+/** Miles per second to Knots */
+#define SG_MPS_TO_KT 1.9438444924406046432
+
+/** Knots to Miles per second */
+#define SG_KT_TO_MPS 0.5144444444444444444
+
+/** Miles per second to Miles per hour */
+#define SG_MPS_TO_MPH 2.2369362920544020312
+
+/** Miles per hour to Miles per second */
+#define SG_MPH_TO_MPS 0.44704
+
+/** Meters per second to Kilometers per hour */
+#define SG_MPS_TO_KMH 3.6
+
+/** Kilometers per hour to Miles per second */
+#define SG_KMH_TO_MPS 0.2777777777777777778
+
+/** Pascal to Inch Mercury */
+#define SG_PA_TO_INHG 0.0002952998330101010
+
+/** Inch Mercury to Pascal */
+#define SG_INHG_TO_PA 3386.388640341
+
+
+/** For divide by zero avoidance, this will be close enough to zero */