$\mathsf{\Gamma }$	Reflection coefficient
${ϵ}_{\mathrm{loc}}$	Localization error
${\epsilon }_r$	Relative permittivity
$\mathsf{\Delta }$ [m]	Inter element distance
$\mathsf{\Delta }h$ [m]	Boundary imperfection
$\eta \left(t\right)$	Noise signal
$\theta$	Angle of arrival
$\lambda$	Wavelength
${\mu }_l$	Phase difference between array elements
${\mu }_r$	Relative permeability
${\mathsf{\Pi }}_M$	$M\times M$ exchange matrix
${\sigma }_{\eta }^2$	Noise variance
$\tau$	Time delay
${\varphi }_{\mathrm{i}}$	Angle of an incident wave
${\varphi }_{\mathrm{r}}$	Angle of a reflected wave
${\varphi }_{\mathrm{t}}$	Angle of a transmitted wave
$\mathit{a}\left(\theta \right)$	Array steering vector
$\mathit{A}$	Array manifold
B	Number of antenna arrays
c	Speed of light
d	Distance
$\mathit{E}$	Electric field vector
f	Frequency
$\mathit{f}$	Fingerprint vector
$\mathit{H}$	Magnetic field vector
$H(f,\theta )$	Antenna response
$h\left(\theta \right)$	Filter window
$K_{ss}$	Number of spatial smoothings
L [dB]	Loss
L	Number of signal sources
$\mathit{m}$	Measurement vector
M	Number of antennas in an array
n	Refractive index
N	Number of array snapshots
$\mathit{p}$	Position vector
$P\left(\theta \right)$	Spatial spectrum
$P_{\mathrm{i}}$	Power of an incident wave
$P_{\mathrm{r}}$	Power of a reflected wave
$P_{\mathrm{t}}$	Power of a transmitted wave
$P_{\mathrm{PDF}}\left(\theta \right)$	Angular probability density function
$\mathit{R}$	Spatial covariance matrix
${\mathit{R}}_{\eta }$	Spatial correlation matrix of $\mathit{\eta }\left(t\right)$
$r\left(t\right)$	Received signal
$r_{\mathrm{corr}}$	Pearson correlation coefficient
$r_{\mathrm{SPDF}}$	Spatial probability density function
$\mathit{S}$	Spatial correlation matrix of $\mathit{s}\left(t\right)$
$s\left(t\right)$	Transmitted signal
$SI$	Surface interval
$\mathcal{T}$	Training vector
$\mathit{w}$	Weight vector
W	Window width
Z	Impedance