ADS-B Classification Using Multivariate Long Short-Term Memory

This analysis extends previous research that used long short-term memory–fully convolutional networks to identify aircraft engine types from publicly available automatic dependent surveillance-broadcast (ADS-B) data.

June 1, 2023

Air Force Institute of Technology, Wright Patterson AFB, OH

A high-level overview of how ADS-B works. (Image: Air Force Institute of Technology)

Over the last three decades, storage on the internet increased by over 40,000 percent from 15.8 exabytes in 1993 to 6.8 zettabytes in 2020. While it is difficult to determine the exact number, as of February 2022, the size of the internet is estimated to be about 21 zettabytes and is doubling every two years. If we assume the average personal computer (PC) has a hard drive of one terabyte, 21 zettabytes is equivalent to 21 billion PCs, essentially three PCs for every person in the world. While a lot of this data is personal data, a large portion of it is considered publicly available information (PAI) and can be utilized by any internet user or organization.

This increase in available data has resulted in the study of identifying trends (i.e., data analytics) becoming more and more prevalent in multiple facets of society to include commerce and government. Researchers and major corporations have considered multiple ways to best utilize this massive resource, aptly referred to as ‘Big Data.’ Some areas that have shown promise include Internet of Things (IoT) analysis, traffic modeling, flight and maritime movement, image recognition, search engines and natural language processing.

The increased focus on PAI and data analytics is recognized by military defense strategists who are responsible for making sound defense decisions. By incorporating PAI with the plethora of sensor data at their disposal, such as data from intelligence, surveillance, and reconnaissance platforms, it is possible to improve the predictive power of those resources. The need for data analytics is apparent in the United States Air Force and Space Force where multi-domain operations are integral to their defense strategies. In fact, the FY22 Posture Statement calls out Command and Control’s need for the translation and sharing of data to provide ‘real-time dissemination of actionable information’ to provide ‘joint warfighting across all domains at a pace faster than our competitors’. Without recent advances in technology, artificial intelligence, and machine learning, this goal would be virtually impossible. Fortunately, new techniques can be used to filter the noise in big data much faster than human speed to quickly make inferences that are important to military decision makers.

To aid military leaders with analyzing the immense data at their disposal, we seek to improve military operations by providing enhanced capabilities for a major user of big data: intelligence analysts. One focus area important to intelligence analysts is pattern-of-life (POL) modeling. Some researchers seek to improve POL modeling via machine learning. Recent research interests suggest analyzing ground-based and onboard aircraft sensors with deep learning to predict aircraft characteristics.

One stream of research for POL modeling is focused on exploiting automatic dependent surveillance-broadcast (ADS-B) data to make predictions about aircraft. Aircraft within certain airspace are required to broadcast ADS-B Out via an onboard transponder. The benefit of using ADS-B data for classification problems is that it is publicly available and aircraft flying in the USA and Europe are required to broadcast it in most classes of airspace. ADS-B data is collected from various sites worldwide where hobbyists and researchers maintain a receiver to collect it. ADS-B collectors submit their data to centralized repositories, such as the ADS-B Exchange, that aggregate the data for public use. In these repositories, both statistical and kinematic information about the broadcasting aircraft is available.

This work was performed by Richard Dill, Michael R. Grimaila and Douglas Hodson for the Air Force Institute of Technology. For more information, download the Technical Support Package (free white paper) under the Communications category. ARL-96554