What difficulties will arise when stitching spectrograms?

Question

Signal processing

There is a budget SDR (Software Defined Radio) with a bandwidth (window) of 3 MHz. An analog signal is investigated in the frequency range of 10-30 MHz. I would like to get its spectrogram in this range, as well as observe its change over time. Is it possible to somehow combine individual spectrograms obtained at different window positions? Well, or even get the final spectrogram after "adding" signals from different windows. I am a layman in this topic, but I suspect that there will be some obstacles.