The rising research field of magnonics, which is named after the quanta of spin waves, represents a potential candidate for substituting electronic devices as information carriers at the nanoscale. [1-5] Nevertheless, data communication does not represent the only prospective route for magnonics. High-frequency radar systems get increasingly important, e.g., for autonomous driving. This requires very accurate and fast position tracking as well as communication with surrounding vehicles. [6] However, complex electronic building blocks for radar transceivers are vulnerable for nonlinearities at high frequencies and, thus, cause serious problems regarding reliable detection and communication. [6-9] With respect to higher stability, higher data throughput, and faster logic operations at frequencies above 10 GHz, magnonic circuits represent a very promising approach, which allows for substituting several electronic elements in current radar systems. [10] Radar sensors typically require a larger signal bandwidth than communication signals. Thus, high performance in both radar and communication applications requires fine-tuning of signals and advanced bandwidth concepts. Therefore, single-and multi-carrier waveforms between 20 and 30 GHz are very promising for increasing transmission rates and combining communication and sensing. [6] To this end, magnonic waveguides show outstanding characteristics for reliable multimode propagation, [11-14] which could define the backbone of magnonic building blocks in prospective radar applications. [3,15] In this work, we demonstrate the spatially and temporally resolved observation of spin wave excitation and propagation in such magnonic cobalt-iron (CoFe) waveguides at the nanoscale by time-resolved scanning transmission X-ray microscopy (STXM). The large saturation magnetization of CoFe results