Modem enhanced and synthetic vision systems (EYS/SYS) often make use of the fusion of multisensor data. Thus there is a demand for simulated sensor data in order to test and evaluate those systems at an early stage. We describe an approach for simulating Lidar sensors based on using modem computer graphics hardware making heavy use of recent technologies like vertex and fragment shaders. This approach has been successfully used for simulating millimeter wave radar sensors before. It is shown that a multi sensor simulation suite integrating such different sensors like millimeter wave radar, Lidar or infrared can be realized using principally similar software techniques thus allowing for a unified comprehensive simulator. This approach allows us to use a single consistent data base for multi sensor fusion. Recent graphics hardware offers the possibility of carrying out a variety of tasks in the graphical processing unit (GPU) as opposed to the traditional approach of doing most computations in the computer's CPU. Using vertex and fragment shaders makes these tasks particularly easy. We present a vertex shader solution written in GLSL, the OpenGL shading language. The program computes all necessary view transformations and shading information necessary for Lidar simulation in one pass. This allows high frame rates for real time simulations of even complex flight scenes.

In recent years the number of offshore wind farms is rapidly increasing. Especially coastal European countries are building numerous offshore wind turbines in the Baltic, the North, and the Irish Sea. During both construction and operation of these wind farms, many specially-equipped helicopters are on duty. Due to their flexibility, their hover capability, and their higher speed compared to ships, these aircraft perform important tasks like helicopter emergency medical services (HEMS) as well as passenger and freight transfer flights. The missions often include specific challenges like platform landings or hoist operations to drop off workers onto wind turbines. However, adverse weather conditions frequently limit helicopter offshore operations. In such scenarios, the application of aircraft-mounted sensors and obstacle databases together with helmet-mounted displays (HMD) seems to offer great potential to improve the operational capabilities of the helicopters used. By displaying environmental information in a visual conformal manner, these systems mitigate the loss of visual reference to the surroundings. This helps the pilots to maintain proper situational awareness. This paper analyzes the specific challenges of helicopter offshore operations in wind parks by means of an online survey and a structured interview with pilots and operators. Further, the work presents how our previously introduced concept of an HMD-based virtual flight deck could enhance helicopter offshore missions. The advantages of this system-for instance its "see-through the airframe"-capability and its highly-flexible cockpit setup-enable us to design entirely novel pilot assistance systems. The gained knowledge will be used to develop a virtual cockpit that is tailor-made for helicopter offshore maneuvers.

No abstract

Helicopter guidance in situations where natural vision is reduced is still a challenging task. Beside new available sensors, which are able to "see" through darkness, fog and dust, display technology remains one of the key issues of pilot assistance systems. As long as we have pilots within aircraft cockpits, we have to keep them informed about the outside situation. "Situational awareness" of humans is mainly powered by their visual channel. Therefore, display systems which are able to cross-fade seamless from natural vision to artificial computer vision and vice versa, are of greatest interest within this context. Helmet-mounted displays (HMD) have this property when they apply a head-tracker for measuring the pilot's head orientation relative to the aircraft reference frame. Together with the aircraft's position and orientation relative to the world's reference frame, the on-board graphics computer can generate images which are perfectly aligned with the outside world. We call image elements which match the outside world, "visual-conformal". Published display formats for helicopter guidance in degraded visual environment apply mostly 2D-symbologies which stay far behind from what is possible. We propose a perspective 3D-symbology for a head-tracked HMD which shows as much as possible visual-conformal elements. We implemented and tested our proposal within our fixed based cockpit simulator as well as in our flying helicopter simulator (FHS). Recently conducted simulation trials with experienced helicopter pilots give some first evaluation results of our proposal.