{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,26]],"date-time":"2025-11-26T16:29:57Z","timestamp":1764174597754,"version":"build-2065373602"},"reference-count":30,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2018,11,27]],"date-time":"2018-11-27T00:00:00Z","timestamp":1543276800000},"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>Synthetic Aperture Radar (SAR) Tomography (TomoSAR) allows extending the 2-D focusing capabilities of SAR to the elevation direction, orthogonal to the azimuth and range. The multi-dimensional extension (along the time) also enables the monitoring of possible scatterer displacements. A key aspect of TomoSAR is the identification, in the presence of noise, of multiple persistent scatterers interfering within the same 2-D (azimuth range plane) pixel. To this aim, the use of multi-look has been shown to provide tangible improvements in the detection of single and double interfering persistent scatterers at the expense of a minor spatial resolution loss. Depending on the system acquisition characteristics, this operation may require also the detection of multiple scatterers interfering at distances lower than the Rayleigh resolution (super-resolution). In this work we further investigated the use of multi-look in TomoSAR for the detection of multiple scatterers located also below the Rayleigh resolution. A solution relying on the Capon filtering was first analyzed, due to its improved capabilities in the separation of the responses of multiple scatterers and sidelobe suppression. Moreover, in the framework of the Generalized Likelihood Ratio Test (GLRT), the single-look support based detection strategy recently proposed in the literature was extended to the multi-look case. Experimental results of tests carried out on two datasets acquired by TerraSAR-X and COSMO-SkyMED sensors are provided to show the performances of the proposed solution as well as the effects of the baseline span of the dataset for the detection capabilities of interfering scatterers.<\/jats:p>","DOI":"10.3390\/rs10121894","type":"journal-article","created":{"date-parts":[[2018,11,27]],"date-time":"2018-11-27T12:17:35Z","timestamp":1543321055000},"page":"1894","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":18,"title":["Super-Resolution Multi-Look Detection in SAR Tomography"],"prefix":"10.3390","volume":"10","author":[{"given":"Cosmin","family":"D\u0103ni\u0219or","sequence":"first","affiliation":[{"name":"Department of Applied Electronics and Information Engineering, University Politehnica of Bucharest,  060042 Bucharest, Romania"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gianfranco","family":"Fornaro","sequence":"additional","affiliation":[{"name":"Institute for Electromagnetic Sensing of the Environment, National Research Council of Italy, 00185 Rome, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8853-2818","authenticated-orcid":false,"given":"Antonio","family":"Pauciullo","sequence":"additional","affiliation":[{"name":"Institute for Electromagnetic Sensing of the Environment, National Research Council of Italy, 00185 Rome, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Diego","family":"Reale","sequence":"additional","affiliation":[{"name":"Institute for Electromagnetic Sensing of the Environment, National Research Council of Italy, 00185 Rome, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mihai","family":"Datcu","sequence":"additional","affiliation":[{"name":"Department of Applied Electronics and Information Engineering, University Politehnica of Bucharest,  060042 Bucharest, Romania"},{"name":"Remote Sensing Technology Institute, German Aerospace Center, D-82234 Wessling, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2018,11,27]]},"reference":[{"key":"ref_1","unstructured":"Fornaro, G., and Pauciullo, A. (2018). Interferometric and Tomographic SAR. Novel Radar Techniques and Applications, Scitech Publishing."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1109\/36.898661","article-title":"Permanent scatterers in SAR interferometry","volume":"39","author":"Ferretti","year":"2001","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"2142","DOI":"10.1109\/36.868873","article-title":"First demonstration of airborne SAR tomography using multibaseline L-band data","volume":"38","author":"Reigber","year":"2000","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"224","DOI":"10.1109\/TGRS.2008.2000837","article-title":"Four-Dimensional SAR Imaging for Height Estimation and Monitoring of Single and Double Scatterers","volume":"47","author":"Fornaro","year":"2009","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"41","DOI":"10.1109\/MSP.2014.2312073","article-title":"Tomographic Processing of Interferometric SAR Data: Developments, applications, and future research perspectives","volume":"31","author":"Fornaro","year":"2014","journal-title":"IEEE Signal Process. Mag."},{"key":"ref_6","unstructured":"Fornaro, G., Pauciullo, A., Reale, D., Zhu, X., and Bamler, R. (2012). SAR Tomography: An advanced tool for spaceborne 4D radar scanning with application to imaging and monitoring of cities and single buildings. IEEE Geosci. Remote Sens. Soc. Newslett., 9\u201317."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"488","DOI":"10.1109\/TGRS.2010.2054099","article-title":"Three-Dimensional SAR Focusing from Multipass Signals Using Compressive Sampling","volume":"49","author":"Budillon","year":"2011","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"4296","DOI":"10.1109\/TGRS.2010.2050487","article-title":"Very High Resolution Spaceborne SAR Tomography in Urban Environment","volume":"48","author":"Zhu","year":"2010","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1344","DOI":"10.1109\/TAES.2002.1145755","article-title":"Layover solution in multibaseline SAR interferometry","volume":"38","author":"Gini","year":"2002","journal-title":"IEEE Trans. Aerosp. Electron. Syst."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Biondi, F. (2014, January 13\u201318). SAR tomography optimization by interior point methods via atomic decomposition\u2014The convex optimization approach. Proceedings of the 2014 IEEE International Geoscience and Remote Sensing Symposium (IGARSS), Quebec City, QC, Canada.","DOI":"10.1109\/IGARSS.2014.6946823"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"557","DOI":"10.1049\/el.2015.3414","article-title":"Single-look light-burden superresolution differential SAR tomography","volume":"52","author":"Lombardini","year":"2016","journal-title":"Electron. Lett."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"2832","DOI":"10.1109\/TGRS.2015.2506399","article-title":"Single and Multipolarimetric P-Band SAR Tomography of Subsurface Ice Structure","volume":"54","author":"Banda","year":"2016","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"6","DOI":"10.1109\/MGRS.2013.2248301","article-title":"A Tutorial on Synthetic Aperture Radar","volume":"1","author":"Moreira","year":"2013","journal-title":"IEEE Geosci. Remote Sens. Mag."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2284","DOI":"10.1109\/TGRS.2008.2000837","article-title":"Detection of Single Scatterers in Multidimensional SAR Imaging","volume":"47","author":"Fornaro","year":"2009","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"3567","DOI":"10.1109\/TGRS.2012.2183002","article-title":"Detection of Double Scatterers in SAR Tomography","volume":"50","author":"Pauciullo","year":"2012","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1086","DOI":"10.1109\/JSTARS.2015.2494376","article-title":"GLRT Based on Support Estimation for Multiple Scatterers Detection in SAR Tomography","volume":"9","author":"Budillon","year":"2016","journal-title":"IEEE J. Sel. Top. Appl. Earth Observ. Remote Sens."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"2768","DOI":"10.1109\/JSTARS.2017.2657227","article-title":"A Fast Support Detector for Superresolution Localization of Multiple Scatterers in SAR Tomography","volume":"10","author":"Budillon","year":"2017","journal-title":"IEEE J. Sel. Top. Appl. Earth Observ. Remote Sens."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"2375","DOI":"10.1109\/TGRS.2002.803792","article-title":"A new algorithm for surface deformation monitoring based on small baseline differential SAR interferograms","volume":"40","author":"Berardino","year":"2002","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"3460","DOI":"10.1109\/TGRS.2011.2124465","article-title":"A New Algorithm for Processing Interferometric Data-Stacks: SqueeSAR","volume":"49","author":"Ferretti","year":"2011","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2050","DOI":"10.1109\/TGRS.2014.2352853","article-title":"CAESAR: An Approach Based on Covariance Matrix Decomposition to Improve Multibaseline\u2013Multitemporal Interferometric SAR Processing","volume":"53","author":"Fornaro","year":"2015","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"2776","DOI":"10.1109\/JSTARS.2014.2316323","article-title":"Multilook SAR Tomography for 3-D Reconstruction and Monitoring of Single Structures Applied to COSMO-SKYMED Data","volume":"7","author":"Fornaro","year":"2014","journal-title":"IEEE J. Sel. Top. Appl. Earth Observ. Remote Sens."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Pauciullo, A., Reale, D., Franze, W., and Fornaro, G. (2018). Multi-Look in GLRT-Based Detection of Single and Double Persistent Scatterers. IEEE Trans. Geosci. Remote Sens., 1\u201313.","DOI":"10.1109\/TGRS.2018.2809538"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1117","DOI":"10.1109\/TGRS.2011.2164925","article-title":"Superresolution Differential Tomography: Experiments on Identification of Multiple Scatterers in Spaceborne SAR Data","volume":"50","author":"Lombardini","year":"2012","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"507","DOI":"10.1109\/TGRS.2003.809934","article-title":"Three-dimensional focusing with multipass SAR data","volume":"41","author":"Fornaro","year":"2003","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"5296","DOI":"10.1109\/TGRS.2012.2233205","article-title":"Extension of 4-D SAR Imaging to the Monitoring of Thermally Dilating Scatterers","volume":"51","author":"Reale","year":"2013","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_26","unstructured":"Stoica, P., and Moses, R. (2005). Spectral Analysis of Signals, Pearson Prentice Hall."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"844","DOI":"10.3390\/rs9080844","article-title":"Extension of a Fast GLRT Algorithm to 5D SAR Tomography of Urban Areas","volume":"9","author":"Budillon","year":"2017","journal-title":"Remote Sens."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"115","DOI":"10.1111\/j.2517-6161.1970.tb00821.x","article-title":"Use of the Kolmogorov-Smirnov Cramer-Von Mises and related statistics without extensive tables","volume":"32","author":"Stephens","year":"1970","journal-title":"J. R. Stat. Soc. Ser. B"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"6119","DOI":"10.1109\/TGRS.2016.2581261","article-title":"Single-Look SAR Tomography as an Add-On to PSI for Improved Deformation Analysis in Urban Areas","volume":"54","author":"Siddique","year":"2016","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1109\/MSP.2014.2312098","article-title":"Superresolving SAR tomography for multidimensional imaging of urban areas: Compressive sensing-based TomoSAR inversion","volume":"31","author":"Zhu","year":"2014","journal-title":"IEEE Signal Process. Mag."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/10\/12\/1894\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T15:32:40Z","timestamp":1760196760000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/10\/12\/1894"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,11,27]]},"references-count":30,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2018,12]]}},"alternative-id":["rs10121894"],"URL":"https:\/\/doi.org\/10.3390\/rs10121894","relation":{},"ISSN":["2072-4292"],"issn-type":[{"type":"electronic","value":"2072-4292"}],"subject":[],"published":{"date-parts":[[2018,11,27]]}}}