The Geocaching Blog


Lessons from a $40,000 G.P.S. Device

Sunshot99 and ATMA with the $40,000 GPS device

Geocacher Jib Ahmad, Sunshot99, makes his living as a land surveyor.  His GPS device is literally his livelihood.  A land surveying website lists the occupation as the world’s second oldest job.  But it now has some of the world’s most modern, technical and costly equipment.

A $20,000 dollar home in Pennsylvania, USA (not GPS-enabled)

Jib says that the GPS device displayed above costs about $40,000.

Let’s add a little perspective to the price tag.

With the slumping housing market, $40,000 will not just buy you one house, but in some parts of the world it’ll buy you two houses (or more).

Jib was kind enough to answer a few questions about the five-figure device. He says the Global Positioning System is one of his favorite subjects.

Jib says, “I am a land surveyor here in Texas and this is not my personal unit. I use it for work.  I have never looked for a geocache with the unit – only verified coordinates with it.”

He says that the device’s accuracy is certified at two to three centimeters on a horizontal surface.

Two centimeters is about the width of a nickel.    Jib says he’s found the unit is generally even more accurate.

A nickel is about 2 centimeters across

He says, “This is a ‘survey grade’ system that would not be necessary or practical for most geocachers.”

But in case you’re interested, he has details. A lot of details. Jib says the device is made up of a base unit and a rover unit: “The receiver I was using is a Trimble R8 GNSS with a Ranger TSC2 Bluetooth data collector.  The receiver has an integrated antenna that is capable of tracking 44 satellites.”

At this point you may say, ‘Well there aren’t 44 U.S. GPS satellites out there.’   You’d be right.  This GPS device can also track signals from Russian and European Union global positioning satellites.

Up close with a $40,000 GPS device

He says, $40,000 doesn’t buy you any more of a geocaching joy. “To search for a geocache that was placed by a handheld GPS would not be much fun with a ‘survey grade’ GPS device.  The coordinates would have the standard handheld error of about 3 meters or 10 feet.  So really it would not give the ‘survey grade’ geocachers an advantage over other handheld cachers.  But for those that would place a cache with ‘survey grade’ equipment, the normal geocachers should have better luck depending on the accuracy of their own handheld unit.”

And Jib has advice for you to get the most out of your GPS device: “Geocachers may find that they can get a better signal and accuracy range by simply moving their body around.  In North America, the best direction for the GPS system is to have a clear southern horizon.  So, if you are having trouble, move around so that the southern sky is more visible.”

Sunshot99 helping ATMA establish coordinates for E - HABIT - Without Bed Bath & Beyond

He says his best advice is to know your own GPS device inside and out.  If you want to test its accuracy, you may have some luck in the Houston, Texas area soon.

Jib says, “I am in the process of getting permission from the U.S. Army Corp. of Engineers to set a benchmark/geocache in a Houston area park. The geocache will be a Mystery cache designed to show any cacher how to get different coordinates for the same point. Hopefully this will show them the standard error for their PND (personal navigation device).”

  • http://twitter.com/thisisaceace Andrew

    Er, those arrows are a bit more than 3 cm apart on my screen!

    [URL=http://img830.imageshack.us/i/27297248.jpg/][IMG]http://img830.imageshack.us/img830/6082/27297248.th.jpg[/IMG][/URL]

  • Joe

    Heh, you might want to eliminate the “three centimeters” line. Whitespace collapses in standard HTML rendering and you're not using non-breaking spaces either. And a “standard” display (resolution? DPI?) doesn't exist.

  • http://twitter.com/thisisaceace Andrew

    I'm worried that Groundspeak think someone wouldn't know how big 3cm is!

  • Teamatlas

    My husband is also a land surveyor. I have to hear all the time how we use “toys” to geocache with and not real GPSr’s. LOL

  • http://blog.geocaching.com Eric Schudiske

    —–> Good point. I deleted the reference. Thanks for eyeballing that. <——–

  • http://twitter.com/thisisaceace Andrew

    Er, those arrows are a bit more than 3 cm apart on my screen!

    http://img695.imageshack.us/img695/9840/8468816

  • Joe

    Heh, you might want to eliminate the “three centimeters” line. Whitespace collapses in standard HTML rendering and you're not using non-breaking spaces either. And a “standard” display (resolution? DPI?) doesn't exist.

  • http://twitter.com/thisisaceace Andrew

    I'm worried that Groundspeak think someone wouldn't know how big 3cm is!

  • Sunshot99

    This was a lot of fun to get out with ATMA and test his coordinates that were very close. Another good way to test your PND is to go out looking for benchmarks. “First Order” horizontal BM’s will give you an idea of how far off your device is.

  • ATMA

    This was quite a surprise when the opportunity came up to have our coordinates “adjusted”. Close is one thing but right on the money? Awesome!
    We joke around about it now being a good calibration/verification point but it really is. Along with the spot on coordinates, we received a great lesson and some fantastic history of how this unit works and about surveying in general. Jib had some great stories of his experiences in the field.
    This is one of our favorite cache hides and a good idea of Rhonda’s, along with the placement and container style.
    Thanks to Groundspeak for posting this neat article and it was good to know that Mrs. ATMA got so many photos and none of this would have happened without the help of our friends, Sunshot99.
    Tim & Rhonda
    ATMA

  • http://www.wheremyheartlives.com Drivingrein

    Very cool! We have just got started geocaching in Washington State and are learning all about our Garmin Oregon 550t.

  • stor2467

    omg good luck

  • http://www.drivengps.com/ handheld gps

    Hi,

    GPS devices is really helpful at every place

  • http://www.drivengps.com/ handheld gps

    Nice…………………………………


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