What can a GPS do for Metal Detecting

[tomfg]

Just got a metal detector, and was wondering in what ways a GPS unit could be usefull to me. I don't have one yet, but would consider buying one if they sound useful. Will a GPS keep me from getting lost? Can I make a location in the woods, and be able to get back to it easy another day? What's the deal about "mapping"? A summary of what GPS can do would be great. Thanks!

 

[Bill W.]

I'd suggest you look at http://www.oziexplorer.com/ When you use OziExplorer and a GPS unit it can help you find locations such as old schools, houses, etc. that might be pretty hard to locate without GPS. OziExplorer/GPS can also help you go into areas that you don't know and track down possible sites with little knowledge of the area. To use OziExplorer you need to find older maps and import them into OziExplorer. Once you import them you need to calibrate the maps. Basically calibrating is picking 2 or more places (more is better) on the map and inputting GPS coordinates for known locations on the map. Once you calibrate the map you can select places of interest known as waypoints and upload them to the GPS to investigate. You can also use the OziExplorer/GPS on a laptop in your vehicle and see exactly where you are on the map at that exact moment. It's pretty awesome. If you live on the east coast early 1900's USGS maps can be found at http://historical.maptech.com/ For my area the maps are excellent. The show alot of old schools, churches and houses that are no longer there.

-Bill

 

[tomfg]

Bill, Thanks for your reply. The GPS units and mapping software sound really neat. Sound complicated as well.... I might have to enroll in a GPS 101 class! Can a person scan a plat map, say for a certain corner of a 40 acre plat, figure out the GPS coordinates somehow before hand, then head out in the woods and zero in on that location?
I live in Minnesota. Where does one get maps to use for the GPS units for my area? Thanks again, for your help! Tom

 

[Bill W.]

Actually it sounds more complicated that it is. Yes, you can scan a plat map and use it in OziExplorer. As long as you can idenify some KNOWN locations on the map to input coordinates into OziExplorer you can use any maps you can find. I use intersections mostly to calibrate my maps. The OziExplorer/GPS combo has helped me find alot of sites I would have otherwise just drove past because the site is just a field or something. One particular site I found was in the mountains in my area. I noticed it on a map and decided I would try to find it. I calibrated the map using intersections. I could get a mile away in my truck then I had to walk the remaining mile by foot. The GPS indicated the waypoint was almost exactly 1 mile away. I ended up within 50 yards of the foundation I had marked on the map. The closest calibration point was over a mile away because there wasn't anything to calibrate on closer. But, it worked wonderful and proved how useful the OziExplorer/GPS combo could be. I often calibrate a map of an area at home I want to investigate then go out using my OziExplorer/GPS hook into my laptop and watch where I am in 'real time'... I have found quite a few sites using this method too. I use http://www.maptech.com to get coordinates to calibrate a map in OziExplorer. That way I just head out in the truck and don't have to mess too much with inputting coordinates when I am scouting for new sites. If you don't have a laptop you can mark those places of interested as waypoints and use the GPS that way. Some images of that old site can be found at http://www.pbase.com/bellwoodmder/oldhome

I'd suggest if you don't understand some of the terms being used to look up 'GPS terms' on a search engine. I found this definition for waypoint...

Waypoints
Waypoints are locations or landmarks worth recording and storing in your GPS. These are locations you may later want to return to. They may be check points on a route or significant ground features. (e.g., camp, the truck, a fork in a trail, or a favorite fishing spot). Waypoints may be defined and stored in the unit manually by taking coordinates for the waypoint from a map or other reference. This can be done before ever leaving home. Or more usually, waypoints may be entered directly by taking a reading with the unit at the location itself, giving it a name, and then saving the point. Waypoints may also be put into the unit by referencing another waypoint already stored, giving the reference waypoint, and entering the distance and compass bearing to the new waypoint.

If you have any more question please feel free to ask. Believe me when I say it sounds very complicated but it's actually pretty easy.

-Bill

 

[Bill W.]

I did forget to say I have found http://www.hometownlocator.com/ a good source for sites such as old schools and parks in my area. If you use COUNTY (don't do city) and state. When the COUNTY web page loads click on the link that says 'Your County' County Physical Features & Cultural Features. Hope this helps...

-Bill

 

[Andrew Kalinowski]

Others in this forum can give you better advice on how GPS can be useful in metal detecting. But, you a quick run down of what a typical, consumer grade GPS receiver (GPSR) is capable of.

For starters, keep in mind that a GPSR is nothing more than a dumb piece of electronics that is smartly designed. It will not prevent you from getting lost but, it will help you to find the way in and the way out. OTOH, with a GPSR you are never truly lost, the receiver knows where it is, you just need to interpret and use this information.

The very basic function of a GPSR is to calculate its current position. This position is displayed on the screen as a set of geographical coordinates and / or as a point on a map.
The current position point can be recorded in the receiver

 

[tomfg]

Bill,
If I were to scan a plat map, and use a known GPS coordinate, such as
town center, and want to input a waypoint for a spot on the plat map
two miles away, how do you set up the scale of the map? I presume the
GPS unit needs to know this somehow for it's calculations.
The mapping software you pointed out didn't sound like it was USB
compatible yet. Are you using a serial connection or USB on your
unit? Any drawback of either at this time?
The "County" points of interest locater web page you sited is
interesting. I see those maps have longitude and lattitude markings
on them. Do GPS units read out in Long & and Latt?
Sorry for all the questions, but this GPS stuff has me intrigued.
Thanks, Tom

 

[tomfg]

Andrew, Thanks for the detailed information on GPS capabilities!
What I'd like to do, is find an old county plat map, say from
the 1930's, and use it to find some old homesteads that are
"no longer", and do some metal detecting.
Questions: Is this fesible?
What's the minimum software and hardware I would need to make this happen?
Such as,

Brand and model of GPS units
Mapping software
Etc.

Thanks! Tom

 

[Andrew Kalinowski]

Well, it

 

[Bill W.]

Tom,

First of all... there's absolutely no problem with all of the questions. That's why I ask for help on the forums here and that's why I try to help on the forums too. Using ANY map you are going to have to input a minimum of 2 calibration points. But, the more calibration points you can input makes the map more accurate. Also, when picking calibration points it's better to pick at least 4 calibration points at each corner of the map. Sometimes that is not possible and you can still get semi-decent results from just picking 2 points if the calibration points are close to the 'target' you are looking for. The scale is basically set by using the minimum 2 calibration points which OziExplorer can calulate the scale of the map.

I use a Garmin E-Trex Legend which is a serial GPS unit. But, I use a USB->serial cable and it works fine. The USB->serial cable is a very cheap purchase. Most popular models seem to be supported in OziExplorer. But, I would make sure before your purchase you GPS unit. I can only speak for my GPS unit. But, you can pick which format you want the GPS unit to display. All GPS units display long/lat but there are different formats in the display. You can pick Hour.minute.second or Hour.degrees ... Andrew can add to this if there more...

-Bill

 

[Andrew Kalinowski]

To keep things simple, you can get a receiver with USB interface.
For the co-ordinate formats. Beside latitude / longitude, one of the most popular is UTM. All current receivers support it.
2 points calibration works OK with a map that is scanned straight (no distortion) and with meridians horizontal. With more points, software can compensate for misalignments and distortions. More points = better compensation.

 

[Bill W.]

One thing I did forget that Andrew reminded me of in his post. If you have a known feature on your map but you can't find online at maptech.com or a compareable site. You can always go out to that point on the map and mark it as a waypoint or write down the coordinates then go back and use those coordinates as a calibration point. I would take Andrew's advise on GPS units. He has used many more units than me. That is not my area of expertise...

-Bill

 

[tomfg]

Thanks again guys. Sounds like it's time to start researching
brands and features! Tom

 

[capnron]

A GPSR can be a help in establishing a "pattern" in an area you are hunting. By marking finds, you can sometimes see a pattern develop which may indicate a lost road, or the orientation of a long gone building. Sort of like Ballard following the debris field to the Titanac. Productive areas often form a pattern if you display your waypoints on a computer.

Good Hunting / capnron

 

[tomfg]

Interesting concept about "establishing a "pattern" in an area you are hunting". Thanks.

I've been looking over the Garmin web page, trying to figure out what would be a
good begginer GPS unit that meets my needs.
Garmin's "GPS 60" unit, SRP of $192, is a non-mapping unit, with "Both serial and USB connections for fast and versatile download transfer"

What I'd like to do is be able to use some old maps, create "waypoints" for locations
I want to find, and be able to input them into the GPS unit, either via upload,
or manual input. Would Garmin's GPS 60 unit be able to do this?

I don't think I need a mapping unit that show's me graphically where I'm at on
a map....... at least not yet..... do I?

If I can upload waypoints into this unit, what kind of software would I need?
Garmins only, or would "others" software work?

Lastly, what does all the following info. from Garmin mean in plain English?

"Fast map transfer, with support for both USB and serial port interfaces; navigation instructions can be shared with repeaters, plotters, and autopilots using NMEA protocols through the dedicated serial port "

Thanks for your help! Tom

 

[Andrew Kalinowski]

[No message]

 

[tomfg]

Andrew,
I'm trying to get straight in my mind a point or two,
so please bear with me. If I buy a non-mapping unit,
such as the Garmin GPS 60, your saying the OZI software, etc.,
would be of no benifit because I couldn't upload the waypoints
from the software to the GPS unit... I guess I understand that,
but would the OZI software be benificial in itself to
create waypoints on an old map with no coordinates, in conjunction
with a modern map that has coordinates?

I'm not saying that I won't buy a Mapping unit, but I'm trying
to juggle cost, ease of use, and something that will do what
I want... just have to understand what that is!

For instance, If I have an old plat map from 1910 that shows
an old homestead out in the boondocks, in the NW 1/4 of the NW 1/4,
Section 24, etc., that I believe is no longer visible to the naked eye,
can I use the OZI software to create / plot some waypoints on the computer,
then manually input them in the GPS 60?

Would the Garmin eTrex Vista
http://www.garmin.com/products/etrexVista/
mapping unit work with OZI or other part software to upload my own maps?

Thanks again, Tom

 

[Andrew Kalinowski]

tomfg Wrote:
-------------------------------------------------------
> Andrew,
> I'm trying to get straight in my mind a point or
> two,
> so please bear with me. If I buy a non-mapping
> unit,
> such as the Garmin GPS 60, your saying the OZI
> software, etc.,
> would be of no benifit because I couldn't upload
> the waypoints
> from the software to the GPS unit... >>>>

NO NO nO nO

If you are getting non mapping unit than:
Ozi / TTQV and similar are GOOD for you.
You CAN transfer waypoints and between Ozi / TTQV and receiver.
With Ozi / TTQV you CAN use your old maps on the computer.

If you are getting non mapping unit than Garmin MApsource is of little (or no) benefit.
You could transfer waypoints and such but you could not use your old maps on the computer.

If you are getting a mapping unit than:
Ozi / TTQV are still good for you because they let you work with the old maps.
and
MapSource is good for you because it lets you load Garmin compatible (not your old) maps to the unit.

Purely for metal detecting and working with old maps
Ozi / TTQV are better than OEM mapping software regardless of the receiver brand and make you use.

 

[tomfg]

Andrew,
Sorry, I mis-read your last reply.... seeing a comma instead of a period can make a lot of difference! I've been doing a little more studying or Garmin's GPS units.
The eTrex Legend, is a mapping unit, and the srp is only $182.

http://www.garmin.com/products/etrexLegend/

According to what I understand, it works with all MapSource CD's.

Will it work with the OZI software and allow me to load my old maps?

If all sounds well with this unit so it will do what I need, I think
I'll go ahead and order one before I ask any more questions.....
then of course, when I do get the unit, there could be a couple of
more questions! Much appreciated, Tom

 

[Andrew Kalinowski]

Now, your Garmin link is to Garmin Legend. Is that the unit you are asking now about?
You can load Garmin compatible maps into Legend.
You can not load your old maps into Legend.
Overall, it