Performance evaluation of two altimeters intended for euler angles measurement

This paper describes usage of two pressure altimeters to measure an airplane position angle, e.g. pitch or roll. The measurement relates to the properties of the standard atmosphere where the pressure descends with increasing altitude. The altitudes measured by two altimeters allow us to determine their mutual vertical difference. While we know the shortest distance between these two altimeters we can calculate the required positional angle of an airplane. There are multiple ways how to compose a measurement system using this principle. One possible solution is based on two absolute sensors. In this case the precision of the pressure sensors is the crucial parameter. In this article we describe sensor modules with wireless interface using two types of sensors and we evaluate their performance for the proposed position angle measurement application. There are two types of sensors compared in the article. First of them is a cheap MEMS sensor LPS001DL provided by ST microelectronics with no certification for aerospace applications and the second is an SP82 manufactured by Memscap company which is often used in digital altimeters (Air Data Computer) for aerospace applications. The article describes the wireless measurement modules, the data interface, the mechanism used for data exchange with a control station and the measurement results that are statistically analyzed and compared with expectations. The article summarizes technical and economic advantages and disadvantages of this method of positional angles measurement and their applicability for aviation.