Sparse sensor array
Sparse sensor array, or simply sparse array, typically refers to a subset (thinned array) of a uniform linear or rectangular sensor array to achieve a high resolution of sensing capability, such as direction-of-arrival (DOA) estimation and computational imaging, as the uniform array but with a smaller number of elements. It may also achieve a higher number of degrees of freedom (DOFs), i.e., resolving more signals than the uniform array counterparts. Such advantages made sparse arrays attractive to achieve cost-effective array processing.
Traditional Sparse Designs
Sparse array design can be traced back to the 1950s as a means to achieve maximum resolution through long consecutive correlation lags [1][2]. The correlation lags form a set of difference coarrays.
Consider an -element uniform linear array (ULA) with a half-wavelength () inter-element spacing, which has an aperture of (also referred to have unit spacings) and the number of DOFs is , the minimum redundancy array (MRA) described in [2] can achieve an aperture in the order of . More precisely, the redundancy defined as , where is the greatest multiple of the unit spacing, is found to be between 1.217 and 1.674.
Several variations of sparse arrays exist. For example, the minimum hole array (MHA), also referred to as the Golomb array, minimizes the number of holes in the difference coarray while achieving the maximum number of lags in the resulting difference coarray [3][4].
Both MRA and MHA do not have a closed-form expression to allow systematic design. Their available solutions for the MRA for a large number of sensors are presented in [5][6].
Systematical Sparse Array Design
Efforts have been paid for the systematic design of sparse arrays which enable fast design, analysis of the properties of difference coarrays, and effective optimization. Passive and active ultrasonic sensing problems were considered for certain combinations of array configurations [7], and both one-dimensional (1-D) and two-dimensional (2-D) arrays were discussed. Later, the nested array[8] and coprime array
References
- ↑ Arsac, Jacques (January 1955). "Nouveau réseau pour l'observation radio astronomique de la brillance sur le soleil à 9359 Mc/s". Comptes Rendus De L'Academie Des Sciences. 240 (1): 942–945 – via Bibliothèque nationale de France.
- ↑ 2.0 2.1 Moffet, Alan T. (March 1968). "Minimum-Redundancy Linear Array". IEEE Transactions on Antennas and Propagation. AP-16 (2): 172–175 – via IEEE.
- ↑ Bloom, Gary S.; Golomb, Solomon W. (April 1977). "Applications of Numbered Undirected Graphs". Proceedings of IEEE. 65 (4): 562–570 – via IEEE.
- ↑ Vertatschitsch, E.; Haykin, S. (January 1986). "Nonredundant Arrays". Proceedings of the IEEE. 74 (1): 217 – via IEEE.
- ↑ Ishiguro, M. (November 1980). "Minimum redundancy linear arrays for a large number of antennas". Radio Science. 15 (6): 1163–1170 – via IEEE.
- ↑ Camps, Adriano; Cardama, Angel; Infantes, D. (December 2002). "Synthesis of Large Low-Redundancy Linear Arrays". IEEE Transactions on Antennas and Propagation. 49 (12): 1881–1883 – via IEEE.
- ↑ Hoctor, Ralph T.; Kassam, Saleem A. (April 1990). "The unifying role of the coarray in aperture synthesis for coherent and incoherent imaging". Proceedings of the IEEE. 78 (4): 735–752 – via IEEE.
- ↑ Pal, Piya; Vaidyanathan, P. P. (August 2010). "Nested Arrays: A Novel Approach to Array Processing With Enhanced Degrees of Freedom". IEEE Transactions on Signal Processing. 58 (8): 4167–4181 – via IEEE.
This article "Sparse sensor array" is from Wikipedia. The list of its authors can be seen in its historical and/or the page Edithistory:Sparse sensor array. Articles copied from Draft Namespace on Wikipedia could be seen on the Draft Namespace of Wikipedia and not main one.
