SWEPT-TIME DELAY CROS S -CORRELATION RADAR AT 2 4 / 2 8 GHZ

Radar applications can be found today in many sectors of the industry and the number of implemented systems will keep increasing over time. Detecting and measuring the distance of an object with more accuracy and reliability becomes a complex task as possible interference sources are increasingly being deployed. Frequency-Modulated Continuous-Wave (FMCW) radars, simple and commonly used in the automotive industry, for example, suffer significantly from neighbouring FMCW radars, as they can corrupt each other’s results and produce false positives or limit their ability to detect weaker reflections. This project aims at the improvement of an existing radio channel sounder, as well as transitioning the system into a radar topology for target identification. The modular radar architecture allows the integration of different Radio Frequency (RF) stages present in the research group. The radar implements the Swept-Time Delay Cross-Correlation (STDCC) technique of Pseudo-Noise (PN) sequences, where amplitude and Doppler information can be extracted from multipath components, characterising the radio channel obstacles. The radar parameters can be easily adjusted on-the-fly to the environment being measured. A new RF front-end was developed at 28 GHz using X-MWblocks from X-Microwave, a modular designing and prototyping system for RF products. The baseband sequence generation has been implemented into an all-digital Field-Programmable Gate Array (FPGA) based system and tested in a controlled environment against a Commercial off-the-shelf (COTS) FMCW radar

Characterisation of microbial attack on archaeological bone

As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved