
• 31.4 GHz blac2body+noise injection signal(bbn31)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• 31.4 GHz blackbody(bb31)
• Noise injection temp at nominal temperature at 23.8 GHz(noise_injection_temp_23)
• 31.4 GHz blackbody(31bb)
• 31.4 GHz sky+noise injection signal(31skyn)
• 23.8 GHz Blackbody signal(bb23)
• Mean 31.4 GHz sky brightness temperature(tbsky31)
• 31.4 GHz sky signal(sky31)

• 23.8 GHz blackbody+noise injection signal(bbn23)
• 31.4 GHz sky signal(sky31)
• Temperature correction coefficient at 31.4 GHz(tc31)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• Total water vapor along LOS path(vap)
• 31.4 GHz blackbody(bb31)
• 23.8 GHz sky signal(sky23)
• 31.4 GHz blac2body+noise injection signal(bbn31)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• Mean 31.4 GHz sky brightness temperature(tbsky31)
• Averaged total liquid water along LOS path(liq)
• Mean 23.8 GHz sky brightness temperature(tbsky23)
• 23.8 GHz Blackbody signal(bb23)
• Temperature correction coefficient at 23.8 GHz(tc23)

• Averaged total liquid water along LOS path(liq)
• Temperature correction coefficient at 23.8 GHz(tc23)
• 23.8 GHz blackbody+noise injection signal(bbn23)
• 31.4 GHz sky signal(sky31)
• 23.8 GHz Blackbody signal(bb23)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• Total water vapor along LOS path(vap)
• Mean 31.4 GHz sky brightness temperature(tbsky31)
• 31.4 GHz sky brightness temperature(31tbsky)
• Mean 23.8 GHz sky brightness temperature(tbsky23)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• Temperature correction coefficient at 31.4 GHz(tc31)
• 31.4 GHz blackbody(bb31)
• 23.8 GHz sky signal(sky23)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• 23.8 GHz sky brightness temperature(23tbsky)
• 31.4 GHz blac2body+noise injection signal(bbn31)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)