From d386b97b7e6fec77a301fac9993b7c862fc322c6 Mon Sep 17 00:00:00 2001 From: "Gary E. Miller" Date: Fri, 8 Mar 2019 15:25:13 -0800 Subject: NMEA doc: Clarify Mode indicator and GPGNS. --- www/NMEA.adoc | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) (limited to 'www') diff --git a/www/NMEA.adoc b/www/NMEA.adoc index d61f27e3..eb10cdd4 100644 --- a/www/NMEA.adoc +++ b/www/NMEA.adoc @@ -2,7 +2,7 @@ :description: A programmer's guide to NMEA0183, the GPS protocol reporting standard :keywords: NMEA0183, GPS, standard, protocol Eric S. Raymond -v2.23, Feb 2019 +v2.23, Mar 2019 NMEA 0183 is a proprietary protocol issued by the National Marine Electronics Association for use in boat navigation and control @@ -120,10 +120,12 @@ FAA Mode Indicator A = Autonomous mode D = Differential Mode E = Estimated (dead-reckoning) mode + F = RTK Float mode M = Manual Input Mode - S = Simulated Mode N = Data Not Valid P = Precise (4.00 and later) + R = RTK Integer mode + S = Simulated Mode This field may be empty. In pre-2.3 versions it is omitted. <> says that according to the NMEA specification, it dominates the Status field -- @@ -1134,18 +1136,18 @@ Field Number: V = Not valid for navigation 14. Checksum -The Mode indicator is two or more characters, with the first and second +The Mode indicator is one to four characters, with the first and second defined for GPS and GLONASS. Further characters may be defined. For each system, the character can have a value (table may be incomplete): -* N = Constellation not in use, or no valid fix * A = Autonomous (non-differential) * D = Differential mode -* P = Precise (no degradation, like Selective Availability) -* R = Real Time Kinematic -* F = Float RTK * E = Estimated (dead reckoning) Mode +* F = RTK Float * M = Manual Input Mode +* N = Constellation not in use, or no valid fix +* P = Precise (no degradation, like Selective Availability, and hires) +* R = RTK Integer * S = Simulator Mode Example: $GPGNS,112257.00,3844.24011,N,00908.43828,W,AN,03,10.5,,,,*57 -- cgit v1.2.1