Novel antenna for improved mapping of structures
Conservation of historic masonry buildings is of primary importance for safeguarding the cultural identity of societies. Nevertheless, their maintenance, repair and rehabilitation is a very expensive process due to environmental reasons. Ageing, climate conditions, earthquakes, traffic vibrations and dead loads are some of the key causes of environmental damages on historic buildings and structures. The ONSITEFORMASONRY project focused on improving modern on-site investigation techniques for the structural evaluation and assessment of historic masonry buildings. On the basis of existing technology, a new high frequency radar antenna system with a centre frequency around 1.6GHz was developed. The diagnostic tool can be used for high-resolution non-destructive mapping of structures. The key innovation of this system is the separation between transmitter and receiver units both connected to the control unit. This flexible design enables conduction of both reflection mode and tomography measurements in cases where the transmitter and receiver need to be apart e.g. on a two-sided wall. Additionally, the new system has very small dimensions and is lightweight. Unlike other conventionally used antennas the system's resolution is very high, since the 1.6GHz antenna has a wavelength of about 6cm. Consequently, a very detailed mapping of structures down to only a few centimetres is feasible, while its bandwidth offers measurements of extremely high resolution. High resolution is also needed in other applications including measurement of asphalt thickness and detection of fractures in concrete. The novel system is very user-friendly and simple in its installation and use since it displays a very good combination of data collection and positioning. Offering a very short start-up time with calibration taking only a few seconds, measurements and control of data collection can be performed at the same time. Simultaneously to data collection, real-time visualisation of the antenna's movement path is provided via a robust attached monitor. Undergoing continuous lab testing, the high-frequency antenna system is offered for further collaboration with partners familiar with the application potential of this equipment. Possible areas involve forest research for precise estimation and diagnosing of the interior tree structure. Furthermore, other applications include estimation of moisture content in small samples of different materials, such as seed, corn, crop and sawdust.
