Helioclim-1 automatic access

Last update: Jan. 2018

Several of our Customers use the HelioClim data as an alternative source of irradiation values. The machine-to-machine access to the data with the wget or curl commands is suited when you have to proceed to a large number of requests.

Automatic access with WGET

  1. Subscribe an annual access to HelioClim-1 (Contact us). Note that the automatic access to HelioClim-3 database also includes an automatic access to the HelioClim-1 database.
  2. Download wget.exe in a directory (on Windows - wget is available by default on Unix)
  3. In the same directory, create a text file and copy-paste in a single line the following instruction to test our free access to Carpentras, France:
 

wget -O output.csv --header="soda-user: guest" --header="soda-passwd: guest" "http://www.soda-is.com/pub/hc1_request.php?geopoint=44.083,5.059&firstday=1985-01-01&lastday=1985-01-05&duration=d&slope=0&azimuth=0"

  1. Rename the text file with the .bat extension and double click on it to retrieve the output file (Windows environment). Rename the text file with a .sh extension and run it using >my_script.sh in a Unix environment.

  The WGET command in details

Request:
wget -O output.csv --header="soda-user: login" --header=soda-passwd: password" ...
"http://server/pub/hc1_request.php?
geopoint=latitude,longitude& ...
firstday=yyyy-mm-dd&lastday=yyyy-mm-dd&duration=time_step& ...
slope=tilt_of_panels&azimuth=az_of_panels&albedo=ground_albedo"

Inputs:

  • login/password authentication: login and password provided by the SoDa team to access HelioClim-3 within the framework of your subscription. Note that a free permanent automatic access is set up for the site of Carpentras, France, where a Baseline Surface Radiation Network (BSRN) station is available with the login/password guest/guest
  • 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
  • altitude: in meters. Set "elevation=-999" to let SoDa get the elevation from Nasa SRTM database
  • yyyy-mm-dd: set the first and the last days of the request
  • time_step: "d" (daily), "w" (weekly) or "m" (monthly)
  • tilt_of_panels: must be 0 (horizontal) for daily requests. Possible values are 0 (horizontal) or -999 (sun tracking) for monthly requests.
  • az_of_panels: possible values are 0 (horizontal) or -999 (sun tracking)
  • ground_albedo: from "0.0" to "1.0". A usual inland value is "0.2"

Close to the output columns received via the Web interface. Differences are:

  • the separator is the space.

Warning! It is strongly recommanded to avoid the launch of parallel requests, using the "&" at the end of each wget request line. This would endanger our system.

Automatic access using CURL

You can also automatically retrieve HC1 Archives dataset by using the CURL command as follows:

Request (Windows):
curl -f -s -S -F stations=@stations.txt -o output.csv --header "soda-user: guest" --header "soda-passwd: guest" http://www.soda-is.com/pub/hc1_request.php

With the following stations.txt file format:
# Columns:
# id: station name
# latitude and longitude: in degrees, with at least 3 digits after comma
# elevation: ignored
# time reference: ignored
# duration: "d" (daily), "w" (weekly) or "m" (monthly)
# firstday and lastday: first and the last days of the request, expressed as yyyy-mm-dd
# slope of panel: must be 0 (horizontal) for daily requests. Possible values are 0 (horizontal) or -999 (sun tracking) for monthly requests.
# azimuth of panel: possible values are 0 (horizontal) or -999 (sun tracking)
# ground_albedo: from "0.0" to "1.0". A usual inland value is "0.2".
# horizon: ignored (optional)
# calibration: ignored (optional)
# format: ignored (optional)
#
#id         lat    lon   elevation time duration firstday   lastday    slope azimuth albedo
Carpentras1 44.083 5.059 -999      UT   d        1985-01-01 1985-01-31 0     0       0.2
Carpentras2 44.083 5.059 -999      UT   m        1985-01-01 1985-01-31 -999  -999    0.2
...


Please note that curl output does not contain headers.