Float Balloon Predictions - Possible Tawhiri Option

[darksidelemm]

Habhub has the ability to predict the flight path of a floating balloon flight using the 'Hysplit' trajectory model. This is commonly used to predict the expected future path of long duration floating balloon flights. Habhub uses the Hysplit trajectory model in 'ensemble' mode. This is where multiple predictions are run, with the starting altitude varied slightly. The model is run for 84 hours into the future.

I think we can do something similar using Tawhiri's 'float' prediction system. I suggest:

• If the altitude of the balloon is > 1km AGL, and the ascent rate is < 1m/s, add a 'float' button to the balloons pane, kind of like how the hysplit button appears on Habhub:

  

• If this is clicked, do the following:

  • Get the current position and altitude of the balloon.
  • Calculate the time 84 hours into the future from the time of the balloon.
  • Run the Tawhiri model using the float profile: https://tawhiri.readthedocs.io/en/latest/api.html#id2
  • Use parameters:
  • Start altitude: current_altitude - 20
  • ascent rate: 1m/s
  • stop_datetime: current time + 84 hours
  • float_altitude: multiple - use 2m steps between current_altitude-20 and current_altitude+20

Ideally each calculated trajectory should be plotted with a different color on the map.

[darksidelemm]

The name for this should be 'Float' not 'Hysplit', as we are not using Hysplit.