Keynotes -- Spatio-Tempo-Social: Learning from and about Humans with Social Media -- Recent Advances in Worst-Case Efficient Range Search Indexing -- Design and Architecture of GIS Servers for Web Based Information Systems - The ArcGIS Server System -- Research Sessions -- Versioning of Network Models in a Multiuser Environment -- Efficient Continuous Nearest Neighbor Query in Spatial Networks Using Euclidean Restriction -- Discovering Teleconnected Flow Anomalies: A Relationship Analysis of Dynamic Neighborhoods (RAD) Approach -- Continuous Spatial Authentication -- Query Integrity Assurance of Location-Based Services Accessing Outsourced Spatial Databases -- A Hybrid Technique for Private Location-Based Queries with Database Protection -- Spatial Cloaking Revisited: Distinguishing Information Leakage from Anonymity -- Analyzing Trajectories Using Uncertainty and Background Information -- Route Search over Probabilistic Geospatial Data -- Utilizing Wireless Positioning as a Tracking Data Source -- Indexing Moving Objects Using Short-Lived Throwaway Indexes -- Indexing the Trajectories of Moving Objects in Symbolic Indoor Space -- Monitoring Orientation of Moving Objects around Focal Points -- Spatial Skyline Queries: An Efficient Geometric Algorithm -- Incremental Reverse Nearest Neighbor Ranking in Vector Spaces -- Approximate Evaluation of Range Nearest Neighbor Queries with Quality Guarantee -- Time-Aware Similarity Search: A Metric-Temporal Representation for Complex Data -- Adaptive Management of Multigranular Spatio-Temporal Object Attributes -- TOQL: Temporal Ontology Querying Language -- Supporting Frameworks for the Geospatial Semantic Web -- Short Papers -- Efficient Construction of Safe Regions for Moving kNN Queries over Dynamic Datasets -- Robust Adaptable Video Copy Detection.-Efficient Evaluation of Static and Dynamic Optimal Route Queries -- Trajectory Compression under Network Constraints -- Exploring Spatio-Temporal Features for Traffic Estimation on Road Networks -- A Location Privacy Aware Friend Locator -- Semantic Trajectory Compression -- Demonstrations -- Pretty Easy Pervasive Positioning -- Spatiotemporal Pattern Queries in Secondo -- Nearest Neighbor Search on Moving Object Trajectories in Secondo -- A Visual Analytics Toolkit for Cluster-Based Classification of Mobility Data -- ELKI in Time: ELKI 0.2 for the Performance Evaluation of Distance Measures for Time Series -- Hide & Crypt: Protecting Privacy in Proximity-Based Services -- ROOTS, The ROving Objects Trip Simulator -- The TOQL System -- PDA: A Flexible and Efficient Personal Decision Assistant -- A Refined Mobile Map Format and Its Application.

This volume constitutes the refereed proceedings of the 11th International Symposium on Spatial and Temporal Databases, SSTD 2009, held in Aalborg, Denmark, in July 2009. The 20 revised full papers presented together with 3 keynotes, 7 short papers, and 10 demonstration papers, were thoroughly reviewed and selected from a total of 62 research submissions and 11 demonstration submissions. The papers are organized in topical sections on spatial and flow networks, integrity and security, uncertain data and new technologies, indexing and monitoring moving objects, advanced queries, as well as on models and languages.