About page
the user can make a page in markdown format. The content will be shown in the About tab of the webserver:
AIS-catcher -N 8100 ABOUT about.md
Prometheus/Grafana interface
First functionality to output some metrics from AIS-catcher to Prometheus, see here.
JSON UDP input/output
JSON over UDP output: functionality to send NMEA messages packaged in a JSON object, e.g.:
AIS-catcher -u 192.168.1.235 4002 JSON on
JSON over UDP input: AIS-catcher accepts and parses this input when running as a UDP server, e.g.:
AIS-catcher -x 192.168.1.235 4002
Most external programs will not be able to accept this JSON packaged NMEA strings. It is a way to transfer received messages between AIS-catcher instances without losing meta data like the timestamp, ppm correction and signal level. These are not captured in the standard NMEA strings.
Writing AIS to PostgreSQL
The setup is fairly flexible and can be tailored to the particular needs. See READMEfor more details.
GPS, multiple receivers and plot station location on map
The latest version can run with multiple receivers in parallel. For example, one dongle for channel A+B and one dongle for channel C+D. To run with two receivers in parallel you can use a command like:
AIS-catcher -d serial1 -v -d serial2 -c CD -v -N 8100
There are a few other options that together can provide some interesting new functionality. Firstly, the webserver can share the location of the station with the front-end so it will be displayed on the map:
AIS-catcher -N 8100 share_loc on
This option is switched off by default for privacy reasons in case the webclient is shared externally. And secondly, the NMEA decoder accepts NMEA lines from a GPS device (NMEA lines GPRMC, GPGLL and GPGGA):
echo '$GPGGA, 161229.487, 3723.2475, N, 12158.3416, W, 1, 07, 1.0, 9.0, M, , , , 0000*18' | ./AIS-catcher -r txt .
These GPS coordinates will be used to set the location of the station. In this way the station can be visualized and tracked while on the move. This is useful if you use AIS-catcher to read from a hardware AIS receiver that has a built-in GPS.
All these new functions combined enables a command line like this:
AIS-catcher -r txt /dev/serial/by-id/usb-u-blox_AG_-_www.u-blox.com_u-blox_7_-_GPS_GNSS_Receiver-if00 -x 192.168.1.235 4002 -N 8100 share_loc on
The first receiver (-r txt ...) reads from a GPS device that is connected and emits NMEA lines. The second receiver (-x) reads AIS NMEA lines at port 4002 coming from another instance of AIS-catcher. The station is now plotted on the map with the location as provided by the GPS coordinates. The web-page has the ability to fix the center of the map on the location of the receiving station.
This functionality is new so reporting of bugs is appreciated.