Last change
on this file since 2623 was 2621, checked in by weber, 14 years ago |
NMEA string not fully compatible to standard
|
File size:
1.0 KB
|
Line | |
---|
1 | Todo's sorted by priority:
|
---|
2 |
|
---|
3 | BNS
|
---|
4 | =========================
|
---|
5 |
|
---|
6 | BNC
|
---|
7 | =========================
|
---|
8 | (1) NMEA GGA string is not fully compatible with the standard.
|
---|
9 | The following are observations by Tamas Horvath:
|
---|
10 | 1. Time tag should refer to UTC time and not GPS system time.
|
---|
11 | 2. Time tag format is hhmmss.ss and not hhmmss.
|
---|
12 | 3. The GPS Quality indicator field is 1 (GPS SPS Mode), which is correct, as
|
---|
13 | there is no category for PPP. In my opinion the NMEA protocol should be
|
---|
14 | extended by a new indicator number for PPP to make a clear difference between
|
---|
15 | autonomous GNSS and PPP.
|
---|
16 | 4. The HDOP value is constantly 2.0, which is obviously not real. I think this
|
---|
17 | field is filled with 2.0 as a default value in BNC.
|
---|
18 | 5. The Age of Differential GPS data field is not populated. I believe here the
|
---|
19 | age of RTCM SSR data should be put.
|
---|
20 | (2) BNC has a problem when the observation update rate is > 1Hz. Records get
|
---|
21 | mixed then in the RINEX files. A 10 Hz stream to test the situation is
|
---|
22 | available from GFZ caster 139.17.3.112:4080 through stream A17H.
|
---|
23 |
|
---|
24 | (3) GW: Keep an eye on www.igs-ip.net/PENC0.
|
---|
25 |
|
---|
Note:
See
TracBrowser
for help on using the repository browser.