I’m noticing some strange behavior with the
DSSTpropagator.computeOscullatingState() method. Specifically when I give it mean elements with small eccentricities, the results seem inaccurate.
For example, a test input with
e = 0.0
i = 0.0
Radius = 7393 km
returns an oscullating state with:
e = 0.00122
i = 0.0
Radius= 7384 km
(all after converting to/from equinoctial elements of course)
This unexpected shift in eccentricity and SMA occurs in a fairly large range of input eccentricity, but eventually goes away around e > 0.01. This also seems to be a function of input inclination as well, with mid-range inclination inputs of 60 deg showing the least shift.
Is this some known issue with the DSST conversion from mean to oscullating, or this orbit regime?
The force models I’m adding to the DSST propagator are:
Newtonian , Zonal, Tesseral gravity components of earth (that’s all), and experimented with using different rank/orders from 6 to 50 in the
I can try to set up a toy script to demonstrate this if this isn’t enough information.