I have the given input for a system
$\begin{bmatrix}\dot{a}\\\dot{b} \\\dot{c} \end{bmatrix} = \begin{bmatrix} 0 & 1 & 0 \\ 0 & 0 & 1 \\ -18 & -27 & -10 \end{bmatrix} \begin{bmatrix} a \\ b \\ c \end{bmatrix} + \begin{bmatrix} 0 \\ 0 \\ 1 \end{bmatrix}d$
where the sensor measures c. In order to test for observability, I need the output matrices of the system (system is observable if observability matrix $\begin{bmatrix}C \\ CA \\ CA^2 \end{bmatrix}$ is full rank. Is there anyway to do this from the given problem, or is there another method of determining observability without the C matrix?