I am reading through examples of linear filtering problems for SDE's, and the process first requires solving a (deterministic) riccati differential equation. In one of the examples, this is given by:
$$\frac{dS_t}{dt} = \frac{-1}{m^2}S^2_t + c^2$$
to solve it, they first rearrange it as
$$\frac{m^2 dS_t}{m^2 c^2 -S^2_t} = dt$$
and then state (without working or explanation) that this gives
$$\left| \frac{mc+S_t}{mc-S_t} \right|= \left| \frac{mc+a^2}{mc-a^2} \right| \exp \left( \frac{2ct}{m} \right)$$
And I'm unsure how to get from one to the other.
Clearly, since $t$ has emerged, it involves integrating both sides. But besides that I'm lost. Could someone explain this or give some steps/outline for me to do myself?
Don't see this as Riccati equation, see it as separable ODE with constant solutions at $\pm mc$. Then the last form has a partial fraction decomposition $$ \frac{mdS}{S+mc}-\frac{mdS}{S-mc} = 2cdt $$ which after integration and determination of the integration constant should give your solution form.