{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,17]],"date-time":"2026-02-17T12:15:42Z","timestamp":1771330542258,"version":"3.50.1"},"reference-count":49,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2023,3,15]],"date-time":"2023-03-15T00:00:00Z","timestamp":1678838400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Height estimation of scatterers in complex environments via the Tomographic Synthetic Aperture Radar (TomoSAR) technique is still a valuable research field. The parametric spectral estimation approach constitutes a powerful tool to identify the superimposed scatterers with different complex reflectivities, located at different heights in the same range\u2013azimuth resolution cell. Unfortunately, this approach requires prior knowledge about the number of scatterers for each pixel, which is not possible in practical situations. In this paper, we propose a method that analyzes the scree plot, generated from the spectral decomposition of the multidimensional covariance matrix, in order to estimate automatically the number of scatterers for each resolution cell. In this context, a properly improved regularization step is included during the reconstruction process, transforming the parametric MUSIC estimator into a non-parametric method. The experimental results on two data sets covering high elevation towers, with different facade coating characteristics, acquired by the TerraSAR-X satellite highlighted the effectiveness of the proposed regularized MUSIC for the reconstruction of high man-made structures compared with classical approaches.<\/jats:p>","DOI":"10.3390\/rs15061599","type":"journal-article","created":{"date-parts":[[2023,3,15]],"date-time":"2023-03-15T06:53:32Z","timestamp":1678863212000},"page":"1599","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Non-Parametric Tomographic SAR Reconstruction via Improved Regularized MUSIC"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9778-0944","authenticated-orcid":false,"given":"Karima","family":"Hadj-Rabah","sequence":"first","affiliation":[{"name":"D\u00e9partement de T\u00e9l\u00e9communication, Universit\u00e9 des Sciences et de la Technologie Houari Boumedi\u00e8ne, BP 32, Bab Ezzouar 16111, Algeria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9656-2969","authenticated-orcid":false,"given":"Gilda","family":"Schirinzi","sequence":"additional","affiliation":[{"name":"Dipartimento di Ingegneria, Universit\u00e0 di Napoli \u201cParthenope\u201d, 80143 Napoli, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6551-7834","authenticated-orcid":false,"given":"Alessandra","family":"Budillon","sequence":"additional","affiliation":[{"name":"Dipartimento di Ingegneria, Universit\u00e0 di Napoli \u201cParthenope\u201d, 80143 Napoli, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Faiza","family":"Hocine","sequence":"additional","affiliation":[{"name":"D\u00e9partement de T\u00e9l\u00e9communication, Universit\u00e9 des Sciences et de la Technologie Houari Boumedi\u00e8ne, BP 32, Bab Ezzouar 16111, Algeria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Aichouche","family":"Belhadj-Aissa","sequence":"additional","affiliation":[{"name":"D\u00e9partement de T\u00e9l\u00e9communication, Universit\u00e9 des Sciences et de la Technologie Houari Boumedi\u00e8ne, BP 32, Bab Ezzouar 16111, Algeria"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,3,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"154","DOI":"10.1109\/JOE.1980.1145451","article-title":"The Seasat-A synthetic aperture radar system","volume":"5","author":"Jordan","year":"1980","journal-title":"IEEE J. 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