Hiromi Miyazaki

Measurement-Based Evaluation on Detection Probability of Extended Squitter for Air-to-Ground Surveillance

Deployment of Automatic Dependent Surveillance—Broadcast (ADS-B) has commenced worldwide for aeronautical surveillance. In ADS-B, an aircraft broadcasts extended squitters, which include its position measured by the Global Navigation Satellite System. These squitters are received by ground stations. ADS-B has the potential to achieve higher accuracy and higher update rates than conventional radar, however, they are vulnerable to co-channel interference. Therefore, evaluating the performance of extended squitters in real interference environments is crucial for successful deployment of ADS-B, the goal of this work. Our approach is to gather and analyze measurement data from four experimental ground stations in the Kanto airspace, Japan. The measurement data are practical as the sites include two major airports and an antenna tower supporting air-ground communication. Analysis of the data yields a measurement-based model that can estimate the probability of detection of the extended squitter for given link-margin and interfering signal rate. To the best of the our knowledge, this is the first work to derive an expression for the probability of detection based on large-scale measurements. Two applications of the model are demonstrated. First, the improvement on performance made possible by using a sector antenna instead of an omni-directional antenna is predicted; the contributions of improved link-margin and reduced interference are given. Second, the ADS-B coverage is predicted along an experimental flight route.

Evaluating Path Loss by Extended Squitter Signals for Aeronautical Surveillance

For the successful deployment of the aeronautical surveillance systems, it is important to select the appropriate path loss model that is used in the coverage design. While the flight experiment is a traditional approach to evaluate the path loss models, the passive measurement of the 1090-MHz extended squitters (1090 ESs) broadcast by target of opportunity is a new complementary approach. This letter examines the feasibility of the 1090 ES measurement for evaluating the aeronautical path loss models. First, the effect of the alternate transmission using two transponder antennas is removed to extract the effect of the propagation channel. Then, the measurement result during the flight experiment is compared to the reference values given by free-space path loss in order to show the relevance of using the 1090 ES.

Performance evaluation of a WAM system using measured range

Wide Area Multilateration (WAM) is a useful aeronautical surveillance system which is able to achieve high performance. However, WAM has a drawback in which position errors increase rapidly outside a constellation of receiver stations in principle. One of the solutions for the drawback is to apply a measured range between a receiver station and an aircraft to the Time Difference of Arrival (TDOA) localization. This paper describes test results of performance evaluation for a WAM experiment system using the measured range.

ADS-B security consideration in Japanese airspace from a technical perspective

ADS-B is a new means of aeronautical surveillance. Aircraft periodically airborne position, velocity, and identification squitters.

Detection probability estimation model for Wide Area Multilateration

Wide Area Multilateration (WAM) has commenced worldwide for aeronautical surveillance. WAM has potential to achieve better accuracy, probability of detection, and update interval than the conventional radars. However, the probability of detection and update interval have been barely investigated theoretically. Consequently, no guarantee exists that WAM is advantageous against the radars in the probability of detection and update interval. Also, receiver constellation has been designed by considering only the accuracy, which could be a too optimistic approach. Therefore, this paper presents probability-of-detection modeling. Because the probability of detection and update interval in WAM are interrelated, the proposed probability-of-detection modeling is also effective as update-interval modeling. The proposed modeling framework is obtained by connecting sub-models corresponding to the factors affecting the probability of detection, namely radio propagation, interference or FRUIT (False Replies from Unsynchronized Interrogator Transmissions in time), receiver, grouping, localization, signal rate, and filtering. Initial implementation and evaluation validate the modeling framework and derive the insights on future improvement.