Data Quality Reports for Session: 104087 User: chwbear Completed: 02/06/2007


TABLE OF CONTENTS

DQR IDSubjectData Streams Affected
D060208.2SGP/SONDE/C1 - Mixed use of RS92-SGP and RS92-KL radiosondessgpsondewnpnC1.b1
D060630.1SGP/SONDE/C1 - No Wind/Lat/Lon Data in Sonde FilessgpsondewnpnC1.b1
D060803.2NSA/SONDE/C1 - Noisy/Unstable RH and dew point datansasondewnpnC1.b1
D060811.1NSA/SONDE/C1 - Bad surface RH and temperature valuesnsasondewnpnC1.b1
D060928.1NSA/SONDE/C1 - RH values offset due to error in ground checknsasondewnpnC1.b1
D060928.2SGP/SONDE/C1 - RH values offset due to error in ground checksgpsondewnpnC1.b1
D060928.3SGP/SONDE/C1 - Increased precision for alt, dp, pres, rh, tdrysgpsondewnpnC1.b1
D060928.4NSA/SONDE/C1 - Increased precision for alt, dp, pres, rh, tdrynsasondewnpnC1.b1
D061011.1NSA/SONDE/C1 - Incorrect surface values of T and RHnsasondewnpnC1.b1
D061114.3NSA/SONDE/C1 - RH sensor failurensasondewnpnC1.b1
D061201.1SGP/SONDE/C1 - RH Sensor failuresgpsondewnpnC1.b1
D070124.1NSA/SONDE/C1 - Incorrect surface RH valuensasondewnpnC1.b1


DQRID : D060208.2
Start DateStart TimeEnd DateEnd Time
02/10/2006000012/31/20062359
Subject:
SGP/SONDE/C1 - Mixed use of RS92-SGP and RS92-KL radiosondes
DataStreams:sgpsondewnpnC1.b1
Description:
Because of a manufacturer's production problem, we will be using both RS92-SGP (GPS 
windfinding and RS92-KL (Loran windfinding) radiosondes at the SGP/CF starting February 10, 
2006.  The radiosonde type used for the each sounding may be determined by looking the 
metadata variable "launch_status" in the netCDF data files.
Measurements:sgpsondewnpnC1.b1:
  • east longitude for all the input platforms.(lon)
  • model zonal wind velocity(u_wind)
  • surface wind speed(wspd)
  • model meridional wind velocity(v_wind)
  • north latitude for all the input platforms.(lat)
  • Wind Direction(deg)
  • Wind Status(wstat)


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DQRID : D060630.1
Start DateStart TimeEnd DateEnd Time
06/17/2006000006/21/20062359
Subject:
SGP/SONDE/C1 - No Wind/Lat/Lon Data in Sonde Files
DataStreams:sgpsondewnpnC1.b1
Description:
The wind finding hardware failed so that no wind or latitude/longitude data was collected 
on the launches for these days.
Measurements:sgpsondewnpnC1.b1:
  • east longitude for all the input platforms.(lon)
  • model zonal wind velocity(u_wind)
  • surface wind speed(wspd)
  • model meridional wind velocity(v_wind)
  • north latitude for all the input platforms.(lat)
  • Wind Status(wstat)


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DQRID : D060803.2
Start DateStart TimeEnd DateEnd Time
07/31/2006051507/31/20060523
Subject:
NSA/SONDE/C1 - Noisy/Unstable RH and dew point data
DataStreams:nsasondewnpnC1.b1
Description:
The RH readings during the first 8 minutes of this sounding include three apparently 
incorrect oscillations to near-zero values.  After checking the absolutely raw data, it seems 
as though this period was excessively noisy, resulting in many missing values.  The noise 
abatted and the remaining sounding values are valid.
Measurements:nsasondewnpnC1.b1:
  • Relative humidity scaled, by total column amount from MWR(rh)
  • Surface dew point temperature(dp)


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DQRID : D060811.1
Start DateStart TimeEnd DateEnd Time
07/30/2006052207/30/20060523
08/01/2006052008/01/20060521
08/04/2006053208/04/20060533
08/06/2006052808/06/20060529
08/08/2006051708/08/20060518
08/09/2006052708/09/20060528
08/11/2006052508/11/20060526
08/15/2006053408/15/20060535
08/17/2006053508/17/20060536
08/18/2006051608/18/20060517
08/19/2006053808/19/20060539
08/19/2006174508/19/20061746
08/20/2006053208/20/20060533
08/20/2006172908/20/20061730
08/21/2006053008/21/20060531
08/22/2006052408/22/20060525
Subject:
NSA/SONDE/C1 - Bad surface RH and temperature values
DataStreams:nsasondewnpnC1.b1
Description:
This is a subtle problem that might escape notice.  For the identified sonde launches, the 
ground station lost its signal between the time it was removed from the ground check set 
and the time it was launched.  As a result, the software, which automatically determines 
the launch time and surface conditions at time of launch mistakenly used values of 
temperature and RH representative of the ground check set and the GW rather than of the 
ambient conditions before launch.  The bad values influenced only the first few samples and the 
remainder of the sounding values are correct.  

A procedural problem was identified and corrected.
Measurements:nsasondewnpnC1.b1:
  • Relative humidity scaled, by total column amount from MWR(rh)
  • Dry-Bulb Temperature(tdry)
  • Surface dew point temperature(dp)


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DQRID : D060928.1
Start DateStart TimeEnd DateEnd Time
07/13/2006053209/26/20062359
Subject:
NSA/SONDE/C1 - RH values offset due to error in ground check
DataStreams:nsasondewnpnC1.b1
Description:
Background: After installation of the latest software update , we began performing formal 
ground checks on RS92 radiosondes.  By comparing the radiosonde readings with reference 
values in a controlled environment, the ground check is intended to ensure that the 
radiosonde sensors are in calibration before launch.  The radisonde values during the ground 
check process are recorded automatically; the reference values are entered by the operator. 
 If the radiosonde readings vary from the reference values, the system 'corrects' the 
radiosonde values.  In the case of RH, the correction is applied as an offset (true RH = 
indicated RH + correction).

Problem: Some operators misunderstood the ground-check procedure and entered the 
radiosonde values of RH rather than the reference value (assumed 0%RH), thus, some soundings done 
during this period have RH values that are different from what they would be if the 
ground check procedure had been done correctly.

Consequence:  Because the RH corrections generally are small (averaging about 0.5% RH) and 
the precision of the reported RH data during this time period is 1% RH, some values will 
not be affected at all; others will be off by about 1% RH (still within the stated 
accuracy of the sensor).  Furthermore, because entering the radiosonde value as the reference 
value results in a near zero 'correction,' one may view these soundings as being done 
without the ground check correction.  Also note that the dew point value will be suspect as well.

I am attaching below a listing of the soundings that were affected during the indicated 
time period.  Users can see the magnitude of the problem and choose whether or not to apply 
an offset in RH.  Note that application of the offset to the processed RH data (in the 
netCDF file) will not have the same effect of applying the correction to the absolutely 
raw data (before processing), but the differences should be insignificant.  Also note that 
the corrections for each sounding are included in the netCDF header information.  These 
attributes are named 'humidity_correction' and 'humidity_correction_2'.  The values of RH 
indicated by the radiosonde while it is in the ground check set are in attributes 
'humidity_gc_sonde' and 'humidity_gc_sonde_2.'  There is an RH reading for each of the two RH 
sensors used in the RS92 radiosonde.

Here is the list - RH1 and RH2 are the radiosonde readings in the ground check set.  Ref 
is the reference value entered by the operator.  The correcte reference value should be 
0%.  To obtain an approximation to the RH value that would have been recorded if the ground 
check had been done properly, subtract the Ref value from the indicated RH.

 YYYYMMDD  HHMM  SerialNo     RH1     RH2     Ref
 20060713  0532  B1924431    0.30    0.20    0.30
 20060713  1751  B1854963    0.20    0.30    0.30
 20060714  0521  B1924425    0.40    0.40    0.40
 20060714  1739  B1854206    0.30    0.30    0.30
 20060715  0522  B1715127    1.20    1.20    1.20
 20060715  1737  B1854966    0.60    0.60    0.60
 20060716  0508  B1715126    0.40    0.40    0.40
 20060716  1732  B1844098    0.50    0.50    0.50
 20060717  0517  B1914170    0.40    0.40    0.40
 20060718  0516  B1914173    0.70    0.70    0.70
 20060720  0523  B1854149    0.40    0.40    0.40
 20060721  0517  B1914153    0.40    0.40    0.40
 20060722  0521  B1844097    1.00    1.10    1.10
 20060722  1730  B1914174    0.60    0.70    0.70
 20060723  0537  B1714439    0.40    0.40    0.40
 20060723  1734  B1734155    0.50    0.50    0.50
 20060724  0529  B1134336    0.50    0.50    0.50
 20060725  0525  B1754099    0.60    0.70    0.70
 20060726  0541  B1844108    1.80    1.80    1.80
 20060727  0520  B1714382    0.70    0.80    0.70
 20060728  0531  B1854116    0.80    0.80    0.80
 20060729  0527  B1724027    1.00    1.00    1.00
 20060729  1726  B1714392    0.70    0.80    0.80
 20060730  0522  B1854100    0.70    0.80    0.80
 20060730  1724  B1854764    0.90    1.00    1.00
 20060731  0515  B1664086    0.90    0.80    0.90
 20060801  0520  B1724758    1.50    1.50    1.50
 20060801  1729  B1754116    1.10    1.10    1.10
 20060802  0518  B1724516    0.80    0.80    0.80
 20060803  0523  B1674148    0.80    0.80    0.80
 20060804  0532  B1754092    0.90    0.90    0.90
 20060804  1727  B1844117    3.50    3.50    3.50
 20060805  0531  B1714741    0.30    0.30    0.30
 20060805  1728  B1754098    0.30    0.30    0.30
 20060806  0528  B1844115    0.40    0.40    0.40
 20060806  1728  B1914161    0.20    0.20    0.20
 20060807  0530  B1714549    0.30    0.30    0.30
 20060808  0517  B1844107    0.50    0.50    0.50
 20060808  1744  B1914166    0.20    0.20    0.20
 20060809  0527  B1914164    0.30    0.40    0.40
 20060809  1736  B1914163    0.30    0.30    0.30
 20060810  0521  B1914160    0.40    0.50    0.50
 20060810  1745  B1744671    0.40    0.40    0.40
 20060811  0525  B1854965    0.50    0.50    0.50
 20060811  1753  B1724131    0.10    0.10    0.10
 20060812  0527  B1754104    0.50    0.50    0.50
 20060812  1740  B1854256    0.30    0.40    0.40
 20060813  0522  B1854240    0.30    0.40    0.40
 20060814  0525  B1714106    0.20    0.20    0.20
 20060814  1742  B1854106    0.40    0.40    0.40
 20060815  0534  B1914169    0.50    0.60    0.60
 20060815  1734  B1854233    0.60    0.70    0.70
 20060816  0539  B1724791    0.20    0.20    0.20
 20060816  1732  B1914171    0.10    0.20    0.20
 20060817  0535  B1354283    0.10    0.10    0.10
 20060817  1740  B1354574    0.40    0.40    0.40
 20060818  0516  B1354633    0.50    0.40    0.50
 20060818  1744  B1364673    0.20    0.20    0.20
 20060819  0538  B1364126    0.20    0.30    0.30
 20060819  1745  B1354598    0.50    0.60    0.60
 20060820  0532  B1354290    1.10    1.10    1.10
 20060820  1729  B1354317    0.40    0.40    0.40
 20060821  0530  B1354545    0.60    0.70    0.70
 20060821  1728  B1354516    0.70    0.70    0.70
 20060822  0524  B1354619    0.50    0.60    0.60
 20060822  1728  B1364377    0.40    0.40    0.40
 20060823  0533  B1354309    0.30    0.30    0.30
 20060823  1730  B1354527    0.70    0.70    0.70
 20060824  0533  B1354230    0.60    0.60    0.60
 20060824  1812  B1354587    0.70    0.70    0.70
 20060825  0517  B1354614    0.70    0.70    0.70
 20060825  1730  B1354630    0.60    0.60    0.60
 20060826  0537  B1334114    0.90    0.90    0.90
 20060826  1734  B1354246    0.70    0.70    0.70
 20060827  0508  B1354534    0.70    0.70    0.70
 20060827  1729  B1354618    0.60    0.60    0.60
 20060828  0517  B1354115    0.40    0.40    0.40
 20060828  1738  B1354206    0.50    0.60    0.60
 20060829  0516  B1354617    0.50    0.60    0.60
 20060829  1717  B1354622    0.50    0.60    0.60
 20060830  0511  B1354314    0.40    0.50    0.50
 20060830  1732  B1354537    0.60    0.70    0.70
 20060831  1802  B1354239    0.60    0.80    0.80
 20060905  1724  B1354626    0.60    0.60    0.60
 20060906  0522  B1354525    0.60    0.80    0.80
 20060906  1734  B1354107    0.50    0.50    0.50
 20060907  0537  B1354543    0.70    0.70    0.70
 20060907  1803  B1354586    0.80    0.80    0.80
 20060908  0531  B1354519    0.60    0.60    0.60
 20060908  1728  B1354224    0.60    0.60    0.60
 20060909  0534  B1354532    0.70    0.80    0.80
 20060909  1732  B1354513    0.80    0.90    0.90
 20060910  0516  B1354125    0.60    0.70    0.60
 20060910  1727  B1354110    0.40    0.50    0.50
 20060911  0528  B1354235    0.90    0.90    0.90
 20060911  1849  B1354514    0.70    0.70    0.70
 20060912  0525  B1354124    0.60    0.70    0.70
 20060913  0534  B1344478    0.50    0.50    0.50
 20060914  0520  B1354226    0.70    0.70    0.70
 20060915  0529  B1344459    0.40    0.50    0.50
 20060916  0532  B1344469    0.50    0.40    0.50
 20060916  1732  B1354106    0.50    0.60    0.60
 20060917  0527  B1354210    0.70    0.70    0.70
 20060918  0533  B1354087    0.60    0.60    0.60
 20060919  0526  B1354097    0.70    0.50    0.60
 20060920  0516  B1344462    0.50    0.40    0.50
 20060920  1810  B1354536    0.70    0.70    0.70
 20060921  0534  B1354112    0.50    0.60    0.60
 20060921  1800  B1344502    0.40    0.40    0.40
 20060922  0525  B1354531    0.70    0.80    0.80
 20060922  1736  B1354541    0.70    0.70    0.70
 20060923  0519  B1354101    0.50    0.60    0.60
 20060923  1738  B1354576    0.70    0.50    0.70
 20060924  0536  B1354095    0.60    0.60    0.60
 20060925  0536  B1354098    0.60    0.60    0.60
 20060925  1755  B1354100    0.50    0.50    0.50
 20060926  0531  B1334691    0.70    0.70    0.70
 20060926  1742  B1354108    0.40    0.50    0.50
Measurements:nsasondewnpnC1.b1:
  • Relative humidity scaled, by total column amount from MWR(rh)
  • Surface dew point temperature(dp)


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DQRID : D060928.2
Start DateStart TimeEnd DateEnd Time
08/27/2006233209/25/20061600
Subject:
SGP/SONDE/C1 - RH values offset due to error in ground check
DataStreams:sgpsondewnpnC1.b1
Description:
Background: After installation of the latest software update , we began performing formal 
ground checks on RS92 radiosondes.  By comparing the
radiosonde readings with reference values in a controlled environment, the
ground check is intended to ensure that the radiosonde sensors are in
calibration before launch.  The radisonde values during the ground check
process are recorded automatically; the reference values are entered by the
operator.  If the radiosonde readings vary from the reference values, the
system 'corrects' the radiosonde values.  In the case of RH, the correction
is applied as an offset (true RH = indicated RH + correction).

Problem: Some operators misunderstood the ground-check procedure and entered the 
radiosonde values of RH rather than the reference value (assumed 0%RH), thus, some soundings done 
during this period have RH values that are different from what they would be if the 
ground check procedure had been done correctly.

Consequence:  Because the RH corrections generally are small (averaging
about 0.5% RH) and the precision of the reported RH data during this time
period is 1% RH, some values will not be affected at all; others will be off by about 1% 
RH (still within the stated accuracy of the sensor). 
Furthermore, because entering the radiosonde value as the reference value
results in a near zero 'correction,' one may view these soundings as being
done without the ground check correction.  Also note that the dew point
value will be suspect as well.

I am attaching below a listing of the soundings that were affected during the indicated 
time period.  Users can see the magnitude of the problem and choose whether or not to apply 
an offset in RH.  Note that application of the offset to the processed RH data (in the 
netCDF file) will not have the same effect of applying the correction to the absolutely 
raw data (before processing), but the differences should be insignificant.  Also note that 
the corrections for each sounding are included in the netCDF header information.  These 
attributes are named 'humidity_correction' and 'humidity_correction_2'.  The values of RH 
indicated by the radiosonde while it is in the ground check set are in attributes 
'humidity_gc_sonde' and 'humidity_gc_sonde_2.'  There is an RH reading for each of the two RH 
sensors used in the RS92 radiosonde.

Here is the list - RH1 and RH2 are the radiosonde readings in the ground
check set.  Ref is the reference value entered by the operator.  The
correcte reference value should be 0%.  To obtain an approximation to the RH value that 
would have been recorded if the ground check had been done
properly, subtract the Ref value from the indicated RH.

 YYYYMMDD  HHMM  SerialN      RH1     RH2     Ref
 20060827  2332  B2624322    1.00    1.00    1.00
 20060828  1731  B2634078    1.00    1.00    1.00
 20060828  2332  B2624380    3.00    3.00    2.00
 20060909  2331  B2615266    1.00    1.00    1.00
 20060915  1759  B2914012    1.00    1.00    1.00
 20060919  2350  B2825128    1.00    1.00    1.00
 20060920  1800  B2825088    1.00    1.00    1.00
 20060920  2346  B2815633    1.00    1.00    1.00
 20060921  1728  B2834732    1.30    1.30    1.30
 20060921  2330  B2825042    1.50    1.50    1.50
 20060922  0527  B2825043    1.70    1.80    1.70
 20060922  1128  B2825031    1.60    1.50    1.60
 20060922  1729  B2834437    1.50    1.50    1.50
 20060922  2330  B2825040    0.40    0.50    0.50
 20060923  0529  B2834733    0.30    0.30    0.30
 20060923  1128  B2825026    0.40    0.40    0.40
 20060923  1729  B2825064    0.60    0.70    0.60
 20060923  2330  B2825041    0.40    0.50    0.50
 20060924  0529  B2825039    0.30    0.30    0.30
 20060924  1729  B2825025    0.20    0.30    0.20
 20060924  2329  B2825032    0.30    0.40    0.40
 20060925  0529  B2824234    0.20    0.30    0.20
Measurements:sgpsondewnpnC1.b1:
  • Surface dew point temperature(dp)
  • Relative humidity scaled, by total column amount from MWR(rh)


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DQRID : D060928.3
Start DateStart TimeEnd DateEnd Time
09/28/2006172812/31/99992359
Subject:
SGP/SONDE/C1 - Increased precision for alt, dp, pres, rh, tdry
DataStreams:sgpsondewnpnC1.b1
Description:
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.
Measurements:sgpsondewnpnC1.b1:
  • 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)


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DQRID : D060928.4
Start DateStart TimeEnd DateEnd Time
09/29/2006050012/31/99992359
Subject:
NSA/SONDE/C1 - Increased precision for alt, dp, pres, rh, tdry
DataStreams:nsasondewnpnC1.b1
Description:
The output precision of the following variables was increased 20060929:

   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.
Measurements:nsasondewnpnC1.b1:
  • Relative humidity scaled, by total column amount from MWR(rh)
  • Dry-Bulb Temperature(tdry)
  • altitude above sea levelaltunits(alt)
  • pressure at constant pressure surface(pres)
  • Surface dew point temperature(dp)


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DQRID : D061011.1
Start DateStart TimeEnd DateEnd Time
10/07/2006052410/07/20060525
Subject:
NSA/SONDE/C1 - Incorrect surface values of T and RH
DataStreams:nsasondewnpnC1.b1
Description:
The radiosonde was launched too quickly after being removed from the ground check set.  As 
a result, the system did not equilibrate with the local ground conditions and the 
automatically entered surface values are incorrect.
Measurements:nsasondewnpnC1.b1:
  • Relative humidity scaled, by total column amount from MWR(rh)
  • Dry-Bulb Temperature(tdry)
  • Surface dew point temperature(dp)


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DQRID : D061114.3
Start DateStart TimeEnd DateEnd Time
10/28/2006053210/28/20060710
Subject:
NSA/SONDE/C1 - RH sensor failure
DataStreams:nsasondewnpnC1.b1
Description:
It appears that one of the two RH sensors on this radiosonde was affected by ice after 
emerging from a low cold cloud.  As a result the reported RH values oscillate by about 10 
percent until the alternate heating cycle stops.  I suspect the lower value is more close 
to correct, but can't be absolutely sure.
Measurements:nsasondewnpnC1.b1:
  • Relative humidity scaled, by total column amount from MWR(rh)
  • Surface dew point temperature(dp)


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DQRID : D061201.1
Start DateStart TimeEnd DateEnd Time
11/27/2006233111/28/20060056
Subject:
SGP/SONDE/C1 - RH Sensor failure
DataStreams:sgpsondewnpnC1.b1
Description:
The differences between the two RH sensors on this sonde are unreasonably high (~20%).  As 
a result the reported RH values oscillate by this amount during the times the sensors 
are alternately heated.  After the heating stops, the reported RH comes from the sensor 
reading the higher value.  There is no way of knowing if this is the correct value.
Measurements:sgpsondewnpnC1.b1:
  • Surface dew point temperature(dp)
  • Relative humidity scaled, by total column amount from MWR(rh)


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DQRID : D070124.1
Start DateStart TimeEnd DateEnd Time
12/29/2006051712/29/20060518
Subject:
NSA/SONDE/C1 - Incorrect surface RH value
DataStreams:nsasondewnpnC1.b1
Description:
For an unknown reason the surface RH was reported a 0%.  Becuase these values are entered 
automatically by the system, this is NOT likely an operator error.  Examination of the 
raw data shows that the surface RH at launch time was approximately 81.2 %RH.
Measurements:nsasondewnpnC1.b1:
  • Relative humidity scaled, by total column amount from MWR(rh)
  • Surface dew point temperature(dp)


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