pisdr-image VS PiShrink

You could check out PiSDR. It comes with GNU Radio and GQRX already installed and has worked for me in the past.

A pi is essentially a small linux computer. You can either load a generic operating system like PiOS that is a linux distribution built to run well on a Pi, and then load application-specific software onto it like any other PC, or you can try one of the various packages that are more directly suited to RTLSDR uses with pre-loaded software like PiSDR.

This is the distro you are looking for: https://github.com/luigifcruz/pisdr-image

you are probably looking for PiSDR Using piSDR on two RPis since one year or more. You will find lot of tools, many devices supported, lot of ham apps ...

I would for sure load up this distro: https://github.com/luigifcruz/pisdr-image Pretty much everything you will ever need. (For a good long while). All optimized to run on a Pi.

There is a small utility, which shrinks the image by omitting the empty space. Then you can write it to any SD card, which the data will fit on. So in your case even on a 2GB card.

backup.sh - this is what makes the image and uses pishrink to shrink it

Depending on what single board computer you are using, you may want to look at PiShrink. This will at least allow you retroactively shrink the image you create to the actual amount of space used.

I was pretty familiar with most of this but I did not know about the "image backup" utility. You may also want to look at PiShrink in your process as well.

I run a full dd to create an image and then run pishrink https://github.com/Drewsif/PiShrink on it. I used to manually size the partition down with gparted and calculate how much to dd and then gparted the new card to expand the partition - too much work. Pishrink does all the work for you and is fast.