## 5 Conclusions  
This research revolved around the presentation of a new, semi-automatic process, to determine the most locations for the colocation of GNSS CORS, with InSAR CRs in the framework of the establishment of strategic permanent infrastructures. The proposed methodology involves three major steps; the criteria were derived from the guidelines set by international authorities on GNSS and the current scientific literature on CR installation. Consequently, the criteria were used in the MCDA analysis to determine candidate locations. Finally, candidate locations were reduced by means of the 3D visibility analysis. The proposed methodology was successful in evaluating the framework of the CyclCOPS project, which involved the establishment of six permanent collocated GNSS CORS and dual CR stations. The evaluation process showed that the methodology is successful,and the results are fully aligned with the authority and scientific requirements set for the installation of such sensors. Conceptualization, C.D. ; methodology, D.K. and C.D. ; validation, D.K., K.F. and C.D. ; formal analysis, D.K. and K.F. ; investigation, D.K., K.F., G.M. and C.D. ; resources, C.D. and G.M. ; writing--original draft preparation, D.K. ; writing--review and editing, D.K. and C.D. ; visualization, D.K. ; supervision, C.D. ; project administration, C.D. ; funding acquisition, C.D. All authors have read and agreed to the published version of the manuscript. This paper is funded by the Cyprus University of Technology Open Access Author Fund. D.K. and K.F. were financially supported by the CyCLOPS (RIF/INFRASTRUCTURES/1216/0050) project ([[https://cyclops.cy](https://cyclops.cy)]([https://cyclops.cy](https://cyclops.cy)), accessed on 28 December 2021), which was co-funded by the European Union Regional Fund and Republic of Cyprus through the Research and Innovation Foundation. Not Applicable. * [PERSON] (2019) [PERSON] _Guidelines for EPN Stations & Operational Centres_; EUREF: Berlin, Germany, 2019; p. 16. * [PERSON] et al. (2019) [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON] _Introduction to Anubis Software for GNSS Quality Control in the GAGE Facility and NOTA_; UNAVCO: Boulder, CO, USA, 2019. * [PERSON] et al. (2013) [PERSON] [PERSON]; [PERSON]; [PERSON]; [PERSON] [PERSON]; [PERSON] [PERSON]; [PERSON] Characterisation of Corner Reflectors for the Australian Geophysical Observing System to Support SAR Calibration. In Proceedings of the ResearchGate, Edinburgh, UK, 9-13 September 2013. * [PERSON] (2017) [PERSON] On the Design of Radar Corner Reflectors for Deformation Monitoring in Multi-Frequency InSAR. _Remote Sens._**2017**, \(9\), 648. [CrossRef]
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