Table 2.

Configurations which satisfy $H^{T}H=\frac{n}{3}I$ for n = 4.

	Configuration Diagram	Measurement Matrix
1		$H=\left[\begin{array}{ccc}\frac{2\sqrt{2}}{3}& 0& \frac{1}{3}\\ -\frac{\sqrt{2}}{3}& \frac{\sqrt{6}}{3}& \frac{1}{3}\\ -\frac{\sqrt{2}}{3}& -\frac{\sqrt{6}}{3}& \frac{1}{3}\\ 0& 0& 1\end{array}\right]$
2		$H=\frac{1}{\sqrt{3}}\left[\begin{array}{ccc}-1& -1& 1\\ 1& -1& 1\\ 1& 1& 1\\ -1& 1& 1\end{array}\right]$