MEGA Imaging is HERE!

[rnvinc]

Ok,but help me out please.I'm I correct in saying that sweeping multiple frequencies has nothing to do with garmin range,out to 600ft nor does it help the detail that the humminbird is getting out to the 125ft range..?(DSP) or chirp,making the difference ,in these ,low cost recreational units?or is it something else? (I no I'm being annoying,but just trying to learn)....I would think ,transducer quality /and how well it's tuned to the unit plays a big role

Continuous wave Sonar (fixed frequency of any kHz) has compromise limitations ... the only way to collect more echo data is to increase the gain ... which, in effect collects more echo data ... and more noise ...

Sweep frequency Sonar (CHIRP) is not bound by the same scientific properties ... so there can be more effective power put into the water (to collect good data) ... without collecting more bad data (noise) ...

455kHz fixed vs 1200kHz fixed is bound by sonar physics that higher frequency attenuates in water faster than lower frequency ...

CHIRPING adds range effectiveness to each frequency choice (relative) by being able to get more power into the water without the detriment of also getting more noise collected ...

The Mega Imaging marketing diagram of 400ft for 455kHz and 125ft for Mega 1200kHz would indicate both of those being CHIRP ...

We don't see (that I've found) the marketing diagram (or specs) for those same frequencies set as fixed frequency ...

My unoffical guess at fixed frequency, we would see effective 455kHz range at about 240 (similar to previous 455kHz) ... and we would see 1200kHz fixed frequency at about 60-90ft ...

Note: Environmental conditions such as bottom density and water particulate play into range effectiveness also ...

And also Note: Advancements in new processing of these new units should, in itself, allow some better imaging even at fixed 455kHz and 800kHz over what we are accustomed to seeing ...

Rickie