NSA/C1/MWR - liquid water paths affected by frost and ice formation

The heater/blower did not completely remove ice and frost formed on the 
teflon window under severe winter weather conditions. Also, the sensitivity
of the moisture sensor was temperature dependent and, if the temperature 
changd significantly after the sensor had been tuned, the heater failed to 
turn on when the window became wet or frosted. This resulted in unflagged 
periods of elevated and unrealistic values of liquid water path.

The heater/blower assembly was replaced with an improved version that 
incorporates better circuitry, a larger capacity fan, and better airflow 
distribution.

• MWR column precipitable water vapor(vap)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• Averaged total liquid water along LOS path(liq)

NSA/MWR/C1 - software upgrade (version 3.28)

The MWR operating program was upgraded to version 3.28 on 3 February 1999. This version 
includes a beam width correction as well as providing the capability to automatically level 
the elevation mirror (that is, to automatically detect and correct offsets in the 
elevation angle stepper motor position.)

The improvement in the quality of the tip curves resulting from the auto-
leveling has been dramatic: differences in the brightness temperatures at
3 airmasses (19.5 and 160.5 degrees) have been reduced from +/- 5 K to
+/- 0.5 K.  In order to take full advantage of this improvement to detect and reject 
cloudy tip curves, the minimum value of the goodness-of-fit coefficient for a valid tip curve 
has been increased from 0.995 to 0.998.

• MWR column precipitable water vapor(vap)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Averaged total liquid water along LOS path(liq)
• Sky brightness temperature at 23.8 GHz(tbsky23)

• Sky brightness temperature at 23.8 GHz(tbsky23)
• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)
• Sky brightness temperature at 31.4 GHz(tbsky31)