HC3 Similarity Forecast automatic access 

Last update: Jul. 2017

    Command - Inputs - Outputs - Try me

- FOR PAY - Contact us to receive your_login and your_password

The hc3v4_similarity_forecast.php automatic access provides time series of HelioClim-3 version 4 data for the next day. The Similarity Forecast method explores the HelioClim-3 database to find similar meteorological events in the past in order to make an estimation of the next day irradiation values. We recommend to use this service after sunset today to retrieve the most pertinent data for tomorrow.

Please contact us for a quotation.

Command

On Windows, first download wget.exe executable in your working directory. In the same directory, create a text file in which you copy-paste the following command. Then rename the .txt file with the .bat extension. Double click on the .bat file to retrieve the output.csv file.

Request (Windows):
wget -O output.csv --header="soda-user: your_login" --header="soda-passwd: your_password" ...
"http://server/pub/hc3v4_similarity_forecast.php?geopoint=latitude,longitude&elevation=altitude ...
&firstday=yyyy-mm-dd&lastday=yyyy-mm-dd&duration=time_step&time=time_reference&slope=tilt_of_panels ...
&azimuth=az_of_panels&albedo=ground_albedo&horizon=boolean_horizon
"

Inputs:

  • your_login and your_password: this access is restricted to registered users, i.e. to users who purchased an automatic access to the data. Please contact us for a quotation or to receive your SoDa automatic access credentials 
  • Server: "www.soda-is.com" (main server) or "pro.soda-is.com" (mirror server)
  • latitude and longitude: in degrees, with at least 3 digits after comma, e.g. "geopoint=45.563,7.25"
  • altitude: in meters. Set "elevation=-999" to let SoDa get the elevation from Nasa SRTM database
  • yyyy-mm-dd: we recommend to set first day and last day to tomorrow as soon as sun sets today
  • time_step: "1", "5", "10", "15" (minutes), "h" (hourly)
  • time_reference: "TU" (universal time) or "TST" (True Solar Time)
  • tilt_of_panels: from "0" (horizontal) to "90", or "-999" for sun tracking. For more information on plane orientations, please refer to http://www.soda-pro.com/help/general/plane-orientations-and-radiation-components
  • az_of_panels: from "0" (North), 90° (East), 180° (South) to 270° (West), or "-999" for sun tracking. For more information on plane orientations, please refer to http://www.soda-pro.com/help/general/plane-orientations-and-radiation-components
  • ground_albedo: from "0.0" to "1.0". A usual inland value is "0.2". Optional, if not set, default value is "0.2".
  • boolean_horizon: takes into account "1" or not "0" the far horizon. Optional, if not set, default value is "0".

Outputs:

Compared to the output column content available in the standard HelioClim-3 services, two points differ:

  • The header is by default available
  • A reliability column is available before the last column of Top of Atmosphere irradiation values.
    The reliability column has several forms depending of the time step:
    • Code: 0: no data, 1: sun below horizon, 2: satellite assessment, 5: interpolation in time, 6: forecast
    • Nb slots (%): ratio of the number of valid slots and the number of slots during the daylength in percent
    • Nb valid days: number of valid days in the period
NB: For the SoDa Customers who already exploit the output format of hc3v4_request.php, it is possible to get back to this format by adding the following parameters "rely=0&header=0"

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For more details on building your command in a Unix environment, Error messages, and FAQ, please refer to this page (Coming soon).

Try me: permanent access to Carpentras, France

wget -O Carpentras.csv --header="soda-user: guest" --header="soda-passwd: guest" ...
"http://www.soda-is.com/pub/hc3v4_similarity_forecast.php?geopoint=44.083,5.059
&elevation=-999&firstday=2017-07-29&lastday=2017-01-31&duration=15&time=UT&slope=25&azimuth=180
"

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