radR: an open-source platform for acquiring and analysing data on biological targets observed by surveillance radar

<p>Abstract</p> <p>Background</p> <p>Radar has been used for decades to study movement of insects, birds and bats. In spite of this, there are few readily available software tools for the acquisition, storage and processing of such data. Program radR was developed to solve this problem.</p> <p>Results</p> <p>Program radR is an open source software tool for the acquisition, storage and analysis of data from marine radars operating in surveillance mode. radR takes time series data with a two-dimensional spatial component as input from some source (typically a radar digitizing card) and extracts and retains information of biological relevance (i.e. moving targets). Low-level data processing is implemented in "C" code, but user-defined functions written in the "R" statistical programming language can be called at pre-defined steps in the calculations. Output data formats are designed to allow for future inclusion of additional data items without requiring change to C code. Two brands of radar digitizing card are currently supported as data sources. We also provide an overview of the basic considerations of setting up and running a biological radar study.</p> <p>Conclusions</p> <p>Program radR provides a convenient, open source platform for the acquisition and analysis of radar data of biological targets.</p

Sound Finder: a new software approach for localizing animals recorded with a microphone array

Acoustic localization is a powerful technique for monitoring the positions, movements and behaviours of terrestrial animals. However, its prevalence in biological studies has been constrained by hardware and software that are custom-built, expensive and difficult to use. We recently helped to relieve the hardware constraint by describing a microphone array that is affordable, portable, easy to use and commercially available. Here, we help to relieve the software constraint by developing an acoustic localization program called “Sound Finder”, which is easy to use, freely available and accurate for a variety of animals and recording conditions. It runs in the free software environment R, and in spreadsheet programs such as Microsoft Excel and the open-source software LibreOffice. In this study, we describe how Sound Finder functions, and then test its accuracy by localizing natural sounds that were broadcast through loudspeakers and re-recorded with microphone arrays. We quantify Sound Finder's accuracy by comparing its location estimates with known loudspeaker locations and with output from other localization approaches. We show that Sound Finder generates accurate location estimates for a variety of animal sounds, microphone array configurations and environmental conditions. Furthermore, Sound Finder generates an error value that allows the user to assess its accuracy. In conclusion, Sound Finder provides accurate estimates of a vocalizing animal's location. It is easy to use, requires only widespread and affordable software and is freely available in a standard form as Supplementary material to this article