We present here the code for an R-package which will soon become available at the Comprehensive R Archive Network (CRAN). The code is now available from this site as a zip file Rpackage.zip. Please address any questions to inga.maslova@gmail.com
The main functions are "SAI" (in the file index.R) and "SQ.new".
The first one computes the storm activity index associated with the ring current. It is an automated procedure that requires the user to input the raw magnetometer data and the coordinates of the stations used. The second major function of this package, "SQ", computes the estimate of the Solar quiet daily variation. Both functions are easy to use. The only requirement is that the data are provided in the matrix form. Below we provide the details on the use of these functions.
First, we describe basic requirements for function "SAI". In order to compute a storm index one must input the raw magnetometer records and the coordinates of the stations used. One can use any number of roughly equispaced equatorial stations.The input data should be provided as a matrix. Each column of this data matrix contains the records for each individual station. The coordinates should be written in form of a matrix as well. Each column corresponds to the station, the first row must contain the latitude and the second row -- longitude. This function returns the global storm index estimate.
In order to estimate the daily nonconstant variation, the "SQ" function can be used. First, the storm index must be calculated using the function "SAI". The resulting index is one of the "SQ.new" inputs. We recommend to use the data from at least two stations to estimate the daily variation. The data should be provided in the matrix form. Each column must contain records from different stations. This functions returns Sq estimated for each station individually.