Instruments and Systems: Monitoring, Control, and Diagnostics Annotation << Back On the accuracy of a mobile node altitude determination on the basis of the data acquired from the network of distributed pressure sensors A.P. MOSCHEVIKIN In ideal case the object’s altitude over the sea level might be calculated basing on the atmospheric pressure value. Knowing pressure values simultaneously registered by two nodes and the absolute altitude of one of the nodes (the reference node), it is possible to calculate the unknown altitude of the second node. However, in reality the atmosphere is unstable and changeable. Its parameters differ not only between the layers, but also within one layer in different places. Therefore some corrections should be made. Obviously it is not reasonable to select a sensor to be a reference node if it is distanced by 1000 km, since climatic conditions might be substantially different. Is it possible to use the data from sensors separated horizontally by the distances of 100 m, 1 km, 10 km and/or spaced by 100 m or 500 m in vertical plane? This paper contains experimentally obtained recommendations on selection of the most appropriate nodes to be reference nodes for increasing the accuracy of altitude calculation. These recommendations were obtained on the basis of analysis of standard deviation of time series of differences between pairs of sensors with known locations. It was shown that in distributed pressure sensors the determination of the altitude with the accuracy of 1 meter might be achieved in some cases. Besides, typical characteristics of atmospheric pressure changes were registered. The experiments were carried out with the use of RealTrac access points equipped with BMP085 digital pressure sensors. Keywords: distributed pressure sensors network, atmospheric pressure sensor, altitude calculation, altitude measurement, local positioning system, localization accuracy, location calculation, wireless sensors network, atmospheric pressure changes rate. Contacts: E-mail: alexmou@rtlservice.com Pp. 59-70.