How to get RCS of single particle?

[limilyli]

It's shown that the RCS calculation of particles is based on the Muller Matrix, so the result of calculation should be RCS with unit of 'm^2/m^3', i.e., the RCS in a unit volume. So I'm wondering how to get the single particle's RCS with unit of 'm^2'.

I'm looking forward to your reply. Thank you for your kindness!