Sensor Web, Geoprocessing, Security & GeoRM, Geostatistics, Semantics, 3D, Ilwis, Earth Observation

Spatial Filtering and Time-dependent Sensor Descriptions for SOS

August 20th, 2013 @ 10:57 by Carsten Hollmann
Posted in 52°North, Sensor Web

We are pleased to announce that the 52 ° North SOS 4.0.0 implementation supports two new features: the SOS 2.0 Spatial Filtering Profile and the support for the optional validTime parameter in DescribeSensor requests. Both features will facilitate the modelling, storage and retrieval of mobile sensor data from SOS.

Spatial Filtering Profile

The Spatial Filtering Profile is specified in clause 12 of the SOS 2.0 specification (OGC 12-006). This profile restricts observations to spatial observations which provide a well-defined parameter for the observation location. This parameter carries the sampling geometry of the observation which represents the spatial extent where the observation result applies to and can be targeted by spatial filters. The “Spatial Observation” is defined in the Observation & Measurement 2.0 specification (OGC 10-025) subclause 7.13 and can contain any gml:AbstractGeometry type, such as points, lines or polygons.

Here is an example of a parameter with a point as the sampling geometry: (more…)

OpenSensorSearch – Midterm blog

August 2nd, 2013 @ 07:26 by MohammadYakoub
Posted in GSoC, Sensor Web


The aim of the OpenSensorSearch project is to provide a fast implementation of a sensor discovery server with the high performance of a Solr back-end. In addition, we are working on harvesting mechanisms for OpenSensorSearch to allow users to write harvesters for their own sensor data sources.
During this first term, I have had frequent contact with my mentors, twice a week on Monday and Friday. We stick to a Scrum-like methodology and rely heavily on test-driven development. The main considerations and tasks during the first half of the project runtime were:

  • Testing and extending the existing 52°North Sensor Instance Registry (SIR) implementation: Since the project builds upon the SIR implementation, it must  be carefully tested and extended for the OpenSensorSearch implementation.
  • Providing fast indexing and retrieving: The metadata indexing shall use the data fields supported by Apache Solr for fast indexing and retrieving.
  • Developing easy and open harvesting mechanisms: The harvesting mechanisms must be both easy and open to make it accessible to wide span of developers (more…)

Trajectory Analysis in R – Midterm Post

August 1st, 2013 @ 09:10 by JinlongYang
Posted in GSoC

This project aims to develop methods and classes specifically designed for trajectory analysis. Over the past five weeks, I have made progress in three main aspects.

First, I have been learning the basics of developing packages for R and making a transition from an R user (a.k.a. a useR) to an R developer. Second, I wrote a function for converting raw trajectory files into STI objects and eventually into STTDF objects. Third, I wrote an additional function to enable a simple spatial overlay operation between one or more STTDF object(s) and a SpatialPolygons object (from sp package), both at the individual point level, as well as at the trajectory level. (more…)