SGP/SONDE/C1 - Bad RH Data

The RH values below 6 km are incorrect.  The problem relates to a failure of the GC25 
ground check set used before this particular sounding.  The failure seems to have affected 
the sensor calibration with the effect that one of the two sensors was reading artificially 
high.  Because the internal processing software uses the highest of the two sensor 
readings, the bad sensor value is chosen whenever it is not heated.

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)

SGP/RL/C1 - Mode0 data incorrect

The Raman lidar is being upgraded to add additional detection channels.  As part of this 
work, many of the filter wheel controllers were removed from the lidar and thus the 
operation modes of the lidar were changed.  During the time period specified, the "mode0" data 
(these are the samples where the field "filter" equals 0) are incorrect; however, all 
other data are fine.  

The mode0 data are used to determine the electronic background profiles for the 
analog-to-digital datastreams; however, these electronic background profiles can be determined from 
data collected after 1315 UTC on 3 Aug after this bug was fixed.

• Raw data stream - documentation not supported(Raw data stream - documentation not supported)

• east longitude for all the input platforms.(lon)
• Number of photons counted in the low elastic (aerosol) channel(elastic_counts_low)
• Relative humidity scaled, by total column amount from MWR(rh)
• Number of laser shots recorded for the high nitrogen channel(shots_summed_nitrogen_high)
• Number of photons counted in the high water vapor channel(water_counts_high)
• Supplemental 11(s11)
• Supplemental 8(s8)
• Temperature 3 inside the instrument enclosure(temp3)
• altitude above sea levelaltunits(alt)
• Number of laser shots recorded for the low elastic channel(shots_summed_elastic_low)
• Summed analog signal in the low water vapor channel(water_analog_low)
• Supplemental 9(s9)
• Time offset from midnight of date of file. For CO data, this is identical to
  time_offset and is included for compatibility.(time)
• Supplemental 10(s10)
• Time offset of tweaks from base_time(time_offset)
• Number of laser shots recorded for the high elastic channel(shots_summed_elastic_high)
• Number of laser shots recorded for the low nitrogen channel(shots_summed_nitrogen_low)
• Number of photons counted in the high nitrogen channel(nitrogen_counts_high)
• Summed analog signal in the high water vapor channel(water_analog_high)
• Number of laser shots recorded for the low water channel(shots_summed_water_low)
• Number of photons counted in the high depolarization channel(depolarization_counts_high)
• Supplemental 5(s5)
• Summed analog signal in the low elastic channel(elastic_analog_low)
• Temperature 1 inside the instrument enclosure(temp1)
• Supplemental 6(s6)
• Summed analog signal in the high nitrogen channel(nitrogen_analog_high)
• Time offset from base_time(base_time)
• Temperature 6 inside the instrument enclosure(temp6)
• Summed analog signal in the high depolarization channel(depolarization_analog_high)
• Supplemental 3(s3)
• Nominal number of seconds of data acquired(acquisition_time)
• Number of laser pulses summed during measurement interval(shots_summed)
• N2 cloud check value(n2_cloud_check_value)
• Number of photons counted in the low water vapor channel(water_counts_low)
• Supplemental 12(s12)
• Number of photons counted in the high elastic (aerosol) channel(elastic_counts_high)
• Temperature 4 inside the instrument enclosure(temp4)
• Summed analog signal in the high elastic channel(elastic_analog_high)
• Number of laser shots recorded for the high depolarization channel(shots_summed_depolarization_high)
• Supplemental 1(s1)
• Summed analog signal in the low nitrogen channel(nitrogen_analog_low)
• Cloud value check flag(cloud_value_check)
• Temperature 5 inside the instrument enclosure(temp5)
• Supplemental 2(s2)
• Supplemental 7(s7)
• Temperature 2 inside the instrument enclosure(temp2)
• north latitude for all the input platforms.(lat)
• Number of photons counted in the low nitrogen channel(nitrogen_counts_low)
• Laser head in use(laser_head)
• Laser pulse energy(pulse_energy)
• Flag indicating the filters (or lack of) added to the instrument(filter)
• Supplemental 4(s4)
• Number of laser shots recorded for the high water channel(shots_summed_water_high)

SGP/SONDE/C1 - Bad T/RH and surface P.

Apparently multiple failures.  The radiosonde temperature sensor broke on launch causing 
an approximate 35 degC negative offset and as a result, the RH is incorrect.  Furthermore, 
it appears that the pressure sensor was off by approximately 4 hPa, though this would 
not affect the altitude calculation, the absolute pressure is wrong.

• Dry-Bulb Temperature(tdry)
• Relative humidity scaled, by total column amount from MWR(rh)
• pressure at constant pressure surface(pres)

SGP/SONDE/C1 - Increased precision for alt, dp, pres, rh, tdry

The output precision of the following variables was increased 20060928

alt  changed from 1m to 0.1m
dp   changed from 0.1degC to 0.01degC
pres changed from 0.1 hPa to 0.01 hPa
RH   changed from 1%RH to 0.01%RH
tdry changed from .1degC to 0.01degC

Note that the increase in precision does not necessarily imply an increase in accuracy.  
Users are cautioned to continue to use their best scientific judgement when using these or 
any other data.

• Surface dew point temperature(dp)
• Dry-Bulb Temperature(tdry)
• Relative humidity scaled, by total column amount from MWR(rh)
• pressure at constant pressure surface(pres)
• altitude above sea levelaltunits(alt)