Piksi® Multi and Duro with firmware v2.2 and newer is capable of sending base station data in RTCM v3.x format. This capability allows Piksi Multi and Duro to be used as a base station for another Piksi Multi / Duro and third-party RTK receivers.
The RTCM message details can be obtained from RTCM organization site: http://www.rtcm.org/
RTCM messages can be output via any available interface (UART, Ethernet, USB). RTCM versions 3.1 and 3.2 outputs are supported.
RTCM Output Modes
Piksi Multi and Duro can output RTCM v3 messages in three modes: Legacy, MSM4 and MSM5. The following messages are output in each mode:
Legacy: 1004, 1006, 1008, 1012, 1033 and 1230
MSM4: 1006, 1008, 1033, 1230 and MSM4 (1074, 1084, 1094, 1124)
MSM5: 1006, 1008, 1033, 1230 and MSM5 (1075, 1085, 1095, 1125)
In additionally to the output mode, users can specify antenna the height, antenna descriptor and receiver descriptor. The antenna descriptor and receiver descriptor strings are designed to conform to those specified in the “recvr_ant.tab” file published by the igs organization (ftp.igs.org/pub/station/general/rcvr_ant.tab).
Messages 1006, 1008, 1033 are sent at 1 Hz rate.
Messages 1004, 1012, MSM4, MSM5 are sent at SBP observations output rate (default 1 Hz).
Message 1230 is sent at 2 Hz rate.
1004 - GPS L1 and L2 observations
1006 - Stationary RTK reference station ARP with antenna height
1008 - Antenna descriptor
1012 - GLONASS L1 and L2 observations
1033 - Receiver and antenna descriptors
1074 - GPS pseudorange, phase range & CNR observables
1075 - GPS pseudorange, phase range, Doppler, & CNR observables
1084 - GLONASS pseudorange, phase range & CNR observables
1085 - GLONASS pseudorange, phase range, Doppler, & CNR observables
1094 - Galileo pseudorange, phase range & CNR observables
1095 - Galileo pseudorange, phase range, Doppler, & CNR observables
1124 - BeiDou pseudorange, phase range & CNR observables
1125 - BeiDou pseudorange, phase range, Doppler, & CNR observables
1230 - GLONASS L1 and L2 code-phase biases
RTCM Output Settings
To obtain complete base station RTCM output three groups of settings must be configured: RTCM output, antenna surveyed position and output port mode.
Select Show Advanced Settings checkbox to display the RTCM Output settings.
Fig. 1. Example of RTCMv3 output configuration
Configure RTCM Output as desired and click Save to Device button to make change permanent.
Note: Default antenna descriptor HXCGPS500 describes Swift-branded GPS500 mini-survey antenna included in evaluation and starter kits.
Fig. 2. Example of surveyed position configuration
Enter antenna’s surveyed location, set broadcast to True and click Save to Device button to make change permanent.
Note: If the surveyed position is not available, you can use Swift Console’s Auto Survey button (visible when receiver has a valid fix and any surveyed position settings in selected /clicked on). This will compute position based on an average of the last 1000 position solutions and therefore not as accurate as a proper survey of the base station location. For additional details refer to Piksi Multi - GNSS RTK Position with Stationary Base article.
Output Port Mode
Fig. 3. Example of RTCMv3 output enabled on UART0
Select RTCMv3 OUT on desired port mode and click Save to Device button to make change permanent.
- When RTCMv3 output is selected any input data on the port will be ignored.
- Ethernet connectivity is provided through the TCP or UDP servers and clients.
- Piksi Multi / Duro cannot act as an NTRIP server or caster.