US 8,428,916 B2 · Modeling of the radiation belt megnetosphere in decisional timeframes

Abstract

Systems and methods for calculating L* in the magnetosphere with essentially the same accuracy as with a physics based model at many times the speed by developing a surrogate trained to be a surrogate for the physics-based model. The trained model can then beneficially process input data falling within the training range of the surrogate model. The surrogate model can be a feedforward neural network and the physics-based model can be the TSK03 model. Operatively, the surrogate model can use parameters on which the physics-based model was based, and/or spatial data for the location where L* is to be calculated. Surrogate models should be provided for each of a plurality of pitch angles. Accordingly, a surrogate model having a closed drift shell can be used from the plurality of models. The feedforward neural network can have a plurality of input-layer units, there being at least one input-layer unit for each physics-based model parameter, a plurality of hidden layer units and at least one output unit for the value of L*.

Claims13

Dependent claims

A computerized method of accelerating calculation of L* in accordance with physics-based model of conditions in a magnetosphere comprising:

defining a surrogate model to be a surrogate for a physics-based model of L* for magnetic belts based on formula L*=(2πμ0)/(ΦRE)
providing surrogate model computer instructions and surrogate model data;
training the surrogate model to be a surrogate for the physics-based model of L* for magnetic belts based on the formula L*=(2πμ0)/(ΦRE), wherein the physics-based model uses a plurality of physics-based model parameters, further comprising:
providing physics data based on the physics-based model parameters;
providing spatial data representing spatial coordinates for the location where L* is to be calculated;
providing surrogate models including sets of data for the physics-based model for each of a plurality of pitch angles;
selecting from the plurality of surrogate models at least one surrogate model set of data and instructions that calculate a closed drift shell for the physics-based model parameters and the spatial coordinates;
and
calculating L* by providing the physics-based model parameters and the spatial coordinates to the selected surrogate models that calculate a closed drift shell;
and
processing the trained surrogate model with a computer processor to accelerate the calculation of L* over a physics-based model.

8 more elements

A computerized method of accelerating calculation of L* in accordance with physics-based model of conditions in a magnetosphere comprising:

defining a surrogate model to be a surrogate for a physics-based model of L* for magnetic belts based on formula L*=(2πμ0)/(ΦRE);
providing surrogate model computer instructions and surrogate model data;
training the surrogate model to be a surrogate for the physics-based model of L* for magnetic belts based on the formula L*=(2πμ0)/(ΦRE);
processing the trained surrogate model with a computer processor to accelerate the calculation of L* over a physics-based model;
and
predicting an environment in the magnetosphere for a location at a second time later than a first time comprising:
calculating L* for the location at the first time using the surrogate model;
providing charge flux information for the location at the first time;
calculating the phase space density at the location at the first time from the value of L* at the location at the first time and the charge flux information for the location at the first time;
providing a radiation belt model;
forecasting the phase space density at the location at the second time using the radiation belt model and data assimilation methods;
calculating L* for the location at the second time using the surrogate model;
and
convert the phase space density at the location at the second time into a value of charge flux using the value of L* for the location at the second time,
wherein the calculated phase space density at the second time is compared to a predetermined value of phase space density to decide about operating a satellite's protections against space weather.

12 more elements

Dependencies are inferred from the claim text.

Modeling of the radiation belt megnetosphere in decisional timeframes

Life of this patent

Modeling of the radiation belt megnetosphere in decisional timeframes

Life of this patent

Abstract

Claims13