Thoughts on discrimination

[bklein]

I was using my CTX today and as usual getting annoyed at its ID characteristics. I first was at Cayucos beach. I was constantly getting hits that read as copper but were aluminum nuggets or iron. I was getting iron reversals that i had to back off the sensitivity to validate - and even then some were wrong.
Then later in the day I go to a kid's tot lot with bark material. I tried the various modes - beach, relic, and coins. I wanted - and expected to find one that gave good hard signals on coin targets but instead most targets were questionable - and deep. Many were under the black fabric barrier - so I just gave up. Already ~10" deep and no target yet. But copper ID so why go further- I'm kinda trashing the area.
So what it comes down to is.... How about we detect targets with a pi or whatever means but then spend more effort in the ID? Like then change to a different detection means with whatever frequency to better determine the target ID?
I am seriously wondering if it is worth spending the cash for a CTX if the ID is this hard. now switch to the GPZ-7000 and it seems same story. Go to Rich Hill and you get tons of metal trash. I don't want to dig a shoe tack at 22". Looks to me that we need/want to spend more time on the ID before we dig and switch detection modes to do so.

[Carl-NC]

I don't understand the need to add PI if target ID is the problem. PI tells you something is there, then you switch to disc mode which still can't ID targets at depth. If you want to improve target ID depth, adding PI doesn't do that unless you figure out how to make PI discriminate. At depth.

[bklein]

The PI mode finds the target as it seems best at it. Then switch to other modes to qualify the target - and spend more effort in the design to do so. For instance - if I am getting false readings between copper and iron cacn't the detector recognize this and work harder to determine the ID? You could have accelerometers monitor movement and realize centralization on a target and vary parameters etc. Two or more detectors in one.

[Carl-NC]

Let's say VLF will detect targets to 10", and ID them reasonably well to 6". There is 4" worth of desired TID improvement.

Now you add PI, and you can detect targets to 14". Suddenly you've added 4 more inches of desired TID improvement; you've doubled your problem. Adding PI did nothing to improve TID at depth, it just made things perceptively worse.

You either need to take current TID methods and improve them, of come up with a new method of TID. That might involve figuring out how to ID targets using PI, but that's not the same as adding PI to an existing TID platform.

An accelerometer could be a useful improvement for TID. Typically I hunt with a normal broad swing, and if I run across an interesting hit I re-sweep it with multiple short sweeps. An accelerometer could detect the change in sweep and switch to accumulating the multiple responses and doing correlation processing. Tesoro does this a little on the Cortes. An accelerometer could also modify filtering based on sweep speed to improve TID.

[bklein]

Yeah you got it. A VLF is usually preset to ignore iron or aluminum or pennies etc. but finds questionable targets anyway - or may miss good targets because of the presets. So turn all that stuff off, find the target, then determine what it is by varying sweep styles and smarter electronics.