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HelioClim3 specifications by service

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Each service is described as follows: input parameters, output column content, other services included, ...


NB: The date or instant given for each value corresponds to the end of the summarization/time integration. I.e. 24/04/2010 08:00 means that the associated irradiation or irradiance value has been measured between 07:00 and 08:00. This convention addresses the standard recommanded by the WMO (World Meteorological Organisation).

HCmonth

INPUTS: Latitude, Longitude, Altitude (optional), first and last dates of the temporal interval, output format (html=>screen, or csv=>text file)

OUTPUTS
1 2 3 4 5 6 7 8 9 10
           month Irradiance Lower bound Upper bound Nb data Top of Atmosphere Clear-Sky Irradiation Irradiation J/cm²
  • 1: year
  • 2: month: number of the month in the year
  • 3: GHI: irradiance averaged over the period in W/m² (-999 if no data)
  • 4: lower: lower bound of the uncertainty on the irradiance values in W/m²
  • 5: upper: upper bound of the uncertainty on the irradiance values in W/m²
  • 6: Nb data: number of valid days in the month
  • 7: ToA: downwards irradiance averaged over the period at the top of the atmophere (extraterrestrial) in W/m²
  • 8: Cls: typical irradiance averaged over the period if the sky were clear in W/m²
  • 9: GHI: monthly mean of daily irradiation in Wh/m² (-999 if no data)
  • 10: GHI: monthly mean of daily irradiation in J/cm² (-999 if no data)

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HCweek

1 2 3 4 5 6 7 8 9 10 11
           month day Irradiance Lower bound Upper bound Nb data Top of Atmosphere Clear-Sky Irradiation Irradiation J/cm²
  • 1: year
  • 2: number of the month in the year
  • 3: number of the first day of each week in the month
  • 4: irradiance averaged over the period in W/m² (-999 if no data)
  • 5: lower bound of the uncertainty on the irradiance values in W/m²
  • 6: upper bound of the uncertainty on the irradiance values in W/m²
  • 7: number of valid days in the week
  • 8: downwards irradiance averaged over the period at the top of the atmophere (extraterrestrial) in W/m²
  • 9: typical irradiance averaged over the period if the sky were clear in W/m²
  • 10: weekly mean of daily irradiation in Wh/m² (-999 if no data)
  • 11: weekly mean of daily irradiation in J/cm² (-999 if no data)

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HCday

1 2 3 4 5 6 7 8 9 10 11
           month day Irradiance Lower bound Upper bound Nb data Top of Atmosphere Clear-Sky Irradiation Irradiation J/cm²
  • 1: year
  • 2: number of the month in the year
  • 3: number of the day in the month
  • 4: irradiance averaged over the period in W/m² (-999 if no data)
  • 5: lower bound of the uncertainty on the irradiance values in W/m²
  • 6: upper bound of the uncertainty on the irradiance values in W/m²
  • 7: ratio of the number of valid slots and the number of slots during the daylength in percent (%)
  • 8: downwards irradiance averaged over the period at the top of the atmophere (extraterrestrial) in W/m²
  • 9: typical irradiance averaged over the period if the sky were clear in W/m²
  • 10: irradiation over the period in Wh/m² (-999 if no data)
  • 11: irradiation over the period in J/cm² (-999 if no data)

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HChour

1 2 3 4 5 6 7 8 9 10 11
           month day time Irradiance Lower bound Upper bound Nb data Top of Atmosphere Clear-Sky Irradiation
  • 1: year
  • 2: number of the month in the year
  • 3: number of the day in the month
  • 4: hour in the day
  • 5: irradiance averaged over the period in W/m² (-999 if no data)
  • 6: lower bound of the uncertainty on the irradiance values in W/m²
  • 7: upper bound of the uncertainty on the irradiance values in W/m²
  • 8: code: 0: no data; 1: sun below horizon; 2: satellite assessment; 5: interpolation in time
  • 9: downwards irradiance averaged over the period at the top of the atmophere (extraterrestrial) in W/m²
  • 10: typical irradiance averaged over the period if the sky were clear in W/m²
  • 11: irradiation over the period in Wh/m² (-999 if no data)

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HC15

1 2 3 4 5 6 7 8 9 10 11
           month day time Irradiance Lower bound Upper bound Nb data Top of Atmosphere Clear-Sky Irradiation
  • 1: year
  • 2: number of the month in the year
  • 3: number of the day in the month
  • 4: decimal hour in the day
  • 5: irradiance averaged over the period in W/m² (-999 if no data)
  • 6: lower bound of the uncertainty on the irradiance values in W/m²
  • 7: upper bound of the uncertainty on the irradiance values in W/m²
  • 8: code: 0: no data; 1: sun below horizon; 2: satellite assessment; 5: interpolation in time
  • 9: downwards irradiance averaged over the period at the top of the atmophere (extraterrestrial) in W/m²
  • 10: typical irradiance averaged over the period if the sky were clear in W/m²
  • 11: irradiation over the period in Wh/m² (-999 if no data)

  More information about the lower and upper bounds
From the global comparison made between Helioclim and the ground stations, some corrections are brought to the database values to reduce globally the bias. You can find some uncertainty results here
From all these comparisons, a classification (bins) of bias which mostly depends on the sun position in the sky is derived. These bins are then used to compute the lower and upper bounds of the GHI for the hour slot. With this algorithm, nothing guaranties that the upper bound is lower than the clear sky value and effectively, it happens that mostly for near clear sky days that the upper bound is higher than the clear sky value.
These bounds are intended to give an estimate of the error. Concerning the lower and upper irradiance bounds, here are the equations: Lower bound = I + relativeBias - relativeStandardDeviation Upper bound = I + relativeBias + relativeStandardDeviation Where the "relativeBias" and the "relativeStandardDeviation" are computed using the ground station data we have available in order to assess the quality of our database HelioClim3. We have exactly 29 stations. The description of the results are available at: http://www.soda-is.com/eng/help/helioclim3_uncertainty_eng.html There is a 68% chance that the actual value is comprised between lower and upper bounds.
A paper describing this method is in preparation.

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HCmonthincl

1 2 3 4 5 6 7 8 9 10 11
           Month Nb valid days Direct Inclined Diffuse Inclined Reflected Global Inclined Direct Horiz Diffus Horiz Global Horiz Top of Atmosphere
  • 1: year
  • 2: number of the month in the year
  • 3: number of valid days in the month
  • 4: direct inclined irradiation averaged over the period in Wh/m² (-999 if no data)
  • 5: diffuse inclined irradiation averaged over the period in Wh/m² (-999 if no data)
  • 6: reflected inclined irradiation averaged over the period in Wh/m² (-999 if no data)
  • 7: global inclined irradiation averaged over the period in Wh/m² (-999 if no data)
  • 8: direct horizontal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 9: diffuse horizontal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 10: global horizontal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 11: downwards irradiance averaged over the period at the top of the atmophere (extraterrestrial) in Wh/m²

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HCdayIncl

1 2 3 4 5 6 7 8 9 10 11
           Month Day Direct Inclined Diffuse Inclined Reflected Global Inclined Direct Horiz Diffus Horiz Global Horiz Top of Atmosphere
  • 1: year
  • 2: number of the month in the year
  • 3: number of the day in the month
  • 4: direct inclined irradiation averaged over the period in Wh/m² (-999 if no data)
  • 5: diffuse inclined irradiation averaged over the period in Wh/m² (-999 if no data)
  • 6: reflected inclined irradiation averaged over the period in Wh/m² (-999 if no data)
  • 7: global inclined irradiation averaged over the period in Wh/m² (-999 if no data)
  • 8: direct horizontal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 9: diffuse horizontal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 10: global horizontal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 11: downwards irradiance averaged over the period at the top of the atmophere (extraterrestrial) in Wh/m²

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HChourIncl

1 2 3 4 5 6 7 8 9 10 11 12
           Month Day Hour Direct Inclined Diffuse Inclined Reflected Global Inclined Direct Horiz Diffus Horiz Global Horiz Top of Atmosphere
  • 1: year
  • 2: number of the month in the year
  • 3: number of the day in the month
  • 4: hour in the day
  • 5: direct inclined irradiation averaged over the period in Wh/m² (-999 if no data)
  • 6: diffuse inclined irradiation averaged over the period in Wh/m² (-999 if no data)
  • 7: reflected inclined irradiation averaged over the period in Wh/m² (-999 if no data)
  • 8: global inclined irradiation averaged over the period in Wh/m² (-999 if no data)
  • 9: direct horizontal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 10: diffuse horizontal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 11: global horizontal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 12: downwards irradiance averaged over the period at the top of the atmophere (extraterrestrial) in Wh/m²

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HC15incl

1 2 3 4 5 6 7 8 9 10 11 12
           Month Day Hour Direct Inclined Diffuse Inclined Reflected Global Inclined Direct Horiz Diffus Horiz Global Horiz Top of Atmosphere
  • 1: year
  • 2: number of the month in the year
  • 3: number of the day in the month
  • 4: decimal hour in the day
  • 5: direct inclined irradiation averaged over the period in Wh/m² (-999 if no data)
  • 6: diffuse inclined irradiation averaged over the period in Wh/m² (-999 if no data)
  • 7: reflected inclined irradiation averaged over the period in Wh/m² (-999 if no data)
  • 8: global inclined irradiation averaged over the period in Wh/m² (-999 if no data)
  • 9: direct horizontal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 10: diffuse horizontal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 11: global horizontal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 12: downwards irradiance averaged over the period at the top of the atmophere (extraterrestrial) in Wh/m²

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HCmonthDNI

1 2 3 4 5 6 7 8 9 10 11
           Month Nb valid days Direct NI Diffuse NI Reflected Global NI Direct Horiz Diffus Horiz Global Horiz Top of Atmosphere
  • 1: year
  • 2: number of the month in the year
  • 3: number of valid days in the month
  • 4: direct normal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 5: diffuse normal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 6: reflected normal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 7: global normal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 8: direct horizontal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 9: diffuse horizontal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 10: global horizontal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 11: downwards irradiance averaged over the period at the top of the atmophere (extraterrestrial) in Wh/m²

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HCdayDNI

1 2 3 4 5 6 7 8 9 10 11
           Month Days Direct NI Diffuse NI Reflected Global NI Direct Horiz Diffus Horiz Global Horiz Top of Atmosphere
  • 1: year
  • 2: number of the month in the year
  • 3: number of the day in the month
  • 4: direct normal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 5: diffuse normal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 6: reflected normal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 7: global normal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 8: direct horizontal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 9: diffuse horizontal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 10: global horizontal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 11: downwards irradiance averaged over the period at the top of the atmophere (extraterrestrial) in Wh/m²

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HChourDNI

1 2 3 4 5 6 7 8 9 10 11 12
           Month Day Hour Direct NI Diffuse NI Reflected Global NI Direct Horiz Diffus Horiz Global Horiz Top of Atmosphere
  • 1: year
  • 2: number of the month in the year
  • 3: number of the day in the month
  • 4: hour in the day
  • 5: direct normal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 6: diffuse normal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 7: reflected normal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 8: global normal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 9: direct horizontal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 10: diffuse horizontal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 11: global horizontal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 12: downwards irradiance averaged over the period at the top of the atmophere (extraterrestrial) in Wh/m²

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HC15DNI

1 2 3 4 5 6 7 8 9 10 11 12
           Month Day Hour Direct NI Diffuse NI Reflected Global NI Direct Horiz Diffus Horiz Global Horiz Top of Atmosphere
  • 1: year
  • 2: number of the month in the year
  • 3: number of the day in the month
  • 4: decimal hour in the day
  • 5: direct normal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 6: diffuse normal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 7: reflected normal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 8: global normal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 9: direct horizontal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 10: diffuse horizontal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 11: global horizontal irradiation averaged over the period in Wh/m² (-999 if no data)
  • 12: downwards irradiance averaged over the period at the top of the atmophere (extraterrestrial) in Wh/m²

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