No abstract

The use of CubeSats promises several advantages within a low economical budget margin for different missions. Nowadays, data transfer through optical channels (lasercom) is considered a potential technology for satellite wireless communications, providing several advantages in terms of data transfer rate with lower energy consumption. However, a main drawback is the location of the Optical Ground Station (OGS). Therefore, an artificial vision algorithm for the processing of images captured by the camera of a CubeSat is proposed in this work, in order to carry out the identification and recognition of an OGS by means of a beacon signal, to aid the Pointing, Acquisition and Tracking (PAT) onboard subsystem for the communication’s stage.

CubeSat technology is a low-cost alternative for space research in universities worldwide, promoting research areas in tele-detection, Earth and space observation, telecommunications, meteorology, etc. In this sense, Attitude and Determination Control Subsystem (ADCS) plays a key role in order to achieve a fast and precise orientation of the satellite, aiding the system by acquiring the specific and critical angles they require to accomplish the space mission. Therefore, choosing adequate actuators is key for the correct manipulation of the CubeSat, and it must consider size, weight and electrical power usage limitations of the CubeSat Standard. ADCS actuators must generate a quick response to generate an active momentum that modifies the satellite attitude. This work proposes a speed PID controller for a reaction wheel using low-cost materials for its implementation in 1U CubeSats.

Peer-to-Peer (P2P) networks, as well as vehicular networks, have been extensively studied in the literature. However, the statistical characteristics of connection times among vehicles on the performance of a P2P network to allow Vehicle-to-Vehicle (V2V) communications have been largely overlooked. Specifically, the periods that vehicles remain connected to neighboring vehicles to directly communicate among them in different road characteristics (urban or highway) and road traffic conditions (low, medium, or high) are of main importance for the adequate performance of a P2P system. Indeed, these connection times establish the average number of peers and hence the bandwidth available in the communication system. These times have not been studied nor characterized before for the purpose of calculating the download probability and average download times, which are calculated in this work using a teletraffic analysis. We also present simulation results considering the CSMA/CA random access scheme established in the IEEE 802.11p communication protocol for V2V communications to investigate the effect of the random access protocol on the system performance.