wmm_point.c

Go to the documentation of this file.

//---------------------------------------------------------------------------

#include <stdio.h>
#include <string.h>
#include <math.h>
#include <stdlib.h>


#include "GeomagnetismHeader.h"
//#include "GeomagnetismLibrary.c"
#include "EGM9615.h"

//---------------------------------------------------------------------------

/* 
WMM Point Calculation Program.

The Geomagnetism Library is used to make a command prompt program. The program prompts
the user to enter a location, performs the computations and prints the results to the
standard output. The program expects the files GeomagnetismLibrary.c, GeomagnetismHeader.h,
WMM.COF and EGM9615.h to be in the same directory. 

Manoj.C.Nair@Noaa.Gov
April 21, 2011

 *  Revision Number: $Revision: 842 $
 *  Last changed by: $Author: awoods $
 *  Last changed on: $Date: 2012-04-20 14:59:13 -0600 (Fri, 20 Apr 2012) $
 */

int main()
{
    MAGtype_MagneticModel * MagneticModels[1], *TimedMagneticModel;
    MAGtype_Ellipsoid Ellip;
    MAGtype_CoordSpherical CoordSpherical;
    MAGtype_CoordGeodetic CoordGeodetic;
    MAGtype_Date UserDate;
    MAGtype_GeoMagneticElements GeoMagneticElements;
    MAGtype_Geoid Geoid;
    char ans[20], b;
    char filename[] = "WMM.COF";
    char VersionDate_Large[] = "$Date: 2012-04-20 14:59:13 -0600 (Fri, 20 Apr 2012) $";
    char VersionDate[12];
    int NumTerms, Flag = 1, nMax = 0;
    int epochs = 1;
    /* Memory allocation */

    strncpy(VersionDate, VersionDate_Large + 39, 11);
    VersionDate[11] = '\0';
    MAG_robustReadMagModels(filename, &MagneticModels, epochs);
    if(nMax < MagneticModels[0]->nMax) nMax = MagneticModels[0]->nMax;
    NumTerms = ((nMax + 1) * (nMax + 2) / 2);
    TimedMagneticModel = MAG_AllocateModelMemory(NumTerms); /* For storing the time modified WMM Model parameters */
    if(MagneticModels[0] == NULL || TimedMagneticModel == NULL)
    {
        MAG_Error(2);
    }
    MAG_SetDefaults(&Ellip, &Geoid); /* Set default values and constants */
    /* Check for Geographic Poles */


    //MAG_InitializeGeoid(&Geoid);    /* Read the Geoid file */

    /* Set EGM96 Geoid parameters */
    Geoid.GeoidHeightBuffer = GeoidHeightBuffer;
    Geoid.Geoid_Initialized = 1;
    /* Set EGM96 Geoid parameters END */
    b = MAG_GeomagIntroduction_WMM(MagneticModels[0], VersionDate);
    while(Flag == 1 && b != 'x')
    {
        if(MAG_GetUserInput(MagneticModels[0], &Geoid, &CoordGeodetic, &UserDate) == 1) /*Get User Input */
        {
            MAG_GeodeticToSpherical(Ellip, CoordGeodetic, &CoordSpherical); /*Convert from geodetic to Spherical Equations: 17-18, WMM Technical report*/
            MAG_TimelyModifyMagneticModel(UserDate, MagneticModels[0], TimedMagneticModel); /* Time adjust the coefficients, Equation 19, WMM Technical report */
            MAG_Geomag(Ellip, CoordSpherical, CoordGeodetic, TimedMagneticModel, &GeoMagneticElements); /* Computes the geoMagnetic field elements and their time change*/
            MAG_CalculateGridVariation(CoordGeodetic, &GeoMagneticElements);
            MAG_PrintUserData(GeoMagneticElements, CoordGeodetic, UserDate, TimedMagneticModel, &Geoid); /* Print the results */
        }
        printf("\n\n Do you need more point data ? (y or n) \n ");
        fgets(ans, 20, stdin);
        switch(ans[0]) {
            case 'Y':
            case 'y':
                Flag = 1;
                break;
            case 'N':
            case 'n':
                Flag = 0;
                break;
            default:
                Flag = 0;
                break;
        }

    }


    MAG_FreeMagneticModelMemory(TimedMagneticModel);
    MAG_FreeMagneticModelMemory(MagneticModels[0]);

    return 0;
}