NOAA Logo National Centers for Environmental Information

formerly the National Oceanographic Data Center (NODC)...  more on NCEI

NOAA Satellite and Information Service

You are here:HomeGTSPP › GTSPP FAQ

About Interpretation of QC Test Codes and Results

The GTSPP Quality Control (QC) test codes and results are stored in a eight-byte hexadecimal number, which can represent up-to 32 different tests and the test results. Each byte of the hexadecimal number has four (4) bits. A bit represents either 1 (one: test performed or failed) or 0 (zero: test not performed or passed) only.

The steps of interpretion of GTSPP QC test codes and results are as follows:

  1. Convert the QC test codes ( or results) from hexadecimal to decimal number.
  2. Convert the decimal number to binary number.
  3. Reverse the binary number in accordance with the order of the GTSPP QC test numbers.
  4. Map the reversed bit numbers to the cooresponding numbers of the QC tests in the ascending order and identify the test names and results, accordingly.
For example, the following table is a sample list of data quality control tests code (QCP$=41E1FFD) and results (QCF$=0000004) performed by the Integrated Scientific Data Management in Canada. The table indicates:
  1. The first test, 'Platform Identification Test", was performed (1=Y) and the test result showed "Passed" (0=P)
  2. The second test, "Impossible Date/Time", was not performed (0=N).
  3. The third test, "Impossible Location", was performed (1=Y) and passed (0=P).
  4. and so on...
Test Number
Stage Number
Test Name
Index Number
QCP$=41E1FFD (0=N/1=Y) QCF$=0000004 (0=P/1=F)
01 1.1 Platform Identification 1 1 0
02 1.2 Impossible Date/Time 2 0 0
03 1.3 Impossible Location 4 1 0
04 1.4 Position on Land 8 1 0
05 1.5 Impossible Speed 16 1 0
06 1.6 Impossible Sounding 32 0 0
07 2.1 Global Impossible Parameter Values 64 1 1
08 2.2 Regional Impossible Parameter Values 128 0 0
09 2.3 Increasing Depth 256 1 0
10 2.4 Profile Envelop 512 1 1
11 2.5 Constant Profile 1024 0 0
12 2.6 Freezing Point 2048 0 0
13 2.7 Spike 4096 1 1
14 2.8 Top and Bottom Spike 8192 1 0
15 2.9 Gradient 16384 1 1
16 2.10 Density Inversion 32768 0 0
17 3.1 Levitus Seasonal Statistics 65536 1 1
18 3.2 Emery and Dewar Climatology 131072 0 0
19 3.3 Asheville Climatology 262144 0 0
20 3.4 Levitus Monthly Climatology 524288 0 0
21 4.1 Waterfall 1048576 0 0
22 5.1 Cruise Track 2097152 1 0
23 5.2 Profiles 4194304 0 0
24 2.11 Bottom 8388608 0 0
25 2.12 Temperature Inversion 16777216 0 0
26 3.5 Levitus Annual Climatology
33554432
0 0

The list of data quality control tests and results but sorted by the test stage numbers is available here