Satellites constantly gather vast amounts of data which need to be transmitted in a continual stream to ground stations for subsequent processing. Since satellites are only directly visible to ground stations for a few minutes each day, the time available for direct transmission is very limited. One way to address this problem is through data transfers via geostationary relay satellites. From their highly perched positions, these can maintain almost permanent contact to low flying satellites and simultaneously transmit continuous data to the ground station on Earth. As part of the GeReLEO research project, the Gäufeldenbased Steinbeis Innovation Center for Aerospace will be involved in the development of this type of communication system. The project is being backed by the Aerospace Agency of the German Aerospace Center (DLR) with funds from the German Federal Ministry of Economics and Technology (BMWi).
At the heart of this system is a modem based on a Field Programmable Gate Array (FPGA) for use on a Low Earth Orbit (LEO) satellite. This modem implements the algorithms for the adaptive transfer processes and uses a multi-beam reception antenna for the transponder on the geostationary relay satellite.
The Steinbeis innovation center will use an aerospace-suitable FPGA for the LEO modem. Unlike a processor, this offers a number of advantages in terms of configurability, speed, and data processing. Developing the modem firmware with the high-level programming language Handel-C allows for complex modulation and synchronization processes to be efficiently simulated and implemented in the hardware. Given the relative movement of the satellites and the resulting continual changes in their relative distances, it is important to have adaptive transmission processes that can adjust to current conditions. In addition, signal attenuation in the recommended Ka band is dependent upon atmospheric humidity and constantly fluctuates. The modem’s job is to select the algorithms for the transmissions channel in such a way that the data throughput rate is maximized while the error rate is kept below a specified limit.
The improved, channel-adaptive and broadband- efficient coding processes will be developed in cooperation between the DLR’s Institute of Communication and Navigation and the Technical University in Munich. Steinbeis experts will then implement these in an FPGA. After the technology has been successfully tested on the ground, a demonstration in orbit is planned. To carry out this demonstration, an aerospace-suitable modem will be constructed for a LEO satellite, and a transponder will be constructed for a GEO satellite. The Steinbeis Innovation Center for Aerospace will be responsible for the equipment needed for the flight hardware.
Dr. Michael Gräßlin | Prof. Dr. Felix Huber
Steinbeis Innovation Center Aerospace (Gäufelden)
su1319@stw.de
Technical lighting applications have undergone a growth spurt in innovation over the past ten years: Light diodes (LEDs) are used more and more in vehicles and general lighting systems. The development of these types of lighting systems relies increasingly on simulation processes. The Steinbeis Transfer Center for Applied Lighting Technologies supports companies in meeting the challenges raised by using LEDs.
This collaboration between the center and its customers often starts with an on-site training, in which the Steinbeis experts meet with the company’s employees to instruct on various aspects of LED lighting. This includes information about basic parameters and measurement methods for technical lighting and the general approach to designing LED lighting systems. In addition to these customized training courses, the center works with providers of specialty conferences, offering a broad spectrum of employee qualification options. As host of the International Light Simulation Symposium (ILISIS), the Steinbeis Transfer Center also networks with the most significant software providers for light simulations worldwide.
Technology transfer is also about using help to help oneself – customers are offered consulting services, but for the mid-term, internal development of LED lighting systems using the company’s own workforce is also an option.
Prof. Dr.-Ing. Alexander von Hoffmann
Steinbeis Transfer Center Applied Lighting Technologies Altdorf near Nürnberg
Alexander.vonHoffmann@stw.de