Project Horus - Browser-Based HAB Chase Map

Note: This is a work-in-progress. Features may be incomplete or non-functional!

This folder contains code to display payload (and chase car!) position data in a web browser:

The general idea is this application is run on something like a Raspberry Pi (could be the same one that's running radiosonde_auto_rx?) and is accessed from a tablet or laptop computer via a web browser.

You also need flask, and flask-socketio, which can be installed using pip:

$ sudo pip install flask flask-socketio

You can then clone this repository with:

$ git clone https://github.com/projecthorus/chasemapper.git

Telemetry Sources

To use the map, you need some kind of data to plot on it! The mapping backend accepts telemetry data in a few formats:

• 'Payload Summary' and 'Chase Car Position' messages, via UDP broadcast in a JSON format described here. These can be generated by:
  • radiosonde_auto_rx - See here for configuration info.
  • Various 'bridge' utilities within the horus_utils repository. For example, FldigiBridge or HabitatBridge
• 'OziMux' messages, via UDP broadcast in a simple CSV format described here.
  • radiosonde_auto_rx - See here for configuration info.
  • Pi-in-the-Sky's lora_gateway - Using the OziPort=8942 configuration option.

Configuration & Startup

Many settings are defined in the horusmapper.cfg configuration file. Create a copy of the example config file using

$ cp horusmapper.cfg.example horusmapper.cfg

Edit this file with your preferred text editor. The configuration file is fairly descriptive - you will need to set:

• At least one telemetry 'profile', which defines where payload and (optionally) car position telemetry data is sourced from.
• A default latitude and longitude for the map to centre on.

You can then start-up the horusmapper server with:

$ python horusmapper.py

The server can be stopped with CTRL+C. Sometimes the server doesn't stop cleanly and may the process may need to be killed. (Sorry!)

You should then be able to access the webpage by visiting http://your_ip_here:5001/

Live Predictions

We can also run live predictions of the flight path.

To do this you need cusf_predictor_wrapper and it's dependencies installed. Refer to the documentation on how to install this.

Once compiled and installed, you will need to:

• Copy the 'pred' binary into this directory. If using the Windows build, this will be pred.exe; under Linux/OSX, just pred.
• Copy the 'get_wind_data.py' script from cusf_predictor_wrapper/apps into this directory.

You will then need to modify the horusmapper.cfg Predictor section setting as necessary to reflect the predictory binary location, the appropriate model_download command, and set [predictor] predictor_enabled = True

You can then click 'Download Model' in the web interface's setting tab to trigger a download of the latest GFS model data. Predictions will start automatically once a valid model is available.

Chase Car Positions

At the moment Chasemapper only supports receiving chase-car positions via Horus UDP messages. These can be generated by the ChaseTracker application from horus_utils. This application can also plot your position onto the tracker.habhub.org map, so others can see when you're out balloon chasing.

Eventually support will be added to get car positions from either GPSD, or from the client's device.

Offline Mapping via FoxtrotGPS's Tile Cache

(This is a work in progress) Chasemapper can serve up map tiles from a specified directory to the web client. Of course, for this to be useful, we need map tiles to server! FoxtrotGPS can help us with this, as it caches map tiles to ~/Maps/, with one subdirectory per map layer (i.e. ~/Maps/OSM/, ~/Maps/opencyclemap/).

This can be enabled by setting [offline_maps] tile_server_enabled = True, and changing [offline_maps] tile_server_path to point to your tile cache directory (i.e. /home/pi/Maps/). Chasemapper will assume each subdirectory in this folder is a valid map layer and will add them to the map layer list at the top-right of the interface.

Caching Maps

To grab map tiles to use with this, we're going to use FoxtrotGPS's Cached Maps feature.

• Install FoxtrotGPS (Linux only unfortunately, works OK on a Pi!) either from source, or via your system package manager (sudo apt-get install foxtrotgps).
• Load up FoxtrotGPS, and pan around the area you are intersted in caching. Pick the map layer you want, right-click on the map, and choose 'Map download'. You can then select how many zoom levels you want to cache, and start it downloading (this may take a while!)
• Once you have a set of folders within your ~/Maps cache directory, you can startup Chasemapper and start using them! Tiles will be served up as they become available.

(If anyone has managed to get ECW support working in GDAL recently, please contact me! I would like to convert some topographic maps in ECW format to tiles for use with Chasemapper.)

Running as a Systemd Service

Chasemapper can be operated in a 'continuous' mode, running as a systemd service. I use this in my chase car so that I can power up my car Raspberry Pi, and have services like auto_rx and chasemapper running immediately.

To set this up, the chasemapper.service file must be edited to include your username, and the path to this directory.

$ sudo cp chasemapper.service /etc/systemd/system/
$ sudo nano /etc/systemd/system/chasemapper.service

If you are not running chasemapper on a Raspberry Pi as the 'pi' user, you will need to edit the chasemapper.service file and modify the ExecStart, WorkingDirectory and User fields. Otherwise, leave all settings at their defaults:

[Unit]
Description=chasemapper
After=syslog.target

[Service]
ExecStart=/usr/bin/python /home/pi/chasemapper/horusmapper.py
Restart=always
RestartSec=3
WorkingDirectory=/home/pi/chasemapper/
User=pi
SyslogIdentifier=chasemapper

[Install]
WantedBy=multi-user.target

Once/if edited, install and start the service using:

$ sudo systemctl enable chasemapper.service
$ sudo systemctl start chasemapper.service

The debug log output can be viewed buy running:

$ sudo journalctl -u chasemapper.service -f -n

To stop the service, simply run:

$ sudo systemctl stop chasemapper.service

Contacts

• Mark Jessop - vk5qi@rfhead.net

You can often find me in the #highaltitude IRC Channel on Freenode.