Relative height measuring device and method

The invention discloses a relative height measuring device which comprises a host computer, a microprocessor module, as well as an array type gas pressure sensor module, a power supply module, a liquid crystal display module and a serial port communication module which are respectively connected with the microprocessor module. A measuring method employing the relative height measuring device comprises the following steps: accomplishing a genetic algorithm optimized BP (Back Propagation) neural network in a host computer, transmitting obtained weights, thresholds and relative height calculation equations to the microprocessor module, acquiring gas pressure and temperature through the array type gas pressure sensor module and transmitting the gas pressure and temperature to the microprocessor module, processing the received air pressure and temperature through the microprocessor module so as to obtain the relative height, and transmitting the result to the liquid crystal display module to be displayed and stored in the host computer. With the combination of software and hardware, noise can be suppressed, useful signals can be recovered, enhanced and extracted, and the great precision and stability are achieved.