One-dimensional double-base array is the most basic model of multistation passive positioning system. The study and analysis of this basic model can not only help to improve the design performance of the positioning system, but also help to improve the measurement accuracy of the positioning system. But so far, most of the researches on passive positioning system only arrange the mathematical equations from the perspective of solving the unknown quantity, without in-depth research on the internal correlation between each parameter. In fact, the one-dimensional linear array has many interesting inherent characteristics. Three intrinsic characteristics of one-dimensional double-base arrays are studied and given. Firstly, four methods of proving the midpoint direction finding solution on a single basis are described. Then, the arithmetic characteristics between adjacent paths are given. On this basis, some physical properties are briefly described. And then we can reveal the internal correlation between the difference of the path difference and other motion parameters as well as physical parameters. Finally, the median relationship among the three arrival angles and among the three radial distances is analyzed.
Keywords: Arithmetic characteristic, Arrival angle, Radial distance, Median relation, One-dimensional double-base array, Physical Characteristics, Radial distance, Single base midpoint direction finding.