Internal comment on dmtlog elevation oddity.

diff --git a/dmtlog.c b/dmtlog.c
index 22f2a56e64e43cdd318cd732b2a5ff027b00ba19..5de0fa09261c5be966708c253866b4f9af16d0bd 100644 (file)
--- a/dmtlog.c
+++ b/dmtlog.c
@@ -128,6 +128,15 @@ finalize_pt(waypoint *wpt)
                wpt->latitude = xmlLatitude;
                wpt->longitude = xmlLongitude;
        }
+       /* NOTE:
+        * Alan White reports this program actually subtracts a number
+        * of meters ranging between 46 and 50 meters.  It appears to be
+        * constant for each location, but different without an obvious
+        * correlation to ground altitude.  We considered offsetting this
+        * in GPSBabel, but concluded it wasn't worth the bother. 
+        * If we get complaints, probably all of our alt reading and writing
+        * should offset an average of 46m or so.
+        */
        wpt->altitude = xmlAltitude;
        convert_datum(wpt, xmldatum);
 }