Split epe into eph and sep.

Try to do it with forward and backward compatibility, which is
challenging with current miscojson.

Sometimes epe was used to 2D estimated erro.  Sometimes for 3D error.
So make it explicit eph is 2D, and sep is 3D.

1 files changed, 9 insertions, 2 deletions

diff --git a/gps.h b/gps.h
index 23a97594..d8dd21bb 100644
--- a/gps.h
+++ b/gps.h
@@ -44,7 +44,9 @@ extern "C" {
  *       changed MAXCHANNELS
  * 8.0 - Change shape of rawdata_t.
  *       Added values for gps_data_t->status
- *       Move epe from gps_data_t to be near its friends in gps_fix_t.
+ *       Remove epe from gps_data_t, it duplicates gps_fix_t eph
+ *       Added sep (estimated spherical error, 3D)
+ *       Note: Some GPS call eph as epe, others call sep as epe
  */
 #define GPSD_API_MAJOR_VERSION	8	/* bump on incompatible changes */
 #define GPSD_API_MINOR_VERSION	0	/* bump on compatible changes */
@@ -106,7 +108,12 @@ struct gps_fix_t {
     double eps;		/* Speed uncertainty, meters/sec */
     double climb;       /* Vertical speed, meters/sec */
     double epc;		/* Vertical speed uncertainty */
-    double epe;         /* spherical position error, 95% confidence (meters) */
+    /* estimated postion error horizontal (2D) . meters, maybe 50%, maybe 95% */
+    /* aka estimated position error (epe) */
+    double eph;		/* estimated postion error horizontal (2D) */
+    /* sperical error probability, 3D. meters, maybe 50%, maybe 95% */
+    /* Garmin, not gpsd, calls this estimated position error (epe) */
+    double sep;
 
     double magnetic_track;  /* Course (relative to Magnetic North) */