I am working on a simulation to propagate uncertainties of a spacecraft/ orbit due to imperfect knowledge of its initial state vector and disturbance force parameters. I am doing this in OREKIT 11.0
So far i have reproduced the FieldPropagation available in the GitLab tutorials but I changed it from a Keplerian orbit to a Cartesian orbit.
First of all, I would like to include the effect of uncertainties in the acceleration due to drag through the drag coefficient. My understanding, from a post of 2018 vintage from @luc is that I have to do the following:
- Define a custom acceleration method that “takes a FieldSpacecraftState and an array of Field elements that correspond to the current value of the force model parameters.”
- “Before propagation start you will have to set up the parameters for the force model…” as shown by @Luc in the reply.
I am stuck because I don’t know how to implement step 1 in general and in particular for the acceleration due to drag. The IsotropicDrag class has methods that calculate both regular acceleration and a field one. Should I start by rewriting it?
Thank you for your help.