Multispectral optical signatures of micro UAV: Acquisition and database for usage in a neural network

Small unmanned aerial vehicles (UAVs) are becoming more and more popular and also a challenge for civilian and military security. A UAV has to be detected first, but due to environmental condition (e.g. night or fog) the detection is impeded. To assess the threat of a possible hostile UAV, identification is helpful. If the type of UAV can be determined, information about size, payload, velocity and range can be given and countermeasures can be considered. Identification of UAVs can be more accurate using multiple spectral ranges at the same time. We present a systematic approach for acquisition of multispectral signatures in the field and in the lab, structured storage in a database and composition of partially synthetic images as training data for identification in an artificial neural network. We set up a multispectral camera system comprised of three imagers, in the visible spectrum, SWIR and MWIR. The cameras are externally triggered. This allows an image acquisition in the field with a synchronized video stream. In addition to that, high resolution images are made in the lab from different angles all around the micro UAV. A specific background is chosen, so it will be masked and with a given real world background image a partially synthetic image can be generated. These can be validated with data that was gathered in the field. Both are stored in a database, along with metadata, to allow access to particular data when needed. Synthetic images and signatures from the field can be used as multispectral training data for an artificial neural network to enable identification of a UAV.