ianfixes / nmea_plus_google_earth

Converts incoming NMEA/AIS data to a live Google Earth overlay of ship positions

Google Earth viewer for NMEA and AIS Data

Converts incoming NMEA/AIS data to a live Google Earth overlay of ship positions, demonstrating the capabilities of the nmea_plus gem: https://github.com/ianfixes/nmea_plus

Here are some example screenshots from a live view of Boston harbor. See also, this video https://www.youtube.com/watch?v=yvkCEd93p_E

Cruise ship at the dock

Tugs at the dock

For boats that spend a lot of time at their moorings, the Google Earth imagery and the live data sometimes align.

Tugs guiding a container ship

Note that this image is from an earlier buggy version where one side of the ship polygon was not drawn -- I didn't connect the last point back to the initial one.

Tugs guiding a bulk carrier

Note the white lines drawn under the ships. Since the position updates do not happen every second, it's helpful to use their reported speed and bearing to estimate their position -- rather than falsely believe they have stayed put for ten seconds.

Installation

This is not a published Gem, due to custom features in some dependent gems that (as of this writing) have not been accepted and/or published upstream.

$ git clone [email protected]:ianfixes/nmea_plus_google_earth.git
$ cd nmea_plus_google_earth
$ bundle install

Operation

Demo program

To watch a brief demo with canned data (recorded in Boston harbor), run

$ bundle exec ruby exe/canned_data_demo.rb

and add http://localhost:7447 as a network link in Google Earth. You may need to configure the link to refresh at some regular interval (I use 4 seconds to avoid flickering).

Write your own program

All that is necessary is a Ruby IO object source for the input data (which can be a file, string, serial port, network connection, etc) -- technically anything that provides each_line. For example, here is a process that will read data from the serial port and publish on port 12345.

require 'nmea_plus_google_earth'
require 'serialport'

server = NMEAPlusGoogleEarth::GoogleEarthVisualizer.new(12345)
server.process(SerialPort.new("/dev/tty.usbserial", 38400, 8, 1, SerialPort::NONE))