{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T00:30:04Z","timestamp":1760229004498,"version":"build-2065373602"},"reference-count":46,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2022,5,29]],"date-time":"2022-05-29T00:00:00Z","timestamp":1653782400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"the National Natural Science Foundation of China","award":["42171355","42071410","41904002","42104023","2019ZDZX0042","2020YJ0322","2020JDTD0003","205200100564","205200100588","2020YBPY12"],"award-info":[{"award-number":["42171355","42071410","41904002","42104023","2019ZDZX0042","2020YJ0322","2020JDTD0003","205200100564","205200100588","2020YBPY12"]}]},{"name":"the Sichuan Science and Technology Program","award":["42171355","42071410","41904002","42104023","2019ZDZX0042","2020YJ0322","2020JDTD0003","205200100564","205200100588","2020YBPY12"],"award-info":[{"award-number":["42171355","42071410","41904002","42104023","2019ZDZX0042","2020YJ0322","2020JDTD0003","205200100564","205200100588","2020YBPY12"]}]},{"name":"the Jiangxi University of Science and Technology High-level Talent Research Startup Project","award":["42171355","42071410","41904002","42104023","2019ZDZX0042","2020YJ0322","2020JDTD0003","205200100564","205200100588","2020YBPY12"],"award-info":[{"award-number":["42171355","42071410","41904002","42104023","2019ZDZX0042","2020YJ0322","2020JDTD0003","205200100564","205200100588","2020YBPY12"]}]},{"name":"the Excellent Doctoral Dissertation of Southwest Jiaotong University","award":["42171355","42071410","41904002","42104023","2019ZDZX0042","2020YJ0322","2020JDTD0003","205200100564","205200100588","2020YBPY12"],"award-info":[{"award-number":["42171355","42071410","41904002","42104023","2019ZDZX0042","2020YJ0322","2020JDTD0003","205200100564","205200100588","2020YBPY12"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>The use of the conventional interferometric synthetic aperture radar (InSAR) to generate digital elevation models (DEMs) always encounters phase unwrapping (PU) errors in areas with a sizeable topographic gradient. Range split-spectrum interferometry (RSSI) can overcome this issue; however, it loses the spatial resolution of the SAR image. We propose the use of the RSSI-assisted In-SAR-derived DEM (RID) method to address this challenge. The proposed approach first applies the RSSI method to generate a prior DEM, used for simulating terrain phases. Then, the simulated terrain phases are subtracted from the wrapped InSAR phases to obtain wrapped residual phases. Finally, the residual phases are unwrapped by the minimum cost flow (MCF) method, and the unwrapped residual phases are added to the simulated phases. Both the simulated and TerraSAR-X data sets are used to verify the proposed method. Compared with the InSAR and RSSI methods, the proposed approach can effectively decrease the PU errors of large gradients, ensure data resolution, and guarantee the DEM\u2019s accuracy. The root mean square error between the topographic phase simulated from the real DEM and the topographic phase generated from the proposed method is 2.22 rad, which is significantly lower than 6.60 rad for InSAR, and the improvement rate is about 66.36%.<\/jats:p>","DOI":"10.3390\/rs14112607","type":"journal-article","created":{"date-parts":[[2022,5,31]],"date-time":"2022-05-31T02:30:06Z","timestamp":1653964206000},"page":"2607","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Using Range Split-Spectrum Interferometry to Reduce Phase Unwrapping Errors for InSAR-Derived DEM in Large Gradient Region"],"prefix":"10.3390","volume":"14","author":[{"given":"Wenfei","family":"Mao","sequence":"first","affiliation":[{"name":"Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China"}]},{"given":"Guoxiang","family":"Liu","sequence":"additional","affiliation":[{"name":"Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6532-9606","authenticated-orcid":false,"given":"Xiaowen","family":"Wang","sequence":"additional","affiliation":[{"name":"Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China"}]},{"given":"Yakun","family":"Xie","sequence":"additional","affiliation":[{"name":"Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9956-4380","authenticated-orcid":false,"given":"Xiaoxing","family":"He","sequence":"additional","affiliation":[{"name":"School of Civil and Surveying & Mapping Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7056-1124","authenticated-orcid":false,"given":"Bo","family":"Zhang","sequence":"additional","affiliation":[{"name":"Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8756-2211","authenticated-orcid":false,"given":"Wei","family":"Xiang","sequence":"additional","affiliation":[{"name":"Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China"}]},{"given":"Shuaiying","family":"Wu","sequence":"additional","affiliation":[{"name":"Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0809-7682","authenticated-orcid":false,"given":"Rui","family":"Zhang","sequence":"additional","affiliation":[{"name":"Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China"}]},{"given":"Yin","family":"Fu","sequence":"additional","affiliation":[{"name":"Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3177-037X","authenticated-orcid":false,"given":"Saied","family":"Pirasteh","sequence":"additional","affiliation":[{"name":"Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China"}]}],"member":"1968","published-online":{"date-parts":[[2022,5,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"101","DOI":"10.1016\/j.isprsjprs.2016.03.012","article-title":"An automated, open-source pipeline for mass production of digital elevation models (DEMs) from very-high-resolution commercial stereo satellite imagery","volume":"116","author":"Shean","year":"2016","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"109311","DOI":"10.1016\/j.measurement.2021.109311","article-title":"An approach for the precise DEM generation in urban environments using multi-GNSS","volume":"177","author":"Wani","year":"2021","journal-title":"Measurement"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"217","DOI":"10.14358\/PERS.71.2.217","article-title":"Urban DEM generation from raw LiDAR data","volume":"71","author":"Shan","year":"2005","journal-title":"Photogramm. Eng. Remote Sens."},{"key":"ref_4","first-page":"542","article-title":"Very high resolution optical satellites for DEM generation: A review","volume":"49","author":"Deilami","year":"2011","journal-title":"Eur. J. Sci. Res."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"333","DOI":"10.1109\/5.838084","article-title":"Synthetic aperture radar interferometry","volume":"88","author":"Rosen","year":"2000","journal-title":"Proc. IEEE"},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Del Soldato, M., Confuorto, P., Bianchini, S., Sbarra, P., and Casagli, N. (2021). Review of works combining GNSS and InSAR in Europe. Remote Sens., 13.","DOI":"10.3390\/rs13091684"},{"key":"ref_7","first-page":"8004605","article-title":"L1-Norm Sparse 2-D Phase Unwrapping Algorithm Based on Reliable Redundant Network","volume":"19","author":"Li","year":"2020","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"40","DOI":"10.1109\/MGRS.2018.2873644","article-title":"Phase unwrapping in InSAR: A review","volume":"7","author":"Yu","year":"2019","journal-title":"IEEE Geosci. Remote Sens. Mag."},{"key":"ref_9","first-page":"1","article-title":"Improved DEM reconstruction method based on multibaseline InSAR","volume":"19","author":"Zhang","year":"2021","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1314","DOI":"10.1109\/LGRS.2013.2238886","article-title":"Multichannel InSAR DEM reconstruction through improved closed-form robust Chinese remainder theorem","volume":"10","author":"Yuan","year":"2013","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"191","DOI":"10.1109\/TGRS.2008.2002644","article-title":"DEM reconstruction accuracy in multichannel SAR interferometry","volume":"47","author":"Ferraiuolo","year":"2008","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"2470","DOI":"10.1364\/AO.21.002470","article-title":"Analysis of the phase unwrapping algorithm","volume":"21","author":"Itoh","year":"1982","journal-title":"Appl. Opt."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"5217","DOI":"10.1109\/TGRS.2016.2558541","article-title":"Robust two-dimensional phase unwrapping for multibaseline SAR interferograms: A two-stage programming approach","volume":"54","author":"Yu","year":"2016","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"713","DOI":"10.1029\/RS023i004p00713","article-title":"Satellite radar interferometry: Two-dimensional phase unwrapping","volume":"23","author":"Goldstein","year":"1988","journal-title":"Radio Sci."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"813","DOI":"10.1109\/36.673674","article-title":"A novel phase unwrapping method based on network programming","volume":"36","author":"Costantini","year":"1998","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"666","DOI":"10.1109\/LGRS.2016.2535159","article-title":"An efficient minimum-discontinuity phase-unwrapping method","volume":"13","author":"Xu","year":"2016","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"2692","DOI":"10.1364\/JOSAA.14.002692","article-title":"Two-dimensional phase unwrapping with minimum weighted discontinuity","volume":"14","author":"Flynn","year":"1997","journal-title":"J. Opt. Soc. Am. A"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"698","DOI":"10.1109\/TIP.2006.888351","article-title":"Phase unwrapping via graph cuts","volume":"16","author":"Valadao","year":"2007","journal-title":"IEEE Trans. Image Process."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"338","DOI":"10.1364\/JOSAA.18.000338","article-title":"Two-dimensional phase unwrapping with use of statistical models for cost functions in nonlinear optimization","volume":"18","author":"Chen","year":"2001","journal-title":"J. Opt. Soc. Am. A"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"17","DOI":"10.1109\/JMASS.2020.3030862","article-title":"Baseline Design for Multibaseline InSAR System: A Review","volume":"2","author":"Yu","year":"2020","journal-title":"IEEE J. Miniat. Air Space Syst."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"478","DOI":"10.1109\/TGRS.2010.2055569","article-title":"A cluster-analysis-based efficient multibaseline phase-unwrapping algorithm","volume":"49","author":"Yu","year":"2010","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"494","DOI":"10.1109\/LGRS.2013.2270033","article-title":"A cluster-analysis-based noise-robust phase-unwrapping algorithm for multibaseline interferograms","volume":"53","author":"Liu","year":"2014","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1565","DOI":"10.1109\/LGRS.2017.2723050","article-title":"A refined cluster-analysis-based multibaseline phase-unwrapping algorithm","volume":"14","author":"Jiang","year":"2017","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"4251","DOI":"10.1109\/TGRS.2019.2962001","article-title":"A closed-form robust cluster-analysis-based multibaseline InSAR phase unwrapping and filtering algorithm with optimal baseline combination analysis","volume":"58","author":"Yuan","year":"2020","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_25","first-page":"1","article-title":"A phase slicing 2-D phase unwrapping method using the L1-norm","volume":"19","author":"Gao","year":"2020","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1059","DOI":"10.1109\/LGRS.2020.2991687","article-title":"Modeling-assisted InSAR phase-unwrapping method for mapping mine subsidence","volume":"18","author":"Dai","year":"2020","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_27","unstructured":"Simonyan, K., and Zisserman, A. (2014). Very deep convolutional networks for large-scale image recognition. arXiv."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"436","DOI":"10.1038\/nature14539","article-title":"Deep learning","volume":"521","author":"LeCun","year":"2015","journal-title":"Nature"},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Girshick, R., Donahue, J., Darrell, T., and Malik, J. (2014, January 23\u201328). Rich feature hierarchies for accurate object detection and semantic segmentation. Proceedings of the IEEE Conference On Computer Vision and Pattern Recognition, Columbus, OH, USA.","DOI":"10.1109\/CVPR.2014.81"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"14903","DOI":"10.1364\/OE.27.014903","article-title":"Phase unwrapping in optical metrology via denoised and convolutional segmentation networks","volume":"27","author":"Zhang","year":"2019","journal-title":"Opt. Express"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"54","DOI":"10.1109\/LSP.2018.2879184","article-title":"PhaseNet: A deep convolutional neural network for two-dimensional phase unwrapping","volume":"26","author":"Spoorthi","year":"2018","journal-title":"IEEE Signal Process. Lett."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"23173","DOI":"10.1364\/OE.27.023173","article-title":"Rapid and robust two-dimensional phase unwrapping via deep learning","volume":"27","author":"Zhang","year":"2019","journal-title":"Opt. Express"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"4862","DOI":"10.1109\/TIP.2020.2977213","article-title":"PhaseNet 2.0: Phase unwrapping of noisy data based on deep learning approach","volume":"29","author":"Spoorthi","year":"2020","journal-title":"IEEE Trans. Image Process."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"15100","DOI":"10.1364\/OE.27.015100","article-title":"One-step robust deep learning phase unwrapping","volume":"27","author":"Wang","year":"2019","journal-title":"Opt. Express"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1109\/TGRS.2020.3040277","article-title":"Deep Learning for the Detection and Phase Unwrapping of Mining-Induced Deformation in Large-Scale Interferograms","volume":"60","author":"Wu","year":"2021","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"4653","DOI":"10.1109\/TGRS.2020.2965918","article-title":"Deep convolutional neural network-based robust phase gradient estimation for two-dimensional phase unwrapping using SAR interferograms","volume":"58","author":"Zhou","year":"2020","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_37","first-page":"5216516","article-title":"Deep-learning-based phase discontinuity prediction for 2-D phase unwrapping of SAR interferograms","volume":"60","author":"Wu","year":"2022","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_38","first-page":"5212315","article-title":"CANet: An unsupervised deep convolutional neural network for efficient cluster-analysis-based multibaseline InSAR phase unwrapping","volume":"60","author":"Zhou","year":"2022","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"151","DOI":"10.1109\/LGRS.2004.843203","article-title":"Accuracy of differential shift estimation by correlation and split-bandwidth interferometry for wideband and delta-k SAR systems","volume":"2","author":"Bamler","year":"2005","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Brcic, R., Eineder, M., and Bamler, R. (2009, January 4\u20138). Interferometric absolute phase determination with TerraSAR-X wideband SAR data. Proceedings of the 2009 IEEE Radar Conference, Pasadena, CA, USA.","DOI":"10.1109\/RADAR.2009.4977112"},{"key":"ref_41","unstructured":"Brcic, R., Eineder, M., and Bamler, R. (2008, January 26\u201330). Absolute phase estimation from TerraSAR-X acquisitions using wideband interferometry. Proceedings of the 2018 IEEE Radar Conference, Rome, Italy."},{"key":"ref_42","first-page":"1371","article-title":"Deformation of the 2013 Pakistan MW7. 7 earthquake derived from sub-band InSAR","volume":"59","author":"Yu","year":"2016","journal-title":"Chin. J. Geophys."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"2245","DOI":"10.1111\/tgis.12825","article-title":"LiDAR point cloud and ICESat-2 evaluation of 1 second global digital elevation models: Copernicus wins","volume":"25","author":"Guth","year":"2021","journal-title":"Trans. GIS"},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Mare\u0161ov\u00e1, J., Gdulov\u00e1, K., Pracn\u00e1, P., Moravec, D., G\u00e1bor, L., Pro\u0161ek, J., Bart\u00e1k, V., and Moudr\u00fd, V. (2021). Applicability of Data Acquisition Characteristics to the Identification of Local Artefacts in Global Digital Elevation Models: Comparison of the Copernicus and TanDEM-X DEMs. Remote Sens., 13.","DOI":"10.3390\/rs13193931"},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Cenci, L., Galli, M., Palumbo, G., Sapia, L., Santella, C., and Albinet, C. (2021, January 11\u201316). Describing the Quality Assessment Workflow Designed for DEM Products Distributed Via the Copernicus Programme. Case Study: The Absolute Vertical Accuracy of the Copernicus DEM Dataset in Spain. Proceedings of the 2021 IEEE International Geoscience and Remote Sensing Symposium IGARSS, Brussels, Belgium.","DOI":"10.1109\/IGARSS47720.2021.9554393"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"5556","DOI":"10.1029\/2019GC008515","article-title":"The generic mapping tools version 6","volume":"20","author":"Wessel","year":"2019","journal-title":"Geochem. Geophys. Geosyst."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/14\/11\/2607\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T23:20:50Z","timestamp":1760138450000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/14\/11\/2607"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,5,29]]},"references-count":46,"journal-issue":{"issue":"11","published-online":{"date-parts":[[2022,6]]}},"alternative-id":["rs14112607"],"URL":"https:\/\/doi.org\/10.3390\/rs14112607","relation":{},"ISSN":["2072-4292"],"issn-type":[{"type":"electronic","value":"2072-4292"}],"subject":[],"published":{"date-parts":[[2022,5,29]]}}}