Aerospace and Electronic Systems Magazine June 2017 - 2

In This Issue - Technically
STATE-OF-THE-ART SPACE MISSION TELECOMMAND RECEIVERS
This article is the result of a study promoted by the European Space Agency, aimed at research, design, development, and demonstration of a state-of-the-art receiver chain for telecommand (TC) links in space missions. The introduction of new, very powerful
low-density parity-check codes for error correction, recently approved for the TC standard, allows to operate at signal-to-noise
ratios significantly lower than those currently adopted. This implies a number of challenges for the receivers in terms of frame
synchronization, carrier acquisition, and tracking loops. Both the decoding and the receiver algorithms must be optimized as well,
in view of permitting efficient hardware and software implementations, while ensuring excellent error rate performances. All
these issues were faced in the present study through a fruitful co-operation between industry, research centers and universities.
This article presents a survey of the main results achieved, covering receiver enhancement investigation, simulation, implementation, and breadboard description.

AN INNOVATIVE TEST BED FOR VERIFICATION OF ATTITUDE CONTROL SYSTEM
In this article, an innovative experimental setup is presented for investigation of the attitude determination and control (ADCS)
subsystem of a satellite. This setup is based on the combination of some distributed modules of ADCS hardware in loop (HIL)
test bed and their data transmitting and synchronization. An air bearing platform simulates the attitude dynamic of the satellite.
Concurrently a sun simulator and a Helmholtz cage simulate the environmental conditions for sensors in two separate locations.
All of these parts work together in a synchronized closed loop and contribute for evaluation of the ADCS performance. Because
of the geometrical independence of components, there is no interference between different parts and therefore the development of
the system encounters minimum restrictions. Experimental results demonstrated the validity of the proposed experimental setup
and its capability in ADCS hardware in the loop tests by space sensors in the simulated environments.

ELIMINATION OF RESAMPLING ERRORS IN WIDE AREA MOTION IMAGERY (WAMI)
Resolution in wide area motion imagery (WAMI) is a key factor in image exploitation. The difference between a clear crisp
image, and a "soft focus" image can be the deciding factor in the extraction of usable information from the image. For tracking
purposes, it may be the difference between accurate tracking, and loss of tracking. A novel approach to projection of WAMI is
presented that results in zero loss of resolution. The Wright Patterson Air Force Base (WPAFB) 20091021 data set is used to study
the loss of resolution. The data set includes raw images and the projected images in National Imagery Transfer Format (NITF)
images. The raw images are compressed and compared pixel by pixel to the original images to measure the impact of compression. The results show there is considerable resolution loss in the conversion of the raw images to projected NITF images. There
is little loss due to compression. To preserve the resolution of the raw images, a novel approach to the projection process is
presented, and prototyped.

LITUANICASAT-2: DESIGN OF THE 3U IN ORBIT TECHNOLOGY DEMONSTRATION CUBESAT
The following article presents the design of the "LituanicaSAT-2" - an in orbit technology demonstration nano-satellite mission. The mission is a part of a network of 50 nano-satellites called "QB50" that will be launched in Q1-Q2 of 2017 to carry out
long-term measurements of key parameters and constituents of the lower thermosphere and ionosphere. Due to mission science
requirements, a standard 3U (30x10x10 cm) CubeSat had to be designed to maintain one of its faces aligned with the velocity
vector throughout the orbit with a pointing accuracy of +/-10 degrees. Design of the satellite sub-systems is described from a
holistic point-of-view with special focus on ADCS subsystem. An attitude propagator is developed to observe and validate the
satellite's dynamic response and steady-state behavior considering perturbing torques due to gravity gradient, solar pressure,
magnetic dipole and aerodynamic torques.

HISTORICAL ARTICLE: EARLY HISTORY OF POLISH RADARS
In this article, the early history of radar development in Poland is presented, from its origins in the 1920s when one of the founders of Polish radar technology, Professor Janusz Groszkowski from the Warsaw University of Technology, started his research in
radio-engineering technology. This research built a solid foundation for further development in the field of radar in Poland that
occurred throughout the decades of the 1930s and 1940s, development that slowed during World War II. The 1950s through the
1960s saw two decades of intensive development of different kind of radars. The most interesting technical solutions of which
are described in detail in this article. Thr history presented in this article ends in the 1970s, when a new era in radar development
in Poland began with a new generation of fully coherent radars using linear frequency modulation and pulse compression, as well
as digital signal processing.

STUDENT RESEARCH HIGHLIGHTS: QUADROTOR ELECTRONICS AND INTELLIGENT CONTROL
Unmanned Aerial Vehicles (UAVs) have seen diverse applications, including radiation or border surveillance, with quadrotors
offering small size, relatively low cost, high mobility, mass-production, and easy access to challenging environments. In addition,
quadrotors can carry sensors, cameras or other gadgets for information collection, data fusion, and subsequent actions of targets,
as was exemplified during the Fukushima nuclear plant disaster by visual and sensory surveillance or for an air delivery system.
In this article, we describe our project, the development and implementation of a practical, low cost, light-weight quadrotor electronics test platform designed to evaluate the FL closed-loop controller for roll and pitch stabilization.
2

IEEE A&E SYSTEMS MAGAZINE

JUNE 2017

Table of Contents for the Digital Edition of Aerospace and Electronic Systems Magazine June 2017