PPP-howto: technical tweak. Reference Meridian, not Prime Meridian.

1 files changed, 3 insertions, 0 deletions

diff --git a/geoid.c b/geoid.c
index 3fb5a0a6..aaee40e0 100644
--- a/geoid.c
+++ b/geoid.c
@@ -1,6 +1,9 @@
 /*
  * geoid.c -- ECEF to WGS84 conversions, including ellipsoid-to-MSL height
  *
+ * This code does not specify, but given the creation date, I assume it
+ * is using the EGM96 geoid revised 2004.
+ *
  * Geoid separation code by Oleg Gusev, from data by Peter Dana.
  * ECEF conversion by Rob Janssen.
  *