I am building a satellite orbit propagator in MATLAB and I am using STK as a reference.
Comparing TwoBody propagator using RKN78 (MATLAB) with HPOP (degree 1, order 1), I am getting quite good results in the ICRF coordinate system, but when I transform the MATLAB results in the Inertial frame to the Earth fixed frame considering the precession, nutation and polar motion of Earth and compare the results with HPOP (degree 1, order 1) in the fixed frame, I get position error in few hundred meters for 1 orbit simulation period.
I am looking for more accurate result so is there a way to play with the ICRF-Fixed transformation in STK settings ?
AGI states the following in their online documentation for ICRF-Fixed transformation
"Earth realizes its Fixed frame from the transformation algorithm between it and the ICRF. The transformation includes precession, nutation, and rotation effects, as well as pole wander and frame corrections."