Tikibirds

Sorry for reviving this old thread, but does anyone has that PPT saved? That website appears to be down. Francisco The Michigan Geocaching Organization is now hosting the presentation for me. You'll have to log in for a free membership to get it though... Go under the Main Menu on the left MIGO Documents -> Presentations. The two "Puzzle Solving Ones" are what you're looking for... Hope that helps! - Mike (Tikibirds)

Adding our voice to the many thanks - your site is deeply missed!

Thanks for all the nice comments! We are open to trades...please just contact us individually via the Forums or our profile if you are interested in a trade. If you would like to buy one, we can invoice you and we will give you a small discount if you purchase the set. Thank you for your interest in our Coins! Tikibirds

We're proud to announce our coin for our daughters (The Tiki-Twins): Some of you may have gotten to see these at the Midwest Geobash last weekend. Gold Edition Silver Edition Black Nickel GC trackable, custom "Pink birds" icon, and custom "TT" prefix. We designed this one to fit in most micro caches (matchstick conatiner, 35mm film canister, etc) so that a micro cache can actually hold a trackable. - we're asking $7.00 and $1.50 shipping (0.50 ea add) to anywhere. E-mail us at :renbrace@provide.net and we can Paypal invoice you or arrange something else. Hope you like it as much as we do! -Tikibirds

We do have a limited number of coins for trade so if you are interested in trading your personal coin with us, please feel free to contact us through our profile or the e-mail link above. Thanks! Mike and Ren Tikibirds

Our coin is 1.5" diameter 3.0mm thickness

We're proud to announce our new Tikibirds coin: Gold Edition Silver Edition GC trackable, custom icon, and custom prefix. It's our first geocoin - we're asking $9.00 and $1.00 shipping (0.50 ea add) to anywhere. E-mail us at :renbrace@provide.net and we can Paypal invoice you or arrange something else. Hope you like it as much as we do! -Tikibirds

Rusty gets my vote!

Yes, you will need a new one. I know that Trimble is selling the chips that support it, but don't have the hand-held packaging we like. I haven't seen anything yet from Garmin or Magellan. Garmin indicated they do not yet have a product for this (actualy their tech hadn't heard of it) and Magellan had no reply. I'd guess it'll be a year or so til something is available - however - the signal itself is not guaranteed yet and is only available on 1 GPS satellite right now.

First, I must apologize if you intrepreted my post as rude as that was not the intention. My job requires me to work with this stuff everyday so sometimes my descriptions get too technical, and sometimes too general as I try to leave out technical information. Perhaps the technical and or perhaps lack of technical information is somewhat missleading, as it appears I misintrepreted some of Peters information. Agreeing with Peter's additional information: Some of the key points I missed: - there is a subtile difference between establishing an initial fix, and maintaining one, I was referring to the initial condition. - Time is the most critical component of the solution. This is why 4 are required for an initial "lock-on". (The hand-held internal oscillators are usually accurate enough to "coast" for a second or two if signal is lost without any significat loss of accuracy.) - The GPS receivers have many "tricks" that they use when signal degrades (once the initial fix is established) - freezing altitude is one - I've also seen receivers "coast" based on present speed/heading. - among many others. This area is really the only difference between vendors (Garmin vs Magellan etc..) - I'm curious as to what parts of my description you are finding incorrect.. As I am certainly not the end all - be all of GPS experts, perhaps there's someting I'm missing or haven't explained enough...

Some technical insight: - Actually your hand held does know the distances to the satellites and the points of origination. All of the satellite positions are found using an "Almanac" (which is really math equation stuff) that is downloaded to your GPS every 12 minutes. The nature of the pseudo-random signal (which is a different signal from each satellite) is such that the exact transmision time and thus distance (at the speed of light) can be determined. The Atomic clocks are needed in the satellites as the time of transmision is what is so critical. Needing 4 satellites is really more a matter of geometry, and cross checking the different satellites against each other. - As for the initialization assumptions.. The display we're used to of Lat/Lon and Altitude are really conversions based on an internal system of earth/centered, earth/fixed vector representations. The conventional trigonometry in doing lat/lon breaks down in polar areas and around (E/W 180 degrees). If you've ever used UTM's you'll notice the GPS switches in less than a second. - As for 2D lock, guessing altitude does nothing to support a vehicle driving up/down a hill, or an airplane. The GPS really provides this (2D) indication as more of a user display of "I'm loosing accuracy". The entire global navigation system requires 3D + Time (which is really 4D) for anything to work. The hald held doesn't ever switch to a flat earth model. Altitude suffers first when signal is lost, especially while we are on the ground, because most of the satellites near the horizon are blocked by ground clutter. These satellites are geometrically needed for a vertical measurement (keep in mind everything is moving and vertical position is a measurement difference from acceleration due to gravity). - As for the civil vs military signals... There are actually two separate frequencies that are transmitted from each satellite. Right now, atmospheric distortion is the largest contributor to our handheld inaccuracy. Civil systems can only use one of these frequencies. Military systems use both. By measuring the same transmission on two different frequencies, the military receivers can far more accurately determine (and correct for) the effects of atmospheric distortion. The Civil receivers have to rely on a very complicated, yet not as accuracte model. There is however a new (third) signal that was just activated last december (L2C). There is only one GPS satellite currently on orbit that supports it, (along with the two brand new WAAS satellites), but it is intended for civil use, it'll be a year or two until the hand helds will be able to support it reliably, but it promises to greatly improve civil accuracy. The current military signal (P-code) is encrypted so you need the special dept. of defense secret decoder ring to decrypt it. - Right now, WAAS does a very nice job of measuring atmospheric distortion and sending the corrections to your handheld, so for now, use it, if you'd like improved accuracy.

Thought of one suggested improvement to the site... Since I've found it more enjoyable to cache with others, my suggestion is to modify the search/or pocket query with an attribute of "no selection/found/not found" by another cacher or two. Thus creating a cache list that a group of cachers all need together. - Tikibirds