The presented work analyzes the existing structure of data processing in airspace surveillance radar networks, which includes sequential execution of data processing stages (including signal processing and primary data processing stages). Based on the analysis, it is shown that the lack of inter-stage optimization leads to a decrease in the quality of data processing. Which in turn leads to a decrease in the quality of information support for consumers in the existing information network of airspace surveillance radar systems. The paper synthesizes an optimal structure of joint processing of signal data and primary processing data in airspace surveillance radar systems networks. The synthesized structure of joint processing of signal data and primary processing data allows implementing two methods of data processing: combining decisions at the level of data on detection of received signals from surveillance systems; combining at the level of making decisions on detection of air objects. The method of data processing by an airspace surveillance radar system, in which data are combined at the level of making decisions on detection of air objects for each signal data processing channel, ensures inter-stage optimization of network radar data processing and primary data processing. The proposed method has significant advantages in the quality of surveillance system data processing in comparison with the one currently used. This ensures an increase in the quality of information services for consumers of the considered information network of radar surveillance systems of airspace.