ROSaic = ROS + mosaic

Overview

This repository hosts a ROS Melodic and Noetic driver (i.e. for Linux only) - written in C++ - that works with mosaic and AsteRx - two of Septentrio's cutting-edge GNSS/INS receiver families - and beyond. Since Noetic will only be supported until 2025, a ROS2 version is available in the branch ros2.

Main Features: - Supports Septentrio's single antenna GNSS, dual antenna GNSS and INS receivers - Supports serial, TCP/IP and USB connections, the latter being compatible with both serial (RNDIS) and TCP/IP protocols - Supports several ASCII (including key NMEA ones) messages and SBF (Septentrio Binary Format) blocks - Can publish nav_msgs/Odometry message for INS receivers - Can blend SBF blocks PVTGeodetic, PosCovGeodetic, ChannelStatus, MeasEpoch, AttEuler, AttCovEuler, VelCovGeodetic and DOP in order to publish gps_common/GPSFix and sensor_msgs/NavSatFix messages - Supports axis convention conversion as Septentrio follows the NED convention, whereas ROS is ENU. - Easy configuration of multiple RTK corrections simultaneously (via NTRIP, TCP/IP stream, or serial) - Can play back PCAP capture logs for testing purposes - Tested with the mosaic-X5, mosaic-H, AsteRx-m3 Pro+ and the AsteRx-SBi3 Pro receiver - Easy to add support for more log types

Please let the maintainers know of your success or failure in using the driver with other devices so we can update this page appropriately.

Dependencies

The master branch for this driver functions on both ROS Melodic (Ubuntu 18.04) and Noetic (Ubuntu 20.04). It is thus necessary to install the ROS version that has been designed for your Linux distro.

Additional ROS packages have to be installed for the GPSFix message.

sudo apt install ros-$ROS_DISTRO-nmea-msgs ros-$ROS_DISTRO-gps-common.

The serial and TCP/IP communication interface of the ROS driver is established by means of the Boost C++ library. In the unlikely event that the below installation instructions fail to install Boost on the fly, please install the Boost libraries via

sudo apt install libboost-all-dev.

Compatiblity with PCAP captures are incorporated through pcap libraries. Install the necessary headers via

sudo apt install libpcap-dev.

Conversions from LLA to UTM are incorporated through GeographicLib. Install the necessary headers via

sudo apt install libgeographic-dev

Usage

Inertial Navigation System (INS): Basics

• An Inertial Navigation System (INS) is a device which takes the rotation and acceleration solutions as obtained from its Inertial Measurement Unit (IMU) and combines those with position and velocity information from the GNSS module. Compared to a GNSS system with 7D or 8D (dual-antenna systems) phase space solutions, the combined, Kalman-filtered 9D phase space solution (3 for position, 3 for velocity, 3 for orientation) of an INS is more accurate, more precise and more stable against GNSS outages.

• The IMU is typically made up of a 3-axis accelerometer, a 3-axis gyroscope and sometimes a 3-axis magnetometer and measures the system's angular rate and acceleration.

  Measure and Compensate for IMU-Antenna Lever Arm
  • The IMU-antenna lever-arm is the relative position between the IMU reference point and the GNSS Antenna Reference Point (ARP), measured in the vehicle frame.
  • In case of AsteRx SBi3, the IMU reference point is clearly marked on the top panel of the receiver. It is important to compensate for the effect of the lever arm, otherwise the receiver may not be able to calculate an accurate INS position.
  • The IMU/antenna position can be changed by specifying the lever arm's x,yand z parameters in the config.yaml file under the ins_spatial_config/ant_lever_arm parameter.

  

  Compensate for IMU Orientation

  + It is important to take into consideration the mounting direction of the IMU in the body frame of the vehicle. For e.g. when the receiver is installed horizontally with the front panel facing the direction of travel, we must compensate for the IMU’s orientation to make sure the IMU reference frame is aligned with the vehicle reference frame. The IMU position and orientation is printed on the top panel, cf. image below. + The IMU's orientation can be changed by specifying the orientation angles theta_x,theta_yand theta_z in the config.yaml file under the ins_spatial_config/imu_orientation + The below image illustrates the orientation of the IMU reference frame with the associated IMU orientation for the depicted installation. Note that for use_ros_axis_orientation: true sensor_default is the top left position.

  

• These Steps should be followed to configure the receiver in INS integration mode:

  • Specify receiver_type: ins
  • Specify the orientation of the IMU sensor with respect to your vehicle, using the ins_spatial_config/imu_orientation parameter.
  • Specify the IMU-antenna lever arm in the vehicle reference frame. This is the vector starting from the IMU reference point to the ARP of the main GNSS antenna. This can be done by means of the ins_spatial_config/ant_lever_arm parameter. Specify ins_spatial_config/vsm_lever_arm if measurements of a velocity sensor is available.
  • Alternatively the lever arms may be specified via tf. Set get_spatial_config_from_tfto true in this case.
  • If the point of interest is neither the IMU nor the ARP of the main GNSS antenna, the vector between the IMU and the point of interest can be provided with the ins_solution/poi_lever_arm parameter.

• NOTE: This driver will always overwrite the previous value of the above mentioned parameters, also if the value is left to zero in the "yaml" file.

• For further more information about Septentrio receivers, visit Septentrio support resources or check out the user manual and reference guide of the AsteRx SBi3 receiver.

ROSaic Parameters

The following is a list of ROSaic parameters found in the config/rover.yaml file. * Parameters Configuring Communication Ports and Processing of GNSS and INS Data

• device: location of device connection
  • serial:xxx format for serial connections, where xxx is the device node, e.g. serial:/dev/ttyUSB0
  • file_name:path/to/file.sbf format for publishing from an SBF log
  • file_name:path/to/file.pcap format for publishing from PCAP capture.
    • Regarding the file path, ROS_HOME=`pwd` in front of roslaunch septentrio... might be useful to specify that the node should be started using the executable's directory as its working-directory.
  • tcp://host:port format for TCP/IP connections
    • 28784 should be used as the default (command) port for TCP/IP connections. If another port is specified, the receiver needs to be (re-)configured via the Web Interface before ROSaic can be used.
    • An RNDIS IP interface is provided via USB, assigning the address 192.168.3.1 to the receiver. This should work on most modern Linux distributions. To verify successful connection, open a web browser to access the web interface of the receiver using the IP address 192.168.3.1.
  • default: tcp://192.168.3.1:28784
• serial: specifications for serial communication
  • baudrate: serial baud rate to be used in a serial connection. Ensure the provided rate is sufficient for the chosen SBF blocks. For example, activating MeasEpoch (also necessary for /gpsfix) may require up to almost 400 kBit/s.
  • rx_serial_port: determines to which (virtual) serial port of the Rx we want to get connected to, e.g. USB1 or COM1
  • hw_flow_control: specifies whether the serial (the Rx's COM ports, not USB1 or USB2) connection to the Rx should have UART HW flow control enabled or not
    • off to disable UART HW flow control, RTS|CTS to enable it
  • default: 921600, USB1, off
• login: credentials for user authentication to perform actions not allowed to anonymous users. Leave empty for anonymous access.
  • user: user name
  • password: password

• receiver_type: This parameter is to select the type of the Septentrio receiver
  • gnss for GNSS receivers.
  • ins for INS receivers.
  • ins_in_gnss_mode INS receivers in GNSS mode.
  • default: gnss
    
• multi_antenna: Whether or not the Rx has multiple antennas.
  • default: false

• frame_id: name of the ROS tf frame for the Rx, placed in the header of published GNSS messages. It corresponds to the frame of the main antenna.
  • In ROS, the tf package lets you keep track of multiple coordinate frames over time. The frame ID will be resolved by tf_prefix if defined. If a ROS message has a header (all of those we publish do), the frame ID can be found via rostopic echo /topic, where /topic is the topic into which the message is being published.
  • default: gnss
• imu_frame_id: name of the ROS tf frame for the IMU, placed in the header of published IMU message
  • default: imu
• poi_frame_id: name of the ROS tf frame for the POI, placed in the child frame_id of localization if ins_use_poi is set to true.
  • default: base_link
• vsm_frame_id: name of the ROS tf frame for the velocity sensor.
  • default: vsm
• aux1_frame_id: name of the ROS tf frame for the aux1 antenna.
  • default: aux1
• vehicle_frame_id: name of the ROS tf frame for the vehicle. Default is the same as poi_frame_id but may be set otherwise.
  • default: base_link
• local_frame_id: name of the ROS tf frame for the local frame.
  • default: odom
• insert_local_frame: Wether to insert a local frame to published tf according to ROS REP 105. The transform from the local frame specified by local_frame_id to the vehicle frame specified by vehicle_frame_id has to be provided, e.g. by odometry. Insertion of the local frame means the transform between local frame and global frame is published instead of transform between vehicle frame and global frame.
  • default: false
• get_spatial_config_from_tf: wether to get the spatial config via tf with the above mentioned frame ids. This will override spatial settings of the config file. For receiver type ins with multi_antenna set to true all frames have to be provided, with multi_antenna set to false, aux1_frame_id is not necessary. For type gnss with dual-antenna setup only frame_id, aux1_frame_id, and poi_frame_id are needed. For single-antenna gnss no frames are needed. Keep in mind that tf has a tree structure. Thus, poi_frame_id is the base for all mentioned frames.
  • default: false
• use_ros_axis_orientation Wether to use ROS axis orientations according to ROS REP 103 for body related frames and geographic frames. Body frame directions affect INS lever arms and IMU orientation setup parameters. Geographic frame directions affect orientation Euler angles for INS+GNSS and attitude of dual-antenna GNSS. If use_ros_axis_orientation is set to true, the driver converts between the NED convention (Septentrio: yaw = 0 is north, positive clockwise), and ENU convention (ROS: yaw = 0 is east, positive counterclockwise). There is no conversion when setting this parameter to false and the angles will be consistent with the web GUI in this case.
  • If set to false Septentrios definition is used, i.e., front-right-down body related frames and NED (north-east-down) for orientation frames.
  • If set to true ROS definition is used, i.e., front-left-up body related frames and ENU (east-north-up) for orientation frames.
  • default: true

• lock_utm_zone: wether the UTM zone of the initial localization is locked, i.e., this zone is kept even if a zone transition would occur.
  • default: true

• datum: With this command, the datum the coordinates should refer to is selected. With setting it to Default, the datum depends on the positioning mode, e.g. WGS84 for standalone positioning.
  • Since the standardized GGA message does only provide the orthometric height (= MSL height = distance from Earth's surface to geoid) and the geoid undulation (distance from geoid to ellipsoid) for which non-WGS84 datums cannot be specified, it does not affect the GGA message.
  • default: Default

• poi_to_arp: offsets of the main GNSS antenna reference point (ARP) with respect to the point of interest (POI = marker). Use for static receivers only.
  • The parameters delta_e, delta_n and delta_u are the offsets in the East, North and Up (ENU) directions respectively, expressed in meters.
  • All absolute positions reported by the receiver are POI positions, obtained by subtracting this offset from the ARP. The purpose is to take into account the fact that the antenna may not be located directly on the surveying POI.
  • default: 0.0, 0.0 and 0.0

+ `att_offset`: Angular offset between two antennas (Main and Aux) and vehicle frame
+ `heading`: The perpendicular (azimuth) axis can be compensated for by adjusting the `heading` parameter
+ `pitch`: Vertical (elevation) offset can be compensated for by adjusting the `pitch` parameter
+ default: `0.0`, `0.0` (degrees)

• ant_type: type of your main GNSS antenna
  • For best positional accuracy, it is recommended to select a type from the list returned by the command lstAntennaInfo, Overview. This is the list of antennas for which the receiver can compensate for phase center variation.
  • By default and if ant_type does not match any entry in the list returned by lstAntennaInfo, Overview, the receiver will assume that the phase center variation is zero at all elevations and frequency bands, and the position will not be as accurate.
  • default: Unknown
• ant_serial_nr: serial number of your main GNSS antenna
• ant_aux1_type and ant_aux1_serial_nr: same for Aux1 antenna

• leap_seconds: Leap seconds are automatically gathered from the receiver via the SBF block ReceiverTime. If a log file is used for simulation and this block was not recorded, the number of leap seconds that have been inserted up until the point of ROSaic usage can be set by this parameter.
  • At the time of writing the code (2020), the GPS time, which is unaffected by leap seconds, was ahead of UTC time by 18 leap seconds. Adapt the leap_seconds parameter accordingly as soon as the next leap second is inserted into the UTC time or in case you are using ROSaic for the purpose of simulations.

• polling_period/pvt: desired period in milliseconds between the polling of two consecutive PVTGeodetic, PosCovGeodetic, PVTCartesian and PosCovCartesian blocks and - if published - between the publishing of two of the corresponding ROS messages (e.g. septentrio_gnss_driver/PVTGeodetic.msg). Consult firmware manual for allowed periods. If the period is set to a lower value than the receiver is capable of, it will be published with the next higher period. If set to 0, the SBF blocks are output at their natural renewal rate (OnChange).
  • Clearly, the publishing of composite ROS messages such as sensor_msgs/NavSatFix.msg or gps_common/GPSFix.msg is triggered by the SBF block that arrives last among the blocks of the current epoch.
  • default: 500 (2 Hz)
• polling_period/rest: desired period in milliseconds between the polling of all other SBF blocks and NMEA sentences not addressed by the previous parameter, and - if published - between the publishing of all other ROS messages
  • default: 500 (2 Hz)

• use_gnss_time: true if the ROS message headers' unix epoch time field shall be constructed from the TOW/WNC (in the SBF case) and UTC (in the NMEA case) data, false if those times shall be taken by the driver from ROS time. If use_gnss_time is set to true, make sure the ROS system is synchronized to an NTP time server either via internet or ideally via the Septentrio receiver since the latter serves as a Stratum 1 time server not dependent on an internet connection. The NTP server of the receiver is automatically activated on the Septentrio receiver (for INS/GNSS a firmware >= 1.3.3 is needed).
  • default: true

• rtk_settings: determines RTK connection parameters
  • There are multiple possibilities to feed RTK corrections to the Rx. They may be set simultaneously and the Rx will choose the nearest source.
    • a) ntrip_# if the Rx has internet access and is able to receieve NTRIP streams from a caster. Up to three NTRIP connections are possible.
    • b) ip_server_# if corrections are to be receieved via TCP/IP for example over Data Link from Septentrio's RxTools is installed on a computer. Up to five IP server connections are possible.
    • c) serial_# if corrections are to be receieved via a serial port for example over radio link from a local RTK base or over Data Link from Septentrio's RxTools installed on a computer. Up to five serial connections are possible.
  • ntrip_#: for receiving corretions from an NTRIP caster (# is from 1 ... 3).
    • id: NTRIP connection NTR1, NTR2, or NTR3.
    • default: ""
    • caster: is the hostname or IP address of the NTRIP caster to connect to.
    • default: ""
    • caster_port: IP port of the NTRIP caster.
    • default: 2021
    • username: user name for the NTRIP caster.
    • default: ""
    • pasword: password for the NTRIP caster. The receiver encrypts the password so that it cannot be read back with the command "getNtripSettings".
    • default: ""
    • mountpoint: mount point of the NTRP caster to be used.
    • default: ""
    • version: argument specifies which version of the NTRIP protocol to use (v1 or v2).
    • default: "v2"
    • tls: determines wether to use TLS.
    • default: false
    • fingerprint: fingerprint to be used if the certificate is self-signed. If the caster’s certificate is known by a publicly-trusted certification authority, fingerprint should be left empty.
    • default: ""
    • rtk_standard: determines the RTK standard, options are auto, RTCMv2, RTCMv3, or CMRv2.
    • default: "auto"
    • send_gga: specifies whether or not to send NMEA GGA messages to the NTRIP caster, and at which rate. It must be one of auto, off, sec1, sec5, sec10 or sec60. In auto mode, the receiver automatically sends GGA messages if requested by the caster.
    • default: "auto"
    • keep_open: determines wether this connection shall be kept open. If set to true the Rx will still be able to receive RTK corrections to improve precision after driver is shut down.
    • default: true
  • ip_server_#: for receiving corretions via TCP/IP (# is from 1 ... 5).
    • id: specifies the IP server IPS1, IPS2, IPS3, IPS4, or IPS5. Note that ROSaic will send GGA messages on this connection if send_gga is set, such that in the Data Link application of RxTools one just needs to set up a TCP client to the host name as found in the ROSaic parameter device with the port as found in port. If the latter connection were connection 1 on Data Link, then connection 2 would set up an NTRIP client connecting to the NTRIP caster as specified in the above parameters in order to forward the corrections from connection 2 to connection 1.
    • default: ""
      
    • port: its port number of the connection that ROSaic establishes on the receiver. When selecting a port number, make sure to avoid conflicts with other services.
    • default: 0
    • rtk_standard: determines the RTK standard, options are auto, RTCMv2, RTCMv3, or CMRv2.
    • default: ""
    • send_gga: specifies whether or not to send NMEA GGA messages to the NTRIP caster, and at which rate. It must be one of auto, off, sec1, sec5, sec10 or sec60. In auto mode, the receiver sends with sec1.
    • default: "auto"
    • keep_open: determines wether this connection shall be kept open. If set to true the Rx will still be able to receive RTK corrections to improve precision after driver is shut down.
    • default: true
  • serial_#: for receiving corretions via serial connection (# is from 1 ... 5).
    • port: Serial connection COM1, COM2, COM3, USB1, or USB2 on which corrections could be forwarded to the Rx from a serially connected radio link modem or via Data Link for example.
    • default: ""
    • baud_rate: sets the baud rate of this port for genuine serial ports, i.e., not relevant for USB connection.
    • default: 115200
    • rtk_standard: determines the RTK standard, options are auto, RTCMv2, RTCMv3, or CMRv2.
    • default: "auto"
    • send_gga: specifies whether or not to send NMEA GGA messages to the NTRIP caster, and at which rate. It must be one of auto, off, sec1, sec5, sec10 or sec60. In auto mode, the receiver sends with sec1.
    • default: "auto"
    • keep_open: determines wether this connection shall be kept open. If set to true the Rx will still be able to receive RTK corrections to improve precision after driver is shut down.
    • default: true

+ `ins_spatial_config`: Spatial configuration of INS/IMU. Coordinates according to vehicle related frame directions chosen by `use_ros_axis_orientation` (front-left-up if `true` and front-right-down if `false`).
  + `imu_orientation`: IMU sensor orientation
    + Parameters `theta_x`, `theta_y` and `theta_z` are used to determine the sensor orientation with respect to the vehicle frame. Positive angles correspond to a right-handed (clockwise) rotation of the IMU with respect to its nominal orientation (see below). The order of the rotations is as follows: `theta_z` first, then `theta_y`, then `theta_x`.
    + The nominal orientation is where the IMU is upside down and with the `X axis` marked on the receiver pointing to the front of the vehicle. By contrast, for `use_ros_axis_orientation: true`, nominal orientation is where the `Z axis` of the IMU is pointing upwards and also with the `X axis` marked on the receiver pointing to the front of the vehicle.
    + default: `0.0`, `0.0`, `0.0` (degrees)
  + `poi_lever_arm`: The lever arm from the IMU reference point to a user-defined POI
    + Parameters `delta_x`,`delta_y` and `delta_z` refer to the vehicle reference frame
    + default: `0.0`, `0.0`, `0.0` (meters)
  + `ant_lever_arm`: The lever arm from the IMU reference point to the main GNSS antenna
    + The parameters `x`,`y` and `z` refer to the vehicle reference frame
    + default: `0.0`, `0.0`, `0.0` (meters)
  + `vsm_lever_arm`: The lever arm from the IMU reference point to the velocity sensor
    + The parameters `vsm_x`,`vsm_y` and `vsm_z` refer to the vehicle reference frame 
    + default: `0.0`, `0.0`, `0.0` (meters)
+ `ins_initial_heading`: How the receiver obtains the initial INS/GNSS integrated heading during the alignment phase
    + In case it is `auto`, the initial integrated heading is determined from GNSS measurements.
    + In case it is `stored`, the last known heading when the vehicle stopped before switching off the receiver is used as initial heading. Use if vehicle does not move when the receiver is switched off.
    + default: `auto`
+ `ins_std_dev_mask`: Maximum accepted error
  + `att_std_dev`: Configures an output limit on standard deviation of the attitude angles (max error accepted: 5 degrees)
  + `pos_std_dev`: Configures an output limit on standard deviation of the position (max error accepted: 100 meters)
  + default: `5` degrees, `10` meters    
+ `ins_use_poi`: Whether or not to use the POI defined in `ins_spatial_config/poi_lever_arm`
  + If true, the point at which the INS navigation solution (e.g. in `insnavgeod` ROS topic) is calculated will be the POI as defined above (`poi_frame_id`), otherwise it'll be the main GNSS antenna (`frame_id`). Has to be set to `true` if tf shall be published.
  + default: `true`
+ `ins_vsm`: Configuration of the velocity sensor measurements.
  + `ros`: VSM info received from ROS msgs
    + `source`: Specifies which ROS message type shall be used, options are `odometry`or `twist`. Accordingly, a subscriber is established of the type [`nav_msgs/Odometry.msg`](https://docs.ros.org/en/api/nav_msgs/html/msg/Odometry.html) or [`geometry_msgs/TwistWithCovarianceStamped.msg`](https://docs.ros.org/en/api/sensor_msgs/html/msg/TwistWithCovarianceStamped.html) listening on the topics `odometry_vsm` or `twist_vsm` respectively. Only linear velocities are evaluated. Measurements have to be with respect to the frame aligned with the vehicle and defined by `ins_spatial_config.vsm_lever_arm` or tf-frame `vsm_frame_id`, see also comment in [`nav_msgs/Odometry.msg`](https://docs.ros.org/en/api/nav_msgs/html/msg/Odometry.html) that twist should be specified in `child_frame_id`.
      + default: ""
    + `config`: Defines which measurements belonging to the respective axes are forwarded to the INS. In addition, non-holonomic constraints may be introduced for directions known to be restricted in movement. For example, a vehicle with Ackermann steering is limited in its sidewards and upwards movement. So, even if only motion in x-direction may be measured, zero-velocities for y and z may be sent.
      + default: []
    + `variances_by_parameter`: Wether variances shall be entered by parameter `ins_vsm/ros/variances` or the values inside the messaged are used.
      + default: false
    + `variances`: Variances of the respective axes. Only have to be set if `ins_vsm/ros/variances_by_parameter` is set to `true`. Values must be > 0.0, else measurements cannot not be used. 
      + default: []
  + `ip_server`:
    + `id`: IP server to receive the VSM info (e.g. `IPS2`).
        + default: ""
    + `port`: TCP port to receive the VSM info. When selecting a port number, make sure to avoid conflicts with other services.
      + default: 0
    + `keep_open` determines wether this connections to receive VSM shall be kept open on driver shutdown. If set to `true` the Rx will still be able to use external VSM info to improve its localization.
      + default: `true`
  + `serial`:
    + `port`: Serial port to receive the VSM info.
      + default: ""
    + `baud_rate`: Baud rate of the serial port to receive the VSM info.
      + default: 115200
    + `keep_open` determines wether this connections to receive VSM shall be kept open on driver shutdown. If set to `true` the Rx will still be able to use external VSM info to improve its localization.
      + default: `true`

+ `activate_debug_log`: `true` if ROS logger level shall be set to debug.

• Parameters Configuring Publishing of ROS Messages

  NMEA/SBF Messages to be Published
  • publish/gpgga: true to publish nmea_msgs/GPGGA.msg messages into the topic /gpgga
  • publish/gprmc: true to publish nmea_msgs/GPRMC.msg messages into the topic /gprmc
  • publish/gpgsa: true to publish nmea_msgs/GPGSA.msg messages into the topic /gpgsa
  • publish/gpgsv: true to publish nmea_msgs/GPGSV.msg messages into the topic /gpgsv
  • publish/measepoch: true to publish septentrio_gnss_driver/MeasEpoch.msg messages into the topic /measepoch
  • publish/pvtcartesian: true to publish septentrio_gnss_driver/PVTCartesian.msg messages into the topic /pvtcartesian
  • publish/pvtgeodetic: true to publish septentrio_gnss_driver/PVTGeodetic.msg messages into the topic /pvtgeodetic
  • publish/basevectorcart: true to publish septentrio_gnss_driver/BaseVectorCart.msg messages into the topic /basevectorcart
  • publish/basevectorgeod: true to publish septentrio_gnss_driver/BaseVectorGeod.msg messages into the topic /basevectorgeod
  • publish/poscovcartesian: true to publish septentrio_gnss_driver/PosCovCartesian.msg messages into the topic /poscovcartesian
  • publish/poscovgeodetic: true to publish septentrio_gnss_driver/PosCovGeodetic.msg messages into the topic /poscovgeodetic
  • publish/velcovgeodetic: true to publish septentrio_gnss_driver/VelCovGeodetic.msg messages into the topic /velcovgeodetic
  • publish/atteuler: true to publish septentrio_gnss_driver/AttEuler.msg messages into the topic /atteuler
  • publish/attcoveuler: true to publish septentrio_gnss_driver/AttCovEuler.msg messages into the topic /attcoveuler
  • publish/gpst: true to publish sensor_msgs/TimeReference.msg messages into the topic /gpst
  • publish/navsatfix: true to publish sensor_msgs/NavSatFix.msg messages into the topic /navsatfix
  • publish/gpsfix: true to publish gps_common/GPSFix.msg messages into the topic /gpsfix
  • publish/pose: true to publish geometry_msgs/PoseWithCovarianceStamped.msg messages into the topic /pose
  • publish/twist: true to publish geometry_msgs/TwistWithCovarianceStamped.msg messages into the topics /twist and /twist_ins respectively
  • publish/diagnostics: true to publish diagnostic_msgs/DiagnosticArray.msg messages into the topic /diagnostics
  • publish/insnavcart: true to publish septentrio_gnss_driver/INSNavCart.msg message into the topic/insnavcart
  • publish/insnavgeod: true to publish septentrio_gnss_driver/INSNavGeod.msg message into the topic/insnavgeod
    
  • publish/extsensormeas: true to publish septentrio_gnss_driver/ExtSensorMeas.msg message into the topic/extsensormeas
  • publish/imusetup: true to publish septentrio_gnss_driver/IMUSetup.msg message into the topic/imusetup
  • publish/velsensorsetup: true to publish septentrio_gnss_driver/VelSensorSetup.msgs message into the topic/velsensorsetup
  • publish/exteventinsnavcart: true to publish septentrio_gnss_driver/ExtEventINSNavCart.msgs message into the topic/exteventinsnavcart
  • publish/exteventinsnavgeod: true to publish septentrio_gnss_driver/ExtEventINSNavGeod.msgs message into the topic/exteventinsnavgeod
  • publish/imu: true to publish sensor_msgs/Imu.msg message into the topic/imu
  • publish/localization: true to publish nav_msgs/Odometry.msg message into the topic/localization
  • publish/tf: true to broadcast tf of localization. ins_use_poi must also be set to true to publish tf.

ROS Topic Publications

A selection of NMEA sentences, the majority being standardized sentences, and proprietary SBF blocks is translated into ROS messages, partly generic and partly custom, and can be published at the discretion of the user into the following ROS topics. All published ROS messages, even custom ones, start with a ROS generic header std_msgs/Header.msg, which includes the receiver time stamp as well as the frame ID, the latter being specified in the ROS parameter frame_id.

• /gpgga: publishes nmea_msgs/Gpgga.msg - converted from the NMEA sentence GGA.
• /gprmc: publishes nmea_msgs/Gprmc.msg - converted from the NMEA sentence RMC.
• /gpgsa: publishes nmea_msgs/Gpgsa.msg - converted from the NMEA sentence GSA.
• /gpgsv: publishes nmea_msgs/Gpgsv.msg - converted from the NMEA sentence GSV.
• /measepoch: publishes custom ROS message septentrio_gnss_driver/MeasEpoch.msg, corresponding to the SBF block MeasEpoch.
• /pvtcartesian: publishes custom ROS message septentrio_gnss_driver/PVTCartesian.msg, corresponding to the SBF block PVTCartesian (GNSS case) or INSNavGeod (INS case).
• /pvtgeodetic: publishes custom ROS message septentrio_gnss_driver/PVTGeodetic.msg, corresponding to the SBF block PVTGeodetic (GNSS case) or INSNavGeod (INS case).
• /basevectorcart: publishes custom ROS message septentrio_gnss_driver/BaseVectorCart.msg, corresponding to the SBF block BaseVectorCart.
• /basevectorgeod: publishes custom ROS message septentrio_gnss_driver/BaseVectorGeod.msg, corresponding to the SBF block BaseVectorGeod.
• /poscovcartesian: publishes custom ROS message septentrio_gnss_driver/PosCovCartesian.msg, corresponding to SBF block PosCovCartesian (GNSS case) or INSNavGeod (INS case).
• /poscovgeodetic: publishes custom ROS message septentrio_gnss_driver/PosCovGeodetic.msg, corresponding to SBF block PosCovGeodetic (GNSS case) or INSNavGeod (INS case).
• /velcovgeodetic: publishes custom ROS message septentrio_gnss_driver/VelCovGeodetic.msg, corresponding to SBF block VelCovGeodetic (GNSS case).
• /atteuler: publishes custom ROS message septentrio_gnss_driver/AttEuler.msg, corresponding to SBF block AttEuler.
• /attcoveuler: publishes custom ROS message septentrio_gnss_driver/AttCovEuler.msg, corresponding to the SBF block AttCovEuler.
• /gpst (for GPS Time): publishes generic ROS message sensor_msgs/TimeReference.msg, converted from the PVTGeodetic (GNSS case) or INSNavGeod (INS case) block's GPS time information, stored in its header, or - if use_gnss_time is set to false - from the systems's wall-clock time.
• /navsatfix: publishes generic ROS message sensor_msgs/NavSatFix.msg, converted from the SBF blocks PVTGeodetic,PosCovGeodetic (GNSS case) or INSNavGeod (INS case).
  • The ROS message sensor_msgs/NavSatFix.msg can be fed directly into the navsat_transform_node of the ROS navigation stack.
• /gpsfix: publishes generic ROS message gps_msgs/GPSFix.msg, which is much more detailed than sensor_msgs/NavSatFix.msg, converted from the SBF blocks PVTGeodetic, PosCovGeodetic, ChannelStatus, MeasEpoch, AttEuler, AttCovEuler, VelCovGeodetic, DOP (GNSS case) or INSNavGeod, DOP (INS case).
• /pose: publishes generic ROS message geometry_msgs/PoseWithCovarianceStamped.msg, converted from the SBF blocks PVTGeodetic, PosCovGeodetic, AttEuler, AttCovEuler (GNSS case) or INSNavGeod (INS case).
  • Note that GNSS provides absolute positioning, while robots are often localized within a local level cartesian frame. The pose field of this ROS message contains position with respect to the absolute ENU frame (longitude, latitude, height), i.e. not a cartesian frame, while the orientation is with respect to a vehicle-fixed (e.g. for mosaic-x5 in moving base mode via the command setAttitudeOffset, ...) !local! NED frame or ENU frame if use_ros_axis_directions is set true. Thus the orientation is !not! given with respect to the same frame as the position is given in. The cross-covariances are hence set to 0.
• /twist: publishes generic ROS message geometry_msgs/TwistWithCovarianceStamped.msg, converted from the SBF blocks PVTGeodetic and VelCovGeodetic.
• /twist_ins: publishes generic ROS message geometry_msgs/TwistWithCovarianceStamped.msg, converted from SBF block INSNavGeod.
• /insnavcart: publishes custom ROS message septentrio_gnss_driver/INSNavCart.msg, corresponding to SBF block INSNavCart.
• /insnavgeod: publishes custom ROS message septentrio_gnss_driver/INSNavGeod.msg, corresponding to SBF block INSNavGeod.
• /extsensormeas: publishes custom ROS message septentrio_gnss_driver/ExtSensorMeas.msg, corresponding to SBF block ExtSensorMeas.
• /imusetup: publishes custom ROS message septentrio_gnss_driver/IMUSetup.msg, corresponding to SBF block IMUSetup.
• /velsensorsetup: publishes custom ROS message septentrio_gnss_driver/VelSensorSetup.msg corresponding to SBF block VelSensorSetup.
• /exteventinsnavcart: publishes custom ROS message septentrio_gnss_driver/INSNavCart.msg, corresponding to SBF block ExtEventINSNavCart.
• /exteventinsnavgeod: publishes custom ROS message septentrio_gnss_driver/INSNavGeod.msg, corresponding to SBF block ExtEventINSNavGeod.
• /diagnostics: accepts generic ROS message diagnostic_msgs/DiagnosticArray.msg, converted from the SBF blocks QualityInd, ReceiverStatus and ReceiverSetup.
• /imu: accepts generic ROS message sensor_msgs/Imu.msg, converted from the SBF blocks ExtSensorMeas and INSNavGeod.
  • The ROS message sensor_msgs/Imu.msg can be fed directly into the robot_localization of the ROS navigation stack. Note that use_ros_axis_orientation should be set to true to adhere to the ENU convention.
• /localization: accepts generic ROS message nav_msgs/Odometry.msg, converted from the SBF block INSNavGeod and transformed to UTM.
  • The ROS message nav_msgs/Odometry.msg can be fed directly into the robot_localization of the ROS navigation stack. Note that use_ros_axis_orientation should be set to true to adhere to the ENU convention.

Suggestions for Improvements

Adding New SBF Blocks or NMEA Sentences