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This phenomenon is primarily attributed to the Earth\u2019s rotation and range ambiguity. The increase in clutter degrees of freedom (DOFs) and the significant widening of the clutter suppression notch are not conducive to moving target detection near main lobe clutter. This paper proposes an effective approach to suppress non-stationary clutter based on an interpulse multi-frequency mode for SBEWR. Using the orthogonality of the uniform stepping frequency signal, partial range ambiguity can be effectively suppressed, and the clutter DOFs will be reduced. Subsequently, joint pitch-azimuth-Doppler three-dimensional spacetime adaptive processing and slant range preprocessing are used to perform clutter suppression. This combination not only curtails the estimation error associated with the clutter covariance matrix but also enhances the overall detection capabilities of the system. The simulation results verify the effectiveness of the proposed approach.<\/jats:p>","DOI":"10.3390\/rs16020314","type":"journal-article","created":{"date-parts":[[2024,1,12]],"date-time":"2024-01-12T07:47:16Z","timestamp":1705045636000},"page":"314","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["A Novel Non-Stationary Clutter Suppression Approach for Space-Based Early Warning Radar Using an Interpulse Multi-Frequency Mode"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3701-6183","authenticated-orcid":false,"given":"Ning","family":"Qiao","sequence":"first","affiliation":[{"name":"The School of Electronics and Information, Northwestern Polytechnical University, Xi\u2019an 710071, China"}]},{"given":"Shuangxi","family":"Zhang","sequence":"additional","affiliation":[{"name":"The School of Electronics and Information, Northwestern Polytechnical University, Xi\u2019an 710071, China"}]},{"given":"Shuo","family":"Zhang","sequence":"additional","affiliation":[{"name":"The School of Electronics and Information, Northwestern Polytechnical University, Xi\u2019an 710071, China"}]},{"given":"Qinglei","family":"Du","sequence":"additional","affiliation":[{"name":"The Department 3, Wuhan Radar Academy, Wuhan 430014, China"}]},{"given":"Yongliang","family":"Wang","sequence":"additional","affiliation":[{"name":"The School of Electronics and Information, Northwestern Polytechnical University, Xi\u2019an 710071, China"},{"name":"The Department 3, Wuhan Radar Academy, Wuhan 430014, China"}]}],"member":"1968","published-online":{"date-parts":[[2024,1,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"237","DOI":"10.1109\/TAES.1973.309792","article-title":"Theory of Adaptive Radar","volume":"9","author":"Brennan","year":"1973","journal-title":"IEEE Trans. Aerosp. Electron. Syst."},{"key":"ref_2","unstructured":"Pillai, S.U., Li, K.Y., and Himed, B. (2007). Space Based Radar, Theory & Applications, McGraw-Hill."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"70","DOI":"10.1109\/TAES.2003.1188894","article-title":"Robust space-time adaptive processing for airborne radar in nonhomogeneous clutter environments","volume":"39","author":"Wang","year":"2003","journal-title":"IEEE Trans. Aerosp. Electron. Syst."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"11217","DOI":"10.1109\/JSTARS.2021.3123648","article-title":"A Novel Clutter Covariance Matrix Estimation Method Based on Feature Subspace for Space-Based Early Warning Radar","volume":"14","author":"Zhang","year":"2021","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Han, J., Cao, Y., Wu, W., Wang, Y., Yeo, T.-S., Liu, S., and Wang, F. (2021). Robust GMTI Scheme for Highly Squinted Hypersonic Vehicle-Borne Multichannel SAR in Dive Mode. Remote Sens., 13.","DOI":"10.3390\/rs13214431"},{"key":"ref_6","unstructured":"Davis, M.E., Himed, B., and Zasada, D. (2003, January 5\u20138). Design of large space based radar for multimode surveillance. Proceedings of the 2003 IEEE Radar Conference, Huntsville, AL, USA."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"3050","DOI":"10.1109\/JSTARS.2014.2298242","article-title":"Modification of Multichannel Reconstruction Algorithm on the SAR With Linear Variation of PRI","volume":"7","author":"Luo","year":"2014","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_8","first-page":"1","article-title":"A Novel Dimension-Reduced Space\u2013Time Adaptive Processing Algorithm for Spaceborne Multichannel Surveillance Radar Systems Based on Spatial\u2013Temporal 2-D Sliding Window","volume":"60","author":"Huang","year":"2022","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"3236","DOI":"10.1109\/TAES.2022.3147136","article-title":"Multichannel Clutter Modeling, Analysis, and Suppression for Missile-Borne Radar Systems","volume":"58","author":"Huang","year":"2022","journal-title":"IEEE Trans. Aerosp. Electron. Syst."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"651","DOI":"10.1109\/TAES.2007.4285360","article-title":"Adaptive cancellation method for geometry-induced nonstationary bistatic clutter environments","volume":"43","author":"Melvin","year":"2007","journal-title":"IEEE Trans. Aerosp. Electron. Syst."},{"key":"ref_11","unstructured":"Lapierre, F., Neyt, X., and Verly, J.G. (2004). Evaluation of a Registration-Based Range-Dependence Compensation Method for a Bistatic STAP Radar Using Simulated, Random Snapshots. Proc. RADAR, 4."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Ries, P., Lesturgie, M., Lapierre, F.D., and Verly, J.G. (2007, January 10\u201312). Knowledge-aided array calibration for registration-based range-dependence compensation in airborne STAP radar with Conformal Antenna Arrays. Proceedings of the 2007 European Radar Conference, Munich, Germany.","DOI":"10.1109\/EURAD.2007.4404938"},{"key":"ref_13","unstructured":"Borsari, G.K. (1998, January 11\u201314). Mitigating effects on STAP processing caused by an inclined array. Proceedings of the 1998 IEEE Radar Conference, RADARCON\u201998. Challenges in Radar Systems and Solutions, Dallas, TX, USA."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1049\/iet-rsn:20070162","article-title":"Foundation for mitigating range dependence in radar space-time adaptive processing","volume":"3","author":"Lapierre","year":"2009","journal-title":"IET Radar Sonar Navig."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Wang, W., Wan, P., Zhang, J., Liu, Z., and Xu, J. (2021). Enhanced Pre-STAP Beamforming for Range Ambiguous Clutter Separation with Vertical FDA Radar. Remote Sens., 13.","DOI":"10.3390\/rs13245145"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"917","DOI":"10.1109\/TAES.2006.248188","article-title":"Effect of earth\u2019s rotation and range foldover on space-based radar performance","volume":"42","author":"Pillai","year":"2006","journal-title":"IEEE Trans. Aerosp. Electron. Syst."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1109\/MAES.2004.1263229","article-title":"A STAP overview","volume":"19","author":"Melvin","year":"2004","journal-title":"IEEE Trans. Aerosp. Electron. Syst."},{"key":"ref_18","unstructured":"Guerci, J. (2014). Space-Time Adaptive Processing for Radar, Artech House. [2nd ed.]."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Davis, M.E. (2002, January 15\u201317). Space based radar moving target detection challenges. Proceedings of the RADAR 2002, Edinburgh, UK.","DOI":"10.1049\/cp:20020265"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Wicks, M.C. (2009, January 4\u20138). A brief history of waveform diversity. Proceedings of the 2009 IEEE Radar Conference, Pasadena, CA, USA.","DOI":"10.1109\/RADAR.2009.4977142"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"6954","DOI":"10.1109\/TAES.2023.3281305","article-title":"Range-Ambiguous Sea Clutter Suppression for Multichannel Spaceborne Radar Applications Via Alternating APC Processing","volume":"59","author":"Huang","year":"2023","journal-title":"IEEE Trans. Aerosp. Electron. Syst."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"5040","DOI":"10.1109\/JSTARS.2015.2485166","article-title":"Multichannel SAR Using Waveform Diversity and Distinct Carrier Frequency for Ground Moving Target Indication","volume":"8","author":"Wang","year":"2015","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"8473","DOI":"10.1109\/JSTARS.2022.3210907","article-title":"Method of Range Ambiguity Suppression Combining Sparse Reconstruction and Matched Filter","volume":"15","author":"Qi","year":"2022","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Wang, Z., Chen, W., Zhang, T., Xing, M., and Wang, Y. (2022). Improved Dimension-Reduced Structures of 3D-STAP on Nonstationary Clutter Suppression for Space-Based Early Warning Radar. Remote Sens., 14.","DOI":"10.3390\/rs14164011"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"77","DOI":"10.1049\/ip-rsn:20020077","article-title":"Performance characterisation of hybrid STAP architecture incorporating elevation interferometry","volume":"149","author":"Hale","year":"2002","journal-title":"IEE Proc. Radar Sonar Navig."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Hale, T.B., Temple, M.A., Raquet, J.F., Oxley, M.E., and Wicks, M.C. (2002, January 15\u201317). Localized three-dimensional adaptive spatial-temporal processing for airborne radar. Proceedings of the RADAR 2002, Edinburgh, UK.","DOI":"10.1049\/cp:20020275"},{"key":"ref_27","unstructured":"Corbell, P.M., and Hale, T.B. (2004, January 26\u201329). 3-dimensional STAP performance analysis using the cross-spectral metric. Proceedings of the 2004 IEEE Radar Conference, Philadelphia, PA, USA."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"556","DOI":"10.1049\/rsn2.12360","article-title":"A severely range ambiguous clutter suppression method based on multi-domain cascaded signal processing for space-based early warning radar","volume":"17","author":"Zhang","year":"2023","journal-title":"IET Radar Sonar Navig."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"2032","DOI":"10.1109\/TVT.2021.3057436","article-title":"Range Ambiguous Clutter Suppression for FDA-MIMO Forward Looking Airborne Radar Based on Main Lobe Correction","volume":"70","author":"Wang","year":"2021","journal-title":"IEEE Trans. Veh. Technol."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"5352","DOI":"10.1109\/TGRS.2016.2561308","article-title":"Space-Time Adaptive Processing With Vertical Frequency Diverse Array for Range-Ambiguous Clutter Suppression","volume":"54","author":"Xu","year":"2016","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"309","DOI":"10.1109\/JSTSP.2016.2615269","article-title":"An Adaptive Range-Angle-Doppler Processing Approach for FDA-MIMO Radar Using Three-Dimensional Localization","volume":"11","author":"Xu","year":"2017","journal-title":"IEEE J. Sel. Top. Signal Process."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"107323","DOI":"10.1016\/j.sigpro.2019.107323","article-title":"A novel range ambiguity resolving approach for high-resolution and wide-swath SAR imaging utilizing space-pulse phase coding","volume":"68","author":"Wang","year":"2020","journal-title":"Signal Process."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Zhang, T., Wang, Z., Xing, M., Zhang, S., and Wang, Y. (2022). Research on Multi-Domain Dimensionality Reduction Joint Adaptive Processing Method for Range Ambiguous Clutter of FDA-Phase-MIMO Space-Based Early Warning Radar. Remote Sens., 14.","DOI":"10.3390\/rs14215536"},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Roemer, C. (2017, January 23\u201328). Introduction to a new wide area sar mode using the F-SCAN principle. Proceedings of the 2017 IEEE International Geoscience and Remote Sensing Symposium (IGARSS), Fort Worth, TX, USA.","DOI":"10.1109\/IGARSS.2017.8127840"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"6434","DOI":"10.1109\/TGRS.2020.2976864","article-title":"Signal Modeling and Analysis for Elevation Frequency Scanning HRWS SAR","volume":"58","author":"Liu","year":"2020","journal-title":"IEEE Trans. Geos. Remote Sens."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1046","DOI":"10.1049\/iet-rsn.2015.0311","article-title":"Simple transmit diversity technique for phased array radar","volume":"10","author":"Babur","year":"2016","journal-title":"IET Radar Sonar Navig."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"610","DOI":"10.1049\/iet-rsn.2017.0386","article-title":"Transmit beampattern synthesis for MIMO radar using extended circulating code","volume":"12","author":"Li","year":"2018","journal-title":"IET Radar Sonar Navig."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"855","DOI":"10.1109\/TAES.2021.3104528","article-title":"Range-Dependent Ambiguous Clutter Suppression for Airborne SSF-STAP Radar","volume":"58","author":"Chen","year":"2022","journal-title":"IEEE Trans. Aerosp. Electron. 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