initial upload

lib/constants.c

@@ -0,0 +1,39 @@
+/*
+Define constants used, like the gravitational constant and unit conversions.
+
+All values are in SI units!
+*/
+
+#include "constants.h"
+
+/* Mean Earth radius [\f$ m \f$] */
+const double MEAN_EARTH_RADIUS = 6378137.0;
+
+/* The gravitational constant [\f$ m^3*kg^{-1}*s^{-1} \f$] */
+const double G = 0.00000000006673;
+
+/* Conversion factor from SI units to Eotvos
+[\f$ \frac{1}{s^2} = 10^9\ Eotvos \f$] */
+const double SI2EOTVOS = 1000000000.0;
+
+/* Conversion factor from SI units to mGal
+[\f$ 1 \frac{m}{s^2} = 10^5\ mGal \f$] */
+const double SI2MGAL = 100000.0;
+
+/* Pi */
+const double PI = 3.1415926535897932384626433832795;
+
+/* minimum distance-to-size ratio for potential computations to be accurate */
+const double TESSEROID_POT_SIZE_RATIO = 1;
+/* Minimum distance-to-size ratio for gravity computations to be accurate */
+const double TESSEROID_GX_SIZE_RATIO = 1.5;
+const double TESSEROID_GY_SIZE_RATIO = 1.5;
+const double TESSEROID_GZ_SIZE_RATIO = 1.5;
+/* Minimum distance-to-size ratio for gravity gradient computations to be
+accurate */
+const double TESSEROID_GXX_SIZE_RATIO = 8;
+const double TESSEROID_GXY_SIZE_RATIO = 8;
+const double TESSEROID_GXZ_SIZE_RATIO = 8;
+const double TESSEROID_GYY_SIZE_RATIO = 8;
+const double TESSEROID_GYZ_SIZE_RATIO = 8;
+const double TESSEROID_GZZ_SIZE_RATIO = 8;