Beach Vs Land Programs: An Unmasking Conundrum

[ColonelDan]

I've been experimenting with V1.1 and developing a few custom programs to use on the beach and for relic hunting at our Seminole Indian War site.  In the process I came across an unmasking situation I can't explain...and neither can some other well experienced detectorists that I've contacted.

Using a clad quarter for the non-ferrous target and a small tent stake we always find on the beach for the ferrous target, I placed them on top of the ground side by side about 2 inches apart.  Both the Beach Sensitive and General programs were able to unmask the quarter...but that was just an air test.  The more authentic test would prove differently.

When the same targets were buried side by side in mild sandy soil, the coin at 6 inches and the tent stake at 1 inch, as we would normally find in the real world, Beach Sensitive could not unmask the coin no matter the settings I used while the General program was able to unmask the coin when discrimination was set at 4.6.  

In Beach Sensitive, I tried numerous combinations of sensitivity, salt sensitivity, bottle caps, reactivity, discrimination, silencer,  notch/no notch and audio filter in the 3 beach programs...again, with no success.  The quarter was always masked by the tent stake.  When the tent stake was removed, the quarter came through loud and clear with the expected TID  of 95-96.

Base Settings: 

General: Discrim: 4.6, Tone: Pitch, Bottle Caps: 0, Notch: Off, Sensitivity: 95, Max Freq: 40, Iron Vol: 7, Reactivity: 0, Audio Resp: 9, Threshold: 0, Audio Filter: 0, Tracking: on, Ground Stab: 2, Mag Ground: Reject, FE TID: Off

Beach Sensitive: All settings listed above, plus salt sensitivity, were varied to determine if anything made a difference.  No Difference.  The quarter remained masked.  

Non-engineer assumption by me and others:  This must be due to some software design that differentiates Beach programs from Land programs.  A difference that the user cannot alter or adjust.

Any ideas we may be missing would be welcomed.

Perhaps and hopefully an XP engineer will see this and help us out.  I'm obviously built too low to the ground since this conundrum goes right over my head.  🤣

 

[midalake]

Not going to be able to help. My beaches have little stacked or cluttered target issues. Over the years I have no need to test for masked targets. 

[ColonelDan]

8 minutes ago, midalake said:

My beaches have little stacked or cluttered target issues. Over the years I have no need to test for masked targets. 

We too have limited ferrous on our tourist beaches aside from ferrous bottle caps, which the bottle cap filter helps us avoid and tent stakes.  If we can't get this masking issued resolved, my hunting buddy and I will just play the odds and go with our custom Beach Sensitive program and hope for the best.  Notching out 0-10 does avoid many of the tent stakes and other occasional ferrous items that are few in number anyway.

[midalake]

2 minutes ago, ColonelDan said:

Notching out 0-10 does avoid many of the tent stakes and other occasional ferrous items that are few in number anyway.

I know many have said it is better to notch than use Disc. I am going to experiment with notching more when I get back on the machine. 
That said, I do Disc. at 22. This is due to the Black Sand Issues. Have not seen a negative impact of nonferrous target depth which I have done lots of testing on.
Maybe a higher Disc or notch would help? 

[Chase Goldman]

27 minutes ago, ColonelDan said:

We too have limited ferrous on our tourist beaches aside from ferrous bottle caps, which the bottle cap filter helps us avoid and tent stakes.  If we can't get this masking issued resolved, my hunting buddy and I will just play the odds and go with our custom Beach Sensitive program and hope for the best.  Notching out 0-10 does avoid many of the tent stakes and other occasional ferrous items that are few in number anyway.

So are you now using notch vice disc on your Beach Sensitive program?  Was the masking issue was less evident with notch vice disk?

[ColonelDan]

15 minutes ago, Chase Goldman said:

So are you now using notch vice disc on your Beach Sensitive program?  Was the masking issue was less evident with notch vice disk?

Neither Discrimination nor Notch made any difference with the masking issue.  Since no matter what we do anyway the masking will still be there, we just prefer silent search and not hearing the occasional iron.  If we can somehow overcome the masking one of these days, that would certainly be much preferred.   However, like you and I discussed, it seems this is a question better suited for an XP engineer to tackle.  😉

[Chase Goldman]

57 minutes ago, ColonelDan said:

Neither Discrimination nor Notch made any difference with the masking issue.  Since no matter what we do anyway the masking will still be there, we just prefer silent search and not hearing the occasional iron.  If we can somehow overcome the masking one of these days, that would certainly be much preferred.   However, like you and I discussed, it seems this is a question better suited for an XP engineer to tackle.  😉

Gotcha.  If you want to go silent, you can also use disc but with iron volume set to zero.  Don’t think it matters much either way, though and notch doesn’t require the extra iron volume adjustment step.  Sometimes disc helps with ferrous down averaging which can help with unmasking, but as you observed, it doesn’t seem to matter or help with Beach sens.  I will have to experiment with notch vs. disc at the beach.

[JCR]

I will suggest that the unmasking difference between the two programs has to do with how the SMF is weighted & processed. Even if you have the same max kHz setting,  the Sensitive program will favor the higher end of the spectrum as opposed to the General program.  Higher frequencies do not normally hit coins as hard but do hit ferrous harder than lower frequencies.  The 2D air test is not hard. The 3D in ground with 5" between  the 2 targets is hard for most any detector, even in mild soil.

I have experimented a good bit on at depth 3D masking. If ferrous trash, multi frequency is the way to go for sure. The lower weighted mix the better. There is also a sweet spot on reactivity/recovery and careful coil control is needed in interrogating a suspect target. I also find that being able to hear the iron and the higher conductor interact under the coil is helpful. TID will jumpy but not too wild.   Al trash and high mineralization is a whole other ballgame.

You may want to try using the lowest Max Freq possible on the Beach Sensitive(and General) and play with the Reactivity some more.

Let us know your results as this applies to all detectors and types of sites.

[Chase Goldman]

38 minutes ago, JCR said:

I will suggest that the unmasking difference between the two programs has to do with how the SMF is weighted & processed. Even if you have the same max kHz setting,  the Sensitive program will favor the higher end of the spectrum as opposed to the General program.  Higher frequencies do not normally hit coins as hard but do hit ferrous harder than lower frequencies.  The 2D air test is not hard. The 3D in ground with 5" between  the 2 targets is hard for most any detector, even in mild soil.

I have experimented a good bit on at depth 3D masking. If ferrous trash, multi frequency is the way to go for sure. The lower weighted mix the better. There is also a sweet spot on reactivity/recovery and careful coil control is needed in interrogating a suspect target. I also find that being able to hear the iron and the higher conductor interact under the coil is helpful. TID will jumpy but not too wild.   Al trash and high mineralization is a whole other ballgame.

You may want to try using the lowest Max Freq possible on the Beach Sensitive(and General) and play with the Reactivity some more.

Let us know your results as this applies to all detectors and types of sites.

JC - Dan relayed to me in some more detailed offline discussions, that it happens with all three base beach programs (i.e., dive, beach, as well as beach sensitive) regardless of the Max F setting used for each (i.e., he used all three Max F settings with each of the three base beach programs) and that he was able to unmask with General and other land based base programs regardless of the Max F settings. Agree that it’s more than just about Max F in the way SMF target signals are processed, but it appears that the Beach programs in general are doing something noticeably different than the “land” programs with respect to target signal processing even with otherwise identical user setting setups (other than the salt sensitivity setting which is only present on the beach base programs - and adjustment of which across its entire range had no effect on this masking behavior).  Also, in another thread, he noted different target response behaviors (primarily associated with TID differences) between beach sensitive and beach with identical user settings (including Max F), so that is consistent with your assertion that the SMF profiles and signal processing algorithms are different between outwardly similar programs (e.g., beach and beach sensitive) that goes beyond the SMF Max F user setting.

[ColonelDan]

53 minutes ago, Chase Goldman said:

Gotcha.  If you want to go silent, you can also use disc but with iron volume set to zero.  Don’t think it matters much either way, though and notch doesn’t require the extra iron volume adjustment step.  Sometimes disc helps with ferrous down averaging which can help with unmasking, but as you observed, it doesn’t seem to matter or help with Beach sens.  I will have to experiment with notch vs. disc at the beach.

I've tried the iron volume at 0 and various levels of Discrimination too...no success.  Good luck at the beach.  I sincerely hope you find the magic solution!🤣