Themes & Scope
A plethora of applications and devices that report their location generate massive amounts of spatiotemporal data, along with other useful information. These data can form trajectories with sequences of time-stamped locations; an arguably powerful representation model for unveiling the patterns of life, of humans, objects, or animals. The analysis of trajectories, however old, has recently taken a new twist, with the advent of big data that puts standard practices to the test. A subsequent concept of "big trajectories" would refer not only to high volumes and rates but also to enriched sets of trajectory data, when mixed with potentially independent data sources of additional values. The result of this blend can lead to more comprehensive and semantically significant objects than trajectories of time-stamped locations. Such enriched sets of trajectories, referred to as "semantic trajectories", promises novel solutions to application domains, such as transportation, security, health and environment and furthermore informs policy making. Big semantic trajectories, nevertheless, pose new challenges for the GIS, database, control and machine learning communities to tackle, revolving around the complete semantic trajectory analysis lifecycle: fusion, modeling, storage, analysis, etc.

After a previous special issue of SIGSPATIAL on semantic trajectories edited by Maria Luisa Damiani and Chiara Renso in 2015, research on the semantic trajectories flourished and new challenges and applications emerged. This SI therefore welcomes submissions on original research on semantic trajectories. While the community of the workshop MASTER2019 was held in conjunction with ECML/PKDD, the special issue aims to reach out to broader communities and is open to all researchers. Manuscripts should be submitted via the IJGIS ScholarOne and will undergo the regular IJGIS double-blinded peer-review process, following the same quality standards as the regular issues.

Topics
This Special Issue seeks to solicit original contributions that address a wide range of theoretical and practical issues related to semantic trajectories (especially big semantic trajectories) with strong geospatial emphases. Manuscripts lacking geospatial perspectives will fall outside the scope of IJGIS and will be unsuitable for the special issue. Some indicative topics are the following examples:

*Machine learning and Deep Learning with semantic trajectory data
*Spatiotemporal analysis for semantic trajectories
*Graph-based methods for semantic trajectory analysis
*Visual methods for semantic trajectories analysis
*Indexing methods for semantic trajectory analysis
*Methods for evaluation of semantic trajectory analysis, modelling and prediction
*Data models for semantic trajectories
*High-impact results from the fusion of trajectories with semantically-rich datasets
*Anomaly Detection, long-term semantic trajectory prediction techniques
*Infrastructures and systems to support the semantic trajectory analysis
*Big data issues in semantic trajectory analysis
*Semantic trajectories stream processing
*Context-aware movement analysis and contextual covariates of movement
*Influences of spatial uncertainty and spatial heterogeneity
*Applications of the analysis of semantic trajectories, e.g. in the area of smart cities
*Ethical, societal and privacy issues in the analysis of semantically rich trajectories


Important Dates
The following list provides an indication on the SI schedule dates:

Initial submissions by January 31, 2020
Decisions on the first submission by first half of April, 2020
Revised submissions approximately by beginning of June, 2020
Decisions on the revisions by July 31, 2020
If necessary, submissions of 2nd revisions by end of August, 2020
Decisions on the 2nd revisions by end of October, 2020
Submissions of final versions of manuscripts provisionally accepted by the special issue editors by end of 2020.
Accepted manuscripts will be published online in a week after the completion of proofs. Expected publications of the special issue in print: June 2021.
Submission Guidelines
All manuscripts are subject to the regular IJGIS double-blinded review process. For author instructions, please refer to Instructions for authors below. All manuscripts, including support materials, must be submitted using the journal's online Manuscript Central site, also below.

INSTRUCTIONS FOR AUTHORS SUBMIT AN ARTICLE

Please select "Special Issue Paper" when you reach the "Article Type" step in the submission process and indicate this special issue as the target issue. First-time users of the Manuscript Central site must register themselves as an Author.

Starting 25 August 2019, IJGIS is participating in FAIR (findable, accessible, interoperable, and reusable) data project among academic journals, so authors should share data and codes. Please ANONYMIZE your data and codes in Figshare (preferred) or Dryad and include a PRIVATE SHARING LINK (generated when you set up the data and codes at sites) in your Data and codes availability statement (see below). Please note that the private sharing link will expire in 12 months. If a revision submitted a year later, authors need to update the private sharing link.

The data and codes need to be sufficient to support the reproducibility and replicability of the research.

Add a section entitled "Data and codes availability statement" after the Conclusion section.

The data and codes that support the findings of this study are available in [repository name e.g “figshare.com”] with the identifier(s) at the private link (give the PRIVATE SHARING LINK, such as https://figshare.com/s/61d0851a0d08b8cb2b74). If you cannot share some data, please indicate and explain here specifically what data cannot be shared. For example, xxx data cannot be made publicly available to protect research participant privacy and consent (or state other reasons).


Guest Editors
Vania Bogorny, UFSC, Florianopolis, Brazil
Chiara Renso, Consiglio Nazionale delle Ricerche, Pisa, Italy
Stan Matwin, Dalhousie University, Halifax, Canada
Jose Antonio Fernandes de Macedo, UFC, Fortaleza, Brazil
Konstantinos Tserpes, HUA, Athens, Greece

Contact
For further inquiries please contact Vania Bogorny vania.bogorny@ufsc.br