Ensemble

RocketPy allows you to use ensemble forecasts and reanalysis to simulate the atmospheric conditions for your rocket launch. Ensemble forecasts are a set of forecasts generated by running a model multiple times with slightly different initial conditions. This allows you to account for the uncertainty in the forecast and obtain a range of possible outcomes.

Tip

Ensemble models are extremely useful when running Monte Carlo simulations with RocketPy, as it allows you to add a level of uncertainty to your Environment model. One member forecast of the ensemble can be selected to run each flight simulation.

Ensemble Forecast

Global Ensemble Forecast System (GEFS)

Danger

GEFS shortcut unavailable: file="GEFS" is currently disabled in RocketPy because NOMADS OPeNDAP is deactivated for this endpoint.

Note

If you have a GEFS-compatible NetCDF or OPeNDAP dataset from another provider (or a local copy), you can still load it explicitly by passing the dataset path/URL in file and a compatible mapping in dictionary.

The GEFS model is a global ensemble forecast system useful for uncertainty analysis, but RocketPy’s automatic file="GEFS" shortcut is temporarily disabled.

from datetime import date, timedelta
from rocketpy import Environment

tomorrow = date.today() + timedelta(days=1)

env_gefs = Environment(
    date=(tomorrow.year, tomorrow.month, tomorrow.day, 18),
    latitude=-21.960641,
    longitude=-47.482122,
    elevation=640,
)
env_gefs.set_atmospheric_model(type="Ensemble", file="GEFS")

env_gefs.select_ensemble_member(3) # selects the 3rd forecast member

A very useful thing is to compare the forecast of all ensemble members, as well as confirming how many are there. All of this can be done by calling the rocketpy.Environment.all_info() method.

env_gefs.all_info()

CMC Ensemble

Danger

CMC Ensemble Model Unavailable: The CMC Ensemble model is temporarily deactivated in RocketPy due to recent updates on NOAA’s website, which resulted in a change of the model’s endpoint. Efforts are underway to restore access to the CMC Ensemble model as swiftly as possible.

At the moment, there is no built-in file="CMC" shortcut in Environment.set_atmospheric_model.

If you have a CMC-compatible NetCDF or OPeNDAP dataset, load it explicitly by passing the dataset path/URL in file and a matching mapping dictionary in dictionary.

Ensemble Reanalysis

Ensemble reanalyses are also possible with RocketPy. See the Ensemble section for more information.