Update PRN numbers reference. Also PRNMAX definition.

1 files changed, 6 insertions, 5 deletions

diff --git a/gps.h b/gps.h
index 5bbd0a27..df433e96 100644
--- a/gps.h
+++ b/gps.h
@@ -40,7 +40,7 @@ extern "C" {
 #define GPSD_API_MINOR_VERSION	0	/* bump on compatible changes */
 
 #define MAXCHANNELS	72	/* must be > 12 GPS + 12 GLONASS + 2 WAAS */
-#define GPS_PRNMAX	32	/* above this number are SBAS satellites */
+#define GPS_PRNMAX	96	/* above this number are SBAS satellites */
 #define MAXUSERDEVS	4	/* max devices per user */
 #define GPS_PATH_MAX	128	/* for names like /dev/serial/by-id/... */
 
@@ -89,17 +89,18 @@ struct gps_fix_t {
 
 /*
  * Satellite ID classes.
- * IS-GPS-200 Revision E, paragraph 6.3.6
+ * IS-GPS-200 Revision H, paragraph 6.3.6
  */
 #define GPS_PRN(n)	(((n) >= 1) && ((n) <= 63))	/* U.S. GPS satellite */
-#define GBAS_PRN(n)	((n) >= 64 && ((n) <= 119))	/* Ground Based Augmentation System and other augmentation systems */
-#define SBAS_PRN(n)	((n) >= 120 && ((n) <= 158))	/* Satellite Based Augmentation System */
-#define GNSS_PRN(n)	((n) >= 159 && ((n) <= 210))	/* other Global Navigation Satellite System */
+#define GBAS_PRN(n)	((n) >= 64 && ((n) <= 119))	/* Other GNSS (GLONASS) and Ground Based Augmentation System (eg WAAS)*/
+#define SBAS_PRN(n)	((n) >= 120 && ((n) <= 158))	/* Satellite Based Augmentation System (eg GAGAN)*/
+#define GNSS_PRN(n)	((n) >= 159 && ((n) <= 210))	/* other GNSS (eg BeiDou) */
 
 /*
  * GLONASS birds reuse GPS PRNs.
  * it is a GPSD convention to map them to IDs 65..96.
  * (some other programs push them to 33 and above).
+ * The US GPS constellation plans to use the 33-63 range.
  */
 #define GLONASS_PRN_OFFSET	64