  The Ultra-relativistic Quantum Molecular Dynamics (UrQMD) transport approach
is used to calculate $\Delta$(1232) yields in Ca+Ca, Ni+Ni and Au+Au collisions
between 1 AGeV and 2 AGeV. We compare and validate two different methods to
extract the yields of $\Delta$(1232) resonances in such low energy nuclear
collisions: Firstly, the $\pi^-$ spectra at low $p_\mathrm{T}$ are used to
infer the $\Delta$(1232) yield in A+A collisions, a method employed by the
GSI/FOPI experiment. Secondly, we employ the invariant mass method used by the
HADES collaboration, which has recently reported data in the
$\Delta^{++}\rightarrow\pi^++p$ channel. We show that both methods are
compatible with each other and with the theoretical calculations, indicating
that the new HADES results are compatible with the previous FOPI measurements.
Then we use the $\Delta/nucleon$ ratio to extract the kinetic decoupling
temperatures of the $\Delta$(1232) resonances. We find that the extracted
temperatures are consistent with the predicted mass shift of the $\Delta$
resonance and the freeze-out parameters estimated from complementary studies
(blast wave fits, coarse graining).
