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/MPL/M1 - Frosting/Condensation

On various days during the China deployment, condensation accumulated on the view port 
window of the MPL and compromised its capability to detect clouds.  This problem most often 
occurred during nighttime hours from May through early September.  

During the listed times, cloud retrievals and aerosol profiles should be considered 
doubtful or in error.

The dates/times of occurrence are:
16:00-23:59 GMT on 05/18
17:00-22:00 GMT on 05/23
20:00-22:00 GMT on 05/25
15:00-23:59 GMT on 06/07
17:00-23:59 GMT on 06/08
15:00-23:00 GMT on 06/09
14:00-18:00 GMT on 06/18
18:00-21:00 GMT on 06/21
14:00-16:00 GMT on 06/23
16:00-21:00 GMT on 06/27
17:00-20:00 GMT on 06/28
      22:00 GMT on 06/29
19:00-23:00 GMT on 06/30
13:30-22:30 GMT on 07/02
16:00-17:30 GMT on 07/03 
20:30-22:00 GMT on 07/03
21:30-22:30 GMT on 07/05
13:00-22:00 GMT on 07/06
17:00-18:00 GMT on 07/07
21:00-22:30 GMT on 07/07
16:00-23:59 GMT on 07/10
11:00-23:00 GMT on 07/11
18:00-23:00 GMT on 07/12
15:00-16:00 GMT on 07/13
18:00-23:59 GMT on 07/14
18:00-21:00 GMT on 07/15
17:30-23:00 GMT on 07/16
17:00-23:00 GMT on 07/17
13:00-23:30 GMT on 07/20
18:00-23:00 GMT on 07/24
21:00-23:00 GMT on 07/25
21:00-22:30 GMT on 07/27
12:00-23:59 GMT on 08/02
16:00-21:30 GMT on 08/03
16:00-23:00 GMT on 08/04
14:00-22:30 GMT on 08/05
19:00-23:00 GMT on 08/07
19:00-21:30 GMT on 08/08
15:00-23:30 GMT on 08/10
17:30-23:30 GMT on 08/12
14:00-15:00 GMT on 08/14
16:30-22:30 GMT on 08/14
21:30-22:30 GMT on 08/17
12:00-23:59 GMT on 08/18
12:00-13:30 GMT on 08/19
20:00-23:30 GMT on 08/19
15:00-23:59 GMT on 08/20
11:00-23:59 GMT on 08/22
11:00-23:30 GMT on 08/23
12:00-23:30 GMT on 08/25
13:00-23:30 GMT on 08/26
16:30-23:59 GMT on 08/27
17:00-23:00 GMT on 08/31
15:00-23:59 GMT on 09/01
15:00-20:00 GMT on 09/02
19:30-23:59 GMT on 09/05
16:30-22:30 GMT on 09/09
19:30-23:59 GMT on 09/12
20:30-23:59 GMT on 09/15
14:00-16:30 GMT on 09/16
19:00-23:59 GMT on 09/16
20:30-23:59 GMT on 10/29
22:00-23:59 GMT on 11/01
20:00-23:59 GMT on 11/23
00:00-02:00 GMT on 11/24

• lon(lon)
• *(aqc_signal_return_cross_pol)
• Detector Temperature(detector_temp)
• Background signal standard deviation, cross-pol(background_signal_std_cross_pol)
• Dead time correction flag(dead_time_corrected)
• Dummy altitude for Zeb(alt)
• Repetition Rate, or Trigger Frequency of the laser(pulse_rep)
• effective range offset due to poor sync between laser firing and A/D trigger.(range_offset)
• *(aqc_signal_return_co_pol)
• range(range)
• Number of samples used for cross-pol averages(nsamples_cross_pol_average)
• Number of detector channels(num_channels)
• Distance from leading edge of first range bin to the center of each bin .(range_bins)
• Laser output energy per pulse(energy_monitor)
• lat(lat)
• Number of bins stored in data block(num_bins)
• base time(base_time)
• Background signal, co-pol(background_signal_co_pol)
• Preliminary cloud base height above ground level, co-pol(preliminary_cbh_co_pol)
• Polarization control voltage, cross-pol(polarization_control_voltage_cross_pol)
• Number of samples used for co-pol averages(nsamples_co_pol_average)
• Telescope temperature(scope_temp)
• Background signal standard deviation, co-pol(background_signal_std_co_pol)
• Attenuated backscatter, cross-pol(signal_return_cross_pol)
• Number of laser pulses summed during averaging interval(shots_per_sample)
• Background signal, cross-pol(background_signal_cross_pol)
• Time offset of tweaks from base_time(time_offset)
• Array of heights for the range gates(height)
• Polarization control voltage, co-pol(polarization_control_voltage_co_pol)
• Width of range-bins calculated from range_bin_time(range_bin_width)
• Preliminary cloud base height above ground level, cross-pol(preliminary_cbh_cross_pol)
• Attenuated backscatter, co-pol(signal_return_co_pol)
• time(time)
• Maximum altitude retrieved from multichannel scalar card.(max_altitude)
• Laser Temperature(laser_temp)

• Preliminary cloud base height(preliminary_cbh)
• Width of range-bins calculated from range_bin_time(range_bin_width)
• Polarization control enabled flag(polarization_control)
• lat(lat)
• effective range offset due to poor sync between laser firing and A/D trigger.(range_offset)
• Attenuated backscatter(signal_return)
• Number of laser pulses summed during averaging interval(shots_per_avg)
• Laser Temperature(laser_temp)
• base time(base_time)
• Number of bins stored in data block(num_bins)
• Maximum altitude retrieved from multichannel scalar card.(max_altitude)
• Dummy altitude for Zeb(alt)
• Array of heights for the range gates(height)
• Background signal standard deviation(background_signal_std)
• Repetition Rate, or Trigger Frequency of the laser(pulse_rep)
• Number of detector channels(num_channels)
• lon(lon)
• Background Signal(background_signal)
• Polarization control voltage setting(polarization_control_voltage)
• Telescope temperature(scope_temp)
• Detector Temperature(detector_temp)
• Dead time correction flag(dead_time_corrected)
• range(range)
• Time offset of tweaks from base_time(time_offset)
• Distance from leading edge of first range bin to the center of each bin .(range_bins)
• time(time)
• Time in nanoseconds for each range bin of multichannel scalar card.(range_bin_time)
• Laser output energy per pulse(energy_monitor)

• lat(lat)
• base time(base_time)
• Background signal, co-pol(background_signal_co_pol)
• Laser Temperature(laser_temp)
• Dead time correction flag(dead_time_corrected)
• Number of samples used for cross-pol averages(nsamples_cross_pol_average)
• Attenuated backscatter, co-pol(signal_return_co_pol)
• Dummy altitude for Zeb(alt)
• Number of laser pulses summed during averaging interval(shots_per_sample)
• Polarization control voltage, co-pol(polarization_control_voltage_co_pol)
• Background signal, cross-pol(background_signal_cross_pol)
• time(time)
• Laser output energy per pulse(energy_monitor)
• Time offset of tweaks from base_time(time_offset)
• Array of heights for the range gates(height)
• Background signal standard deviation, co-pol(background_signal_std_co_pol)
• Telescope temperature(scope_temp)
• Background signal standard deviation, cross-pol(background_signal_std_cross_pol)
• Preliminary cloud base height above ground level, cross-pol(preliminary_cbh_cross_pol)
• Preliminary cloud base height above ground level, co-pol(preliminary_cbh_co_pol)
• Number of bins stored in data block(num_bins)
• *(aqc_signal_return_co_pol)
• Repetition Rate, or Trigger Frequency of the laser(pulse_rep)
• Attenuated backscatter, cross-pol(signal_return_cross_pol)
• *(aqc_signal_return_cross_pol)
• Number of detector channels(num_channels)
• Width of range-bins calculated from range_bin_time(range_bin_width)
• Number of samples used for co-pol averages(nsamples_co_pol_average)
• lon(lon)
• effective range offset due to poor sync between laser firing and A/D trigger.(range_offset)
• Detector Temperature(detector_temp)
• Distance from leading edge of first range bin to the center of each bin .(range_bins)
• Polarization control voltage, cross-pol(polarization_control_voltage_cross_pol)
• range(range)
• Maximum altitude retrieved from multichannel scalar card.(max_altitude)

HFE/MWRHF/M1 - Frosting/Condensation

The heater module was installed on 6/4/2008. Before this time there is condensation on the 
window during night time and early morning. On 8/18 the heater appears to have failed 
and nighttime condensation re-occurred on the radome during conditions of high humidity.

Users can identify the segments affected by observing a smooth steady increase in the 
brightness temperature (BT). BT values can increase to more than 250 K and then smoothly 
decrease. The RH during these events is usually above 70%. Users should disregard data 
affected by condensation.

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

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

HFE/MWRHF/M1 - Rain sensor failure

The rain sensor failed and the rain flag was always on.  When the rain flag is on the 
radiometer does not perform tip curves. The rain sensor was replaced 8/4.

• Rain flag(rain_flag)