The aim of this paper is to measure distances between autonomous underwater vehicles using power LED as light source and photodiode as receiver in unknown light water adsorption conditions. The method is based on the attenuation of the light signal, depending principally on distance and water characteristics. In a previous paper, we proposed the use of a cheap power LED system to support acoustic devices in localization and configuration computation of an underwater robotics swarm. The idea was based on the exchange of light signals of different wavelengths, to reduce the noise, generated by LEDs; the unknown water conditions, affecting the light propagation, required a local measure of the absorption function \(a(\lambda )\) to obtain the distance between the source and the receiver. To avoid the use of many different wavelength LEDs, we investigated the influence of power and flash duration on the LED spectral emission. Starting from this experience, we are now able to measure distances without the unpractical local measure of the absorption function. In this paper we show as, modifying frequency, we shall be able to measure \(a(\lambda )\) and, consequently, the distance d.

本文的目的是在未知的光水吸收条件下，以功率LED为光源，以光电二极管为接收器，测量自动驾驶水下航行器之间的距离。该方法基于光信号的衰减，主要取决于距离和水的特性。在先前的论文中，我们提出了使用便宜的功率LED系统来支持声学设备进行水下机器人群的定位和配置计算的方法。这个想法是基于交换不同波长的光信号，以减少LED产生的噪声。未知的水条件会影响光的传播，因此需要对吸收函数\（a（\ lambda）\）进行局部测量以获得源和接收器之间的距离。为了避免使用许多不同波长的LED，我们研究了功率和闪光持续时间对LED光谱发射的影响。从这种经验开始，我们现在能够测量距离，而无需对吸收函数进行不实际的局部测量。在本文中，我们展示了通过修改频率，我们将能够测量\（a（\ lambda）\），从而测量距离d。