update README

plantbreeding · Apr 19, 2018 · 65eca09 · 65eca09
1 parent b1e264a
commit 65eca09
Showing 1 changed file with 9 additions and 7 deletions.
diff --git a/Specification/README.md b/Specification/README.md
@@ -204,17 +204,19 @@ Timestamp UTC|yyyy-MM-ddThh:mm:ssZ|2017-06-16T20:47:23Z
 
 ### Location coordinate encoding
 
-To encode locations as coordinates, the ISO 6709 standard is used, degree notation only.
+To encode locations as coordinates, the ISO 6709 standard is used, degree notation only. WGS84 is used as the geodetic datum spatial reference system.
 
-||Format|Example|
-|---|---|---|
-|latitude|±DD.D|"+40.20361"|
-|longitude|±DDD.D|"-075.00417"|
+||Unit|Format|Example|
+|---|---|---|---|
+|latitude|degrees|±DD.D|"+40.20361"|
+|longitude|degrees|±DDD.D|"-075.00417"|
+|altitude|meters|±M|"+127"|
 
 Note:
  + Plus and minus signs are always required
- + Latitude has two digits before the decimal separator (with leading zeroes when necessary)
- + Longitude has three digits before the decimal separator (with leading zeroes when necessary)
+ + Latitude has two digits before the decimal separator (with leading zeros when necessary)
+ + Longitude has three digits before the decimal separator (with leading zeros when necessary)
+ + Altitude is recorded in meters above the WGS84 reference ellipsoid (no leading zeros) 
 
 
 ### Search Services