Underwater source localization in the presence of strong interference

The underwater localization of a broadband target in the presence of strong interference and noise has been widely investigated. A novel clutter suppression approach based on oblique projections is proposed, exploiting the prior information of the expected target response. The method uses a generalised likelihood ratio formulation to select the oblique projection best matching the measured data. The performance of the proposed method is verified through numerical examples and measured sonar data. The results indicate that the method provides good performance for time difference of arrival estimation and target localization under low signal to clutter ratio as compared to existing methods

RCA Strands as Scaffolds To Create Nanoscale Shapes by a Few Staple Strands

Thousands of nucleotide­(nt)-long single strand DNAs, generated from rolling-circle-amplification (RCA), were used as scaffolds to create DNA nanoscale wires and plates with a few short staple strands by following the origami design principle with a crossover at 1.5 turns. The core sequence of the circle template, for producing tens and hundreds of tandemly repeated copies of it by RCA, was designed according to Seeman’s sequence design principle for nucleic acid structural engineering (Seeman, N. C. J. Biomol. Struct. Dyn. 1990, 8, 573). The significance for folding the RCA products into nanoscale shapes lies in the design flexibility of both staple and scaffold strand codes, simplicity of a few short staple strands to fold the periodic sequence of RCA products, and lower cost