1. A method for synthetic reconstruction of an object exposed to a wave, starting from sensed signals produced by this exposure, and from a knowledge base, wherein the knowledge base comprises various filtering criteria, namely direct mode search criteria, criteria for extraction of the weak signals, criteria for identification in direct mode, three-dimensional observation grids linked to the illumination or reception angle of the wave, criteria for three-dimensional observation grids, three-dimensional reconstruction criteria, rules for optimization associated with the criteria for identification in direct mode, with the three-dimensional observation grids, with the criteria for three-dimensional observation grids, with the three-dimensional reconstruction criteria, and corresponding optimum criteria, following said optimization rules, and wherein the method comprises the following steps: extracting, from the knowledge base, direct mode search criteria, extracting, from the knowledge base, criteria for extraction of the weak signals, extracting, from the knowledge base, criteria for identification in direct mode and the associated rule for optimization, extracting, from the knowledge base, three-dimensional observation grids and the associated rule for optimization, extracting, from the knowledge base, criteria for three-dimensional observation grids and the associated rule for optimization, extracting, from the knowledge base, three-dimensional reconstruction criteria and the associated rule for optimization, extracting, from a set of sensed signals, filtered through the extracted direct mode search criteria, weak signals, extracting, from the weak signals filtered through the criteria for extraction of the extracted weak signals, weak signals of interest, removing the noise from the weak signals of interest so as to obtain useful weak signals, wherein if the rule for optimization of the criteria for identification in direct mode is satisfied by the useful weak signals, then: these extracted criteria for extraction in direct mode are optimum criteria for extraction in direct mode, update the knowledge base with said optimum criteria for extraction in direct mode, the extracted direct mode search criteria are optimum direct mode search criteria, update the knowledge base with said optimum direct mode search criteria, identify useful direct information, based on the useful weak signals filtered through the criteria for identification in direct mode, otherwise, change these criteria for extraction of the weak signals and reiterate the steps for extraction of these criteria, the steps for extraction of weak signals of interest, for removing the noise from the weak signals of interest to obtain useful weak signals, and for identifying useful direct information, and the step concerning the rule for optimization of the criterion, and if the rule for optimization of the criteria for identification in direct mode is not satisfied by the useful weak signals, then change these direct mode search criteria in the knowledge base and reiterate the steps for extraction of these criteria, the steps for extracting, from a set of sensed signals, filtered through the extracted direct mode search criteria, weak signals, for extraction of weak signals of interest, for removing the noise from the weak signals of interest to obtain useful weak signals, and for identifying useful direct information and the step concerning the rule for optimization of the criterion, if the rule for optimization of the three-dimensional observation grids is satisfied by the useful direct information, then: these extracted three-dimensional observation grids are optimum three-dimensional observation grids, update in the knowledge base, the three-dimensional observation grids with these optimum three-dimensional observation grids, reconstruct, based on the useful direct information filtered through the extracted three-dimensional observation grids, three-dimensional information of interest, otherwise, change these three-dimensional observation grids in the knowledge base, and reiterate the step for extraction of grids and the step concerning the rule for optimization of these new grids; if the rule for optimization of the criteria for three-dimensional observation grids is satisfied by the three-dimensional information of interest, then: these extracted criteria for three-dimensional observation grids are optimum criteria for three-dimensional observation grids, update, in the knowledge base, the criteria for three-dimensional observation grids with these optimum criteria for three-dimensional observation grids, reconstruct, based on the three-dimensional information of interest, filtered through the extracted criteria for three-dimensional grids, useful three-dimensional information, otherwise, change these criteria for three-dimensional observation grids in the knowledge base, and reiterate the step for extraction of the grid criteria and the step concerning the rule for optimization of these new criteria, if the rule for optimization of the three-dimensional reconstruction criteria is satisfied by the useful three-dimensional information, then: these extracted three-dimensional reconstruction criteria are optimum three-dimensional reconstruction criteria, update, in the knowledge base, the three-dimensional reconstruction criteria with these optimum three-dimensional reconstruction criteria, reconstruct, based on the useful three-dimensional information, filtered through the extracted three-dimensional reconstruction criteria, three-dimensional information for the object and determine a recognition state file, otherwise, change these three-dimensional reconstruction criteria in the knowledge base and reiterate the step for extraction of the criteria for reconstruction and the step concerning the rule for optimization of these new criteria.