Radio measurements are essential for the development of next generation wireless networks, which are expected to be multi-functional and handle a massive number of devices. Therefore, we present a flexible modular measurement framework based on ultra-wideband devices, which allows to measure the radio channels in widely distributed networks. In order to deploy a large number of network nodes, we have developed a memory-based synchronization and ranging protocol, that improves the temporal efficiency and reduces the load on the radio channel compared to state-of-the art ranging methods. The proposed modular framework is applied to a measurement campaign at an urban intersection measuring the radio channels between a meshed network of 16 static and one mobile node. Based on these measurements, we evaluate the proposed ranging procedure and show to achieve a mean distance estimation error of less than 0.3 m between static nodes, and of less than 1 m for an exemplary trajectory of the mobile node.