GNSS-dat
gnss protocol - quectel_l76-lbl26-lblc86l_gnss_protocol_specification_v2-2.pdf
GSV - GNSS Satellites in View.
GSA - GNSS DOP and Active Satellites. GNSS receiver operating mode, satellites used in the navigation solution reported by the GGA sentence, and DOP values.
GLL - Geographic Position – Latitude/Longitude.
GGA - Global Positioning System Fix Data. Time, position, and fix-related data for a GNSS receiver.
VTG - Course Over Ground & Ground Speed.
RMC - Recommended Minimum Specific GNSS Data. Time, date, position, course, and speed data provided by a GNSS receiver.
GNSS Start
COLD start GNSS:
- When first used;
- Loss of ephemeris information due to battery depletion;
- Move the receiver more than 200 km under shutdown.
HOT start GNSS:
- Boot less than two hours from the last location
WARM start GNSS:
- Boot more than two hours from the last location
GNSS bands
| Type | Frequecy |
|---|---|
| GPS | 1575.42±1.023MHz |
| GLONASS | 1597.5~1605.8MHz |
| BeiDou | 1561.098±2.046MHz |
GNSS Antenna Requirements
| Antenna Specification | Specification Requirement |
|---|---|
| Operating Frequency Band | L1: 1559~1609MHz |
| Directionality | Hemisphere, face to sky |
| Impedance | 50 Ω |
| Maximum Input Power | 50W |
| VSWR | < 2 |
| Polarization Type | RHCP or Linear |
| Passive Antenna Gain | 0dBi |
| Active Antenna Gain | -2dBi |
| Active Antenna Noise Figure | < 1.5 |
| Built-in Antenna LNA Gain | 20dB(Typ.) |
| Total Antenna Gain | < 18 dB |
| Coaxial Cable Insertion Loss | <1.5dB |
Schematic
commands examples
Search GPS + GLONASS:
$PMTK353,1,1,0,0,0*2B
Enable GPS, Glonass, Galileo:
$PMTK353,1,1,1,0,0*2A
Sets the speed threshold for static navigation.
$PMTK386,0.4*39
$PMTK001,386,3*3D
Gets whether the GPS/GLONASS/BDS/Galileo satellite seraching is enabled or not.
$PMTK355*31
$PMTK001,355,3,1,1,0,0*33
PMTK838 PMTK_TEST_ANTI_SPOOFING - Enables or disables jamming detection function.
$PMTK838,1*2C
$PMTK001,838,3,1*2E
PMTK605 PMTK_Q_RELEASE - Queries the firmware release information. See PMTK_DT_RELEASE for the query result.
$PMTK605*31
$PMTK705,MT3333_AXN5.1.9_MODULE_STD_F1_P1,0007,Quectel-L76L,1.0*08
$PMTK705,AXN_5.1.6_3333_19010218,0007,Quectel-L76L,1.0*53