The method of vicarious calibration by means of calculated radiances allows absolute calibration of satellite radiometers in orbit. It works by comparing counts from the radiometer to be calibrated with corresponding absolute radiances, calculated from actual values of the relevant optically acting parameters of the atmosphere and the earth's surface. The method is applied to the VIS-channel (i...

In this paper simulation results of DLR’s ultra-wideband land mobile satellite (LMS) multipath channel model are presented. The goal is the evaluation of GNSS performance in the rail environment. For this safety of life (SOL) application an urban railway was identified as the most critical scenario. The channel model is based on a measurement campaign of the land mobile multipath channel perfor...

The future satellite communication systems are required to support the higher transmission data rate for providing the multimedia services by employing the efficient modulation method such as multi-level QAM. The employment of single carrier transmission with multi-level QAM would cause the fatal degradation of signal quality due to the non-linear amplifiers located at the earth station and sat...

There is a trend for mobile satellite system architectures aimed at the deployment of multi-satellite constellations in Non-Geostationary Earth Orbits (NGEOs). This allows the user terminals to be small size, low cost and having low power demand. In present and next generation satellite systems, CDMA has been proposed as the multiple access technique for a number of mobile satellite communicati...

Land mobile satellite communication systems at Ka/K band (30/20 GHz) are attracting more and more attention to researchers because of its frequency band availability and the possibility of using small earth stations and satellite antennas for the systems. However, the Ka/K-band communications also give significant challenges in the system design due to severe channel impairments expected from t...

Adaptive modulation is a powerful technique to improve the energy efficiency and increases the data rate over a fading channel. The ground station transmitter and the satellite receiver adapt the modulation scheme and the transmitter power to the state of the channel. In this paper, we study adaptive multi-level quadrature amplitude modulation (M-QAM) schemes for LEO satellite over a Rayleigh f...

This paper reports about the work of the 2003/2004 MSK2 project [1] at Ilmenau Technical University on streaming satellite services for In-Flight Entertainment (IFE). A simulation model was developed for planning, performance estimation and capacity dimensioning of satellite systems offering streaming services in long-haul aircraft flight scenarios. We focus on simulation aspect and describe in...

Univ.-Prof. Dr. Wolfgang Bösch Over the last decades Space and satellite technology has increasingly become part of our daily lives, be it regular weather forecasts based on satellite images, the multitude of TV channels distributed via satellites or the navigational GPS support we find in almost every car—not to mention the many other services and science missions that are based on modern sate...

To address Gram stain interpretation proficiency in a satellite/centralized microbiology laboratory paradigm, two programs were devised. In quality assurance program 1, nonmicrobiology technologists at satellite laboratories were required to interpret standardized Gram-stained specimens of clinical material prepared by an experienced microbiologist at a central laboratory. In quality assurance ...