Array calibration using pilot sources
estpos = pilotcalib(nompos,x,pilotang)
[estpos,esttaper]
= pilotcalib(nompos,x,pilotang)
[estpos,esttaper]
= pilotcalib(nompos,x,pilotang,nomtaper)
[estpos,esttaper]
= pilotcalib(nompos,x,pilotang,nomtaper,uncerts)
returns
the estimated element positions, estpos
= pilotcalib(nompos
,x
,pilotang
)estpos
, of a
sensor array. The argument nompos
represents
the relative nominal positions of the sensor array before calibration.
The nominal position is relative to the first element of the array.
The argument x
represents the signals received
by the array coming from the pilot sources. The argument pilotang
contains
the known directions of each of the pilot sources. Three or more pilot
sources are required in this case.
[
also returns the estimated array taper, estpos
,esttaper
]
= pilotcalib(nompos
,x
,pilotang
)esttaper
.
Each element of esttaper
contains the estimated
taper value of the corresponding array element. In this case, the
prior nominal taper is one for each element. Four or more pilot sources
are required in this case.
This algorithm requires that the pilot sources be independent narrowband plane-wave signals incoming from the far field region of the array. In addition, signals must not exhibit multipath propagation effects or coherence. All elements in the sensor array are assumed to be isotropic.
The algorithm calibrates relative positions of the array sensors with respect to the first sensor. To use the algorithm, first subtract the position of the first element from each element, then pass the relative array into the function as the nominal position argument to produced the calibrated relative positions. Finally, add back the first element position to all the relative positions to create the fully calibrated array.
[1] N. Fistas and A. Manikas, "A New General Global Array Calibration Method", IEEE Proceedings of ICASSP, Vol. IV, pp. 73-76, April 1994.