A data transmission system for aircraft is formed by a global transmission network that includes at least one subnet with at least one star distributor. The method is based on the hierarchical subband encoding process SPIHT that transforms the original set of picture elements into coefficients ordered by means of three ordered lists called list of insignificant sets, list of insignificant pixels and list of significant pixels. When subjecting an object which is close to the virtual camera to the predetermined processing which is implemented by a third processing and a fourth processing, the vertex processing section performs the third processing with a processing load higher than a processing load of the fourth processing, and the pixel processing section performs the fourth processing. A plastic substrate can be coated with the combined sol and the combined sol gelled to a thickness of at least 5 \u03bcm with heating to less than 150\xb0 C.