{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T04:18:53Z","timestamp":1760242733702,"version":"build-2065373602"},"reference-count":47,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2016,5,11]],"date-time":"2016-05-11T00:00:00Z","timestamp":1462924800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100008702","name":"ESA","doi-asserted-by":"publisher","award":["Contract 4000103923-CCN 1"],"award-info":[{"award-number":["Contract 4000103923-CCN 1"]}],"id":[{"id":"10.13039\/501100008702","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100010198","name":"MINECO","doi-asserted-by":"publisher","award":["AYA2011-29183-C02-01"],"award-info":[{"award-number":["AYA2011-29183-C02-01"]}],"id":[{"id":"10.13039\/501100010198","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J. Imaging"],"abstract":"<jats:p>The Synthetic Aperture Interferometric Radiometer Performance Simulator (SAIRPS) is a three-year project sponsored by the European Space Agency (ESA) to develop a completely generic end-to-end performance simulator of arbitrary synthetic aperture interferometric radiometers. This means, on one side, a generic radiative transfer module from 1 to 100 GHz, including land and ocean covers, as well as a fully 3D atmosphere and Faraday ionospheric rotation based on variable TEC. On the other hand, the instrument can have an arbitrary array topology (number of antenna elements, and their time-dependent position and orientation). Receivers\u2019 topology can also be modified, starting from a very generic one to connecting and disconnecting subsystems, whose parameters can be individually configured. These parameters can be defined either by mathematical functions or by input data files, including the frequency and temperature dependence. Generic calibration and image reconstruction algorithms that are suitable for arbitrary array topologies have also been implemented, as well as tools to compute the instrument performance metrics, i.e., radiometric accuracy, sensitivity, angular resolution, etc. This manuscript presents the generic architecture of the SAIRPS, the algorithms implemented in the Radiative Transfer Module, and simulation results showing its performance. A companion manuscript (Part II) describes the instrument and calibration modelling, the image reconstruction algorithms, and the validation tests that were performed.<\/jats:p>","DOI":"10.3390\/jimaging2020017","type":"journal-article","created":{"date-parts":[[2016,5,11]],"date-time":"2016-05-11T10:53:59Z","timestamp":1462964039000},"page":"17","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Microwave Imaging Radiometers by Aperture Synthesis\u2014Performance Simulator (Part 1): Radiative Transfer Module"],"prefix":"10.3390","volume":"2","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9514-4992","authenticated-orcid":false,"given":"Adriano","family":"Camps","sequence":"first","affiliation":[{"name":"Universitat Polit\u00e8cnia de Catalunya-Barcelona Tech (UPC) &amp; Institut d\u2019Estudis Espacials de Catalunya\/Centre de Tecnologies de l\u2019Espai\u2014UPC, UPC Campus Nord, Building D4, Office 016, E-08034 Barcelona, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0031-0802","authenticated-orcid":false,"given":"Hyuk","family":"Park","sequence":"additional","affiliation":[{"name":"Universitat Polit\u00e8cnia de Catalunya-Barcelona Tech (UPC) &amp; Institut d\u2019Estudis Espacials de Catalunya\/Centre de Tecnologies de l\u2019Espai\u2014UPC, UPC Campus Nord, Building D4, Office 016, E-08034 Barcelona, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jorge","family":"Bandeiras","sequence":"additional","affiliation":[{"name":"DEIMOS Engenharia SA, Av. Dom Jo\u00e3o II 2, 1998-023 Lisboa, Portugal"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jose","family":"Barbosa","sequence":"additional","affiliation":[{"name":"DEIMOS Engenharia SA, Av. Dom Jo\u00e3o II 2, 1998-023 Lisboa, Portugal"},{"name":"RDA\u2014Research and Development in Aerospace GmbH, Rigiplatz 5, 8006 Z\u00fcrich, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ana","family":"Sousa","sequence":"additional","affiliation":[{"name":"DEIMOS Engenharia SA, Av. Dom Jo\u00e3o II 2, 1998-023 Lisboa, Portugal"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Salvatore","family":"D\u2019Addio","sequence":"additional","affiliation":[{"name":"European Space Agency\u2014European Space Research and Technology Centre (ESA-ESTEC), Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Manuel","family":"Martin-Neira","sequence":"additional","affiliation":[{"name":"European Space Agency\u2014European Space Research and Technology Centre (ESA-ESTEC), Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2016,5,11]]},"reference":[{"key":"ref_1","unstructured":"LeVine, D.M., and Good, J.C. (1983). 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