Automatic Quality Checks (QC)

Automatic Quality Checks (QC)

Solar in-situ measurements (GHI, DHI and DNI) that are provided in the Web application have passed an automatic quality check (CQ) procedure. From initial raw in-situ measurements the QC procedure provide 3 type of time-series levels that are described below. Those QC procedures come from previous achievements from the EC funded project ENDORSE and are more detailed in this deliverable: D3.2 "Report on the harmonization and qualification of meteorological data" (PART B: QUALITY CHECK PROCEDURES (WP-3001-3) 43).

  1. QC1
  2. QC1-Completed
  3. QC-Full
  • Level QC1
    • Negative pyranometric measurement during night (SZA>93) set to 0
    • QC Extremely Rare Limits (ERL): values outside ERL set to NaN
QC-ERL

-2< GHI < 1.2 I0 cos(SZA)1.2 + 50

0.1 % of the data (during day)

0 < DNI < 0.95 I0 cos(SZA)0.2 + 10

0.1 % of the data (during day)

-2 < DHI < 0.75 I0 cos(SZA)1.2 + 30

2.5 % of the data (during day)
 
  • Level QC1-Completed
    • Negative pyranometric measurement during night (SZA>93) set to 0
    • QC Extremely Rare Limits (ERL)
      • Exclusion of values outside the ERL
      • Completion of these values (linear interpolation of clear-sky index, limited to 3-h gaps)
    • From QC1
    • With completion of these values (linear interpolation of clear-sky index, limited to 3-h gaps)
  • Level QC-Full
    • From QC1
    • QC Consistency Test - 2 components (T2C): 0.1 % rejected
    • AND QC Consistency Test - 3 components (T3C): 1.1 % rejected
    • AND rejection of GHI, DHI and DNI measurements for which these QCs cannot be conducted

ERL: QC w.r.t. Extremely Rare Limits 

0.03 GHItoa < GHI < 1.2 I0 cos(SZA)1.2 + 50

0 < DNI < 0.95 I0 cos(SZA)0.2 + 10

0.03 GHItoa < DHI < 0.75 I0 cos(SZA)1.2 + 30

T2C: Consistency QC with  2 components (GHI, DHI)

For GHI > 50 (if not, test not possible):

  •  DHI/GHI < 1.05, for SZA < 75°

  •  DHI/GHI < 1.10, for 93° > SZA > 75°

T3C: Consistency QC with 3 components (GHI, DHI, DNI)

For DHI+BHI > 50 (if not, test not possible)

  |GHI / (BHI+DHI)-1| ≤ 0.08, for SZA < 75°

  |GHI / (BHI+DHI)-1| ≤ 0.15, for 75°< SZA <93°