rtl_power, 2Mhz step, 25-1825Mhz, 900 steps/53 (step/sec) = 17 sec full sweep.
rtl_fm 7,7 step/sec On 15.09.2014, at 14:18, Ben Hiett <[email protected]> wrote: > if you were wishing to use an rtlsdr to scan and identify signals across its > full tunable range, how long do you think it might take? > > It looks like the instantaneous bandwidth is about 2.4MHz, tunable range say > 50-1750MHz > > so you would have to look at the whole spectrum in about 700 chunks > > i've seen a wide range of times as to how long the stick takes to retune, > ranging from about 500 times a second (2ms) to 20 times a second (50ms) > > so it would take from 1.4s - 35s just to retune the 700 times > > I have no idea how long you would need to sample at each freq to be able to > have enough data to decide if there were a signal present within that 'chunk' > of spectrum > > I assume you would probably capture x s of IQ samples, run them through an > fft and then just look for peaks, i.e energy in a bin or bins exceeding some > suitable threshold. If I could get a feel for what x s would roughly be then > I could get a handle on my original question > > I guess the whole thing could be speeded up with some a priori knowledge of > where signals are likely to be, e.g. you may be able to skip parts of that > spectrum that you know won't have anything of interest in them > > but i would still be very interested to know how long it would take to look > at the 'whole-thing' as it were. > > apologies for the vagueness of the question, but i'm only really after a > vague answer for now.. i.e. ballpark in seconds say, or are we talking > minutes, hours or even days! > > I did see some of the rtl_power plots that seem to stretch to 24 hrs so maybe > it takes longer than i thought! > >
