The article reviews a method for constructing SDR-systems for receiving, demodulating and decoding automatic dependent surveillance (ADS-B) broadcast messages received from an aircraft in the context of unifying a software package for automated measuring stands built using virtual instrument technology and imitating board systems and real flight factors, including the radio environment.
The essence of the concept of a programmable radio is considered, which means that the basic parameters of the hardware components of the transceiver are determined not by hardware, but by the software indeed, opposite to the analog transceiver systems.
The essence of the technology of virtual instruments and virtual measuring systems, built on their basis, is revealed, their advantages are noted in relation to the construction of automated measuring stands. The definition of an automated measuring stand as a combination of software and computer facilities providing reproduction, modeling and measurement of high-frequency signals by means of a virtual device, is provided. This means a measurement tool implemented on the LabVIEW framework.
The article narrowly reviewes verification procedure and the essence of the technology of ADS-B, which allows the pilots and air traffic controllers at the ground station to obtain aeronautical information with greater accuracy.
The method of obtaining and transferring a demodulated message to the program part of the SDR-system for subsequent decoding is reviewed. The structure, types and kinds of broadcast messages, as well as the main GICB registers transmitted in ADS-B messages, are considered. The process of extracting information using a sample of position messages in the air coded by the Compact Position Report method is shown.
The obtained results allowed to conclude that unification of software together with software processing of demodulated information allows to significantly expand the range of messages received from the aircraft, for example, messages from a secondary surveillance radar or an airborne collision avoidance system without the need to upgrade and refine the hardware of automated measuring stands.