Thread: CHIRP in simple terms

I found this simplified explaination by Gil at THT ...(even I can understand this one)..

QUOTE...(in part):

The traditional sonar fires an single pulse at the specified unit kw per duty cycle.....that is just one single ping on your target.

Now..

The CHIRP fires a full band of pulses (from the "lower kHz" spec of the CHIRP band ...and up thru the "upper kHz" spec of the CHIRP band)...onto the target during one duty cycle.

Regardless of the wattage of each pulse..the total number of all these pulses puts a huge amount of energy onto the target...thus more energy onto the target the greater the return echo...per duty cycle.

Add to that ..the CHRIP system uses far superior processing to determine target information....called pattern matching...it memorizes the transmitted band and then compares it to the returned band echo... thus finding detailed target information.

All in all..CHIRP relies less on power of the unit and more on the overall CHIRP processing technology coupled with the higher quality transducers to achieve its results...

UNQUOTE...

(Some verbiage was intentionally changed by me because Gil was referring to a specific band xducer...with specific lower and upper frequency points..so I generalized it to fit any of the possible CHIRP band ranges)...

Rickie

Originally Posted by wipanfisher

So many choices! I rely want to see it in action. The chirp is for down and side imaging also correct? I think the hummingbird down imaging was better than the lowrance elite. Plus still two transducers?

Each brand's offering will be different in their respect to CHIRP...(as far as offering CHIRP in 2d, DI, SI, or a combination of any of those)...

Some will offer CHIRP "built in" the unit...some will require the additional "black box" to transmit the CHIRP signal...
Some units will be CHIRP only...some will be able to do CHIRP and regular "tone burst"...

It's important to understand that true CHIRP technology is a combination of 2 hardware parts...

1. The unit must be able to transmit this CHIRP signal "band of frequencies"....(and interpret all that return data)...
2. The xducer must be designed to vibrate at this CHIRP signal "band of frequencies"...

The big blue water brands have been offering true CHIRP 2d for some time now..(I'm not sure how long)...

There is also discussion about vague combinations of hardware regarding the CHIRP technology...

For example...the idea of a CHIRP unit transmitting a CHIRP signal thru a regular tone burst xducer is being called "baby CHIRP" or "Quasi CHIRP"...(I think this is what Fishton's latest experiment is doing with the Elite CHIRP unit transmitting the CHIRP signal thru the regular "tone burst" HDI xducer)...

CHIRP in DI and SI is new and unproven...so we shall see what transpires...

Definitely interesting...

Rickie