Sonar: empire, media and the politics of underground sound

This article traces the development of acoustic navigation media, or “sonar,” in the first half of the twentieth century, focusing on the relationships forged between underwater sound, electric media, and new techniques of listening. The central argument is that sonar shaped, and was shaped by, the expansion of warfare and capital underwater, and that this expansion came to be conceptualized by nautical organizations as dependent upon the control of underwater sound. Through analysis of key episodes in the conquest of subsea space, the author explores scientific, military, and commercial efforts to sense underwater objects and demonstrates how these efforts helped reconceptualize oceanic water as a component of undersea acoustic media and led to the material reorganization of the ocean’s acoustic field. Cet article retrace le développement de médias acoustiques de navigation ou <> dans la première moitié du vingtième siècle en mettant l’accent sur les rapports créés entre les sons sous-marins, les médias électriques et les nouvelles techniques d’écoute. L’argument central de l’article est qu’il y a eu une influence réciproque entre le sonar et l’expansion sous-marine de la guerre et du capital, et que les organisations nautiques ont commencé à concevoir cette expansion comme nécessitant le contrôle des sons sous-marins. Au moyen d’une analyse d’épisodes clés dans la conquête de l’espace sous-marin, l’auteur explore les efforts scientifiques, militaires et commerciaux pour repérer les objets sous l’eau et démontre comment ces efforts ont aidé à réaliser une nouvelle conception de l’eau océanique comme composante des médias acoustiques sous-marins, menant à une réorganisation matérielle du champ acoustique de l’océan.

Network Optimisation and Performance Analysis of a Multistatic Acoustic Navigation Sensor

This paper addresses some of the existing research gaps in the practical use of acoustic waves for navigation of autonomous air and surface vehicles. After providing a characterisation of ultrasonic transducers, a multistatic sensor arrangement is discussed, with multiple transmitters broadcasting their respective signals in a round-robin fashion, following a time division multiple access (TDMA) scheme. In particular, an optimisation methodology for the placement of transmitters in a given test volume is presented with the objective of minimizing the position dilution of precision (PDOP) and maximizing the sensor availability. Additionally, the contribution of platform dynamics to positioning error is also analysed in order to support future ground and flight vehicle test activities. Results are presented of both theoretical and experimental data analysis performed to determine the positioning accuracy attainable from the proposed multistatic acoustic navigation sensor. In particular, the ranging errors due to signal delays and attenuation of sound waves in air are analytically derived, and static indoor positioning tests are performed to determine the positioning accuracy attainable with different transmitter–receiver-relative geometries. Additionally, it is shown that the proposed transmitter placement optimisation methodology leads to increased accuracy and better coverage in an indoor environment, where the required position, velocity, and time (PVT) data cannot be delivered by satellite-based navigation systems.

The Autonomous Pinger Unit of the Acoustic Navigation Network in EnEx-RANGE: an autonomous in-ice melting probe with acoustic instrumentation

The Autonomous Pinger Unit (APU) is an electro-thermal drill with acoustic instrumentation developed for the project EnEx-RANGE in view of a future space mission for the sub-surface exploration of Saturn's moon Enceladus. A main goal is the development of navigation technology for an acoustic guidance system allowing maneuvering a probe through glacial ice. In total 13 APUs were built and tested in terrestrial analog scenarios on alpine glaciers. The APUs form a spatially distributed network that defines a system of reference for the navigation of the maneuverable probe to a point of interest. The APUs have a novel melting head, slow control systems, and a modern system-on-chip (SoC) module that controls the probe and processes the recorded data. The APUs use acoustic emitters and receivers to measure the transit time of acoustic signals between them, allowing for the position reconstruction of all APUs by trilateration. Several auxiliary sensors monitor the internal state of the probe and assist the position estimation. With this instrumentation, the APUs have the ability of dynamically optimizing themselves within the network by changing their position. This paper gives an overview of the developed APU hardware and presents performance results from the field tests.

ENERGETIC CHARACTERISTICS OF LONG-RANGE UNDERWATER ACOUSTIC NAVIGATION SYSTEM FOR AUTONOMOUS UNDERWATER VEHICLES

Гидроакустические навигационные системы большой дальности действия (ГАНС БД) предназначены для высокоточного определения местоположения АНПА, выполняющих длительные миссии при значительных удалениях (до 500 км) от приемопередающих устройств. Создание таких систем связано с выбором структуры сложных сигналов при использовании гидроакустических маяков или излучателей, стационарно размещенных в прибрежной полосе вдали от района нахождения объекта навигации. На основе классического уравнения дальности гидроакустики решается оптимизационная задача, состоящая в определении точностных и энергетических характеристик М-последовательностей различной длины и отношении сигнал∕шум в зависимости от уровня излучения сигналов. Путем сравнительного анализа известных методов построения дальномерных навигационных систем большой дальности получены оценки достижимых отношений сигнал∕шум при различных вариантах построения схемы обработки для М-последовательностей различной длины. По экспериментальным данным рассчитываются отношения сигнал∕шум в точке приема сигналов при различных дальностях и типах сигналов. Показано, что оптимизация энергетических характеристик ГАНС БД, а также трактов приема и обработки сигналов достигается при использовании М-последовательностей средней длины (М = 127). Long-range underwater acoustic navigation systems (LR UANS) are used for high-precision positioning of AUVs during longstanding missions at significant distances (up to 500 km) from reference transceiver devices. The development of such systems involves the selection of the structure of composite signals when using underwater acoustic beacons or transceivers stationary located in a coastal zone far apart from the object of navigation. Based on the classic equation of the underwater acoustic range, it is possible to solve an optimization task, which involves accuracy and energy characterization of M-sequences of differents lengths and evaluation of signal-to-noise ratio with respect to emitting signals level. By comparative analysis of the known approaches to the design of long-range circular navigation systems, some estimates of achievable signal-to-noise ratio values were acquired for different techniques of processing the M-sequences of different lengths. According to the experimental data, signal-to-noise ratios in the reception point were calculated for different ranges and signal types. It is shown that the optimization of energetic characteristics of LR UANS along with paths circuits of signal reception and processing is achieved when using M-sequences of medium length (M = 127).

HYPERBOLIC NAVIGATION SYSTEM FOR PROVISION OF THE GROUP OPERATION OF MARINE ROBOTIC COMPLEXES

Навигационное обеспечение групповых операций морских робототехнических комплексов (МРК) предполагает одновременное (в рамках одного цикла работы навигационной системы) уточнение местоположения всех объектов МРК. Широко распространенная гидроакустическая навигационная система с длинной базой (ГАНС ДБ) не позволяет решить задачу, поскольку предполагает поочередную работу с объектами МРК. В работе рассмотрена задача обеспечения навигации объектов МРК при помощи разностно-дальномерной навигационной системы (РД НС). Исследованы два навигационных алгоритма, реализующих переборный и аналитический методы решения разностно-дальномерной задачи. Предложен метод применения РД НС с адаптивной конфигурацией для навигации объектов МРК в зоне акустической тени. Выполнены эксперименты, включающие компьютерное моделирование описанных алгоритмов и работу РД НС в натурных морских условиях, которые подтвердили работоспособность и необходимую точность разрабатываемой РД НС. Navigation guidance support of group operations of marine robotic complexes (MRC) assumes simultaneous (in the frames of one navigation cycle) positioning of all the objects of MRC. Widely used long-baseline underwater acoustic navigation system (LBL UANS) is not able to solve this problem, as it works with objects of the MRC sequentially. This paper investigates the problem of navigation guidance support of the MRC objects using a hyperbolic navigation system (HB NS). Two navigation algorithms that implement direct-search and analytical methods for solving difference-angefinding tasks are studied. The method of implementing HB NS with adaptive configuration was proposed for navigating the MRC objects in the acoustic shadow zone. The designed HB NS has undergone several experiments, including computer modeling of described algorithms and full-scale sea trials of the entire system operation, and thus proved its working capacity and the required accuracy.