I think he's talking about something like these.
www.amazon.com/RTL-SDR-Blog-RTL2832U-Software-Telescopic/dp/B00QFCNNV0

I'm not sure how much good it would do while moving due to battery life of a laptop. But while stationary, and if it could handle CTCSS tones and trunking, it would provide critical information well ahead of the radio.
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