## 4 Discussion of the Results Analysis: First Findings on Trends and Best Practices
### Main Findings for the Grey Literature Sample
#### 4.2.2 Satellite Remote Sensing  
The same situation seems to have applied to \"Satellite Remote Sensing\", given that the same author [51] also reported that in Poland, _\"satellite images are known only via Google Earth(tm) and are not deemed to be especially useful\"_. Most of the users limited _\"their understanding of the data to the observational level and consequently their expectations are mostly intuitive\"_, and, as a consequence, for years, there was _\"a lack of deeper understanding of the potential and limitations of remote sensing methods and data\"_[35]. A proof that the situation is gradually evolving anyway and that the national community may be quite diverse in the adopted methodological approaches and technological maturity can be found in recent publications wherein satellite RS data have been used in support of heritage management [53]. With respect to the degree of users' uptake of \"Satellite Remote Sensing\" and its being embedding in their daily workflows, the same limitation as the one described above for \"Aerial Photography\" applies to the technical recommendations and guidance documents that were analyzed. However, some documents are also quite informative to understand the barriers that users perceive as obstacles to the access and use satellite data. For example,in [29], [PERSON] states that as of 2019, satellite images were not used in the Aerial Investigation and Mapping (AI&M) projects carried out by Historic England (and its predecessors). The author highlights, in order, the following barriers: spatial resolution, image purchase cost, and challenges in collecting cloud-free images. It is therefore evident that the author is exclusively referring to very high-resolution satellite images collected in the visible bands. [PERSON] [29] acknowledges that _\"the key advantage of satellite data, over and above the possibility of capturing data over very large areas at any given time, is the fact that most of the recent satellites possess sensors beyond the visible spectrum\"_ and envisions the potential to use multispectral imagery to detect cropmarks. Nevertheless, the conclusive remark is that, even if satellite imagery were _\"incorporated into AI&M projects in the future [...], this will require an assessment of the cost and time outlay compared with the usefulness of this source [...] and a degree of training\"_. This end-user perspective is highly interesting, given that it echoes similar considerations that are found across several scientific papers published by archaeologists and heritage professionals [54; 55; 56]. Furthermore, the above barriers and actions that are supposed to facilitate effective user uptake substantially match with those that previous review papers have highlighted [4; 6; 11; 12]. In this respect, another mechanism enabling the user uptake of satellite and geomatic technologies is multidisciplinary collaboration. The analysis of the Grey literature proves the role that experimentations and technological transfer may play, especially when heritage bodies are receptive to (new) technological solutions. A demonstrative example is provided by the Archaeological Park of Colosseum in Rome. As reported in its dissemination publications [36; 37], the Park implemented a dedicated program of satellite InSAR monitoring to combine with the in situ network of diagnostic instrumentations to assess the condition of monuments and archaeological structures and, based on this information, plan maintenance and restoration activities. The InSAR deformation measurements showing either the stability or the motion of the monitored structures were included in the Web App system, namely SyPEAH, that was developed by the Archaeological Park itself as a tool for the effective activity of the programmed conservation of cultural heritage [57].