Prof. Y. Lupardi

Remember: drug tests are nowadays terrible sensitive . So: never touch anything that might contain drugs. When your boss tests your piss the next day you could be fired on the spot and labeled as a drug user!

That may not be as dumb as it sounds to us. I have been asked several times by some of the more suspicious and fiscally uptight people I know what my monthly fee is for using GPS. Maybe they associate it with OnStar or something. Besides, isn't the new European system going to be fee-based? Yes it uses the same business model als gc.com: only if you want specials you have to pay. F.i.: NAVSTAR-USA-GPS has free civilian use for info on the F1 frequency and the military use also F2 frequency. Galileo (the European system) will have F1 for free use but the services on F2 only for a commercial fee.

Thanks mtn-man for directing me to a place where I can ask my questions. I did not think about Magellan because nowhere on the cachepage or in the logs of REI GPS Hunt Game GCQ3XE (from tosmith who also made the event-cache REI Free Geo-Cache Clinic GCQ2YT) nor in the profile of this cacheowner the word 'Magellan' is found. The log from Amtracker on aug 17 answers a lot: 1. what happens on sept 26 is " REI—Huntington Beach Grand opening Aug 26-28! Welcome to Surf City's premier outdoor gear resource." 2. And the prizes are: "The first 200 people (age 12 and older) through the doors Friday, Saturday and Sunday will receive a special-edition water bottle and an REI gift card worth $5-$100."

Did anyone do yet the "REI GPS Hunt Game " cache? I like to know what this means in reality: "..where you will be entered to win some great GPS related prizes. " I ask this because it is a well know tactic in Europe but maybe not in the USA. What I mean is this: 1. did you have to fill in some form with name, adres and all kind of questions about your person that have commercial relevance for the organisers? 2. if so, did those forms contain small print telling you in positive words that you are signing away some rights? 3. what are those mysterious 'related prices'? Anything of value? 4. what happens where on the 26th as the logs indicate? Further: I will come back to this after the closing date of sept 16 . because the trick here in Europe is when you question the organisers about the winners: 'of cause there are winners but because of privacy reasons we cannot tell you who.' So you never come to know if it was all real.

Or maybe the list compiled by the military: GEOnet Names Server (GNS) containing about 34103 entries for Bangladesh.

At least I do. Yesterday I repaired my Monkey Wrench with it.

A nice secondhand Leica Multistation will cost you only 4000 euro making a nice reference station and a good rover such as Leica SR9400 goes for 2250 euro. http://www.lnrglobalcom.nl/site/products/second_hand.html

That is what I wanted to know also so I went working on it. And I made many tests. You can read all about in here: http://www.xs4all.nl/~atarist/geo/gps_accuracy.htm To summerize: after long observation times ( >1 hour) I managed to get to a few dm accuracy. And thanks for the 2 pdf-links. They were not know to me.

The first time in my life I met the word 'Caucasian' was 25 years ago when entering India and I had to fill in a form asking for my race (and also name/race/date of birth of my fathers mother and the like). I asked what to say and was told to write down 'Caucasian'. Never heard the word before in all my life in western Europe.

That asks for a home-experiment. I have taken a small compass and my good old GPS12. Without switching the GPSr on the needle reacts to it from a distance of 7 cm. When switching the GPSr on: exactly the same. Maybe there is some metal inside the plastic casing?

Inside a GPS reciever many kinds of frequencies are generated. An antenna is always two-ways physically speaking: because he can recieve he can also send. In whatever way you shield the GPSr components: the antenna will aways be able to leak frequencies to the outside world. And when a nearby GPSr picks these up they might create interference inside the GPSr with the there used frequencies. During an event when there were many GPSr available we found out that indeed some interfere on distances of <1 meters happens. As far as I remember it was a Magellan that disturbed some Garmin Etrex units but not all Etrex GPSr's that where there. So I always advice: keep the GPSr's separated at least 2 armlenghts.

The difference in numbers of geocaches/geocachers between France and Germany seems have to do with language/culture. There is a nice picture of caches: goto http://www.geocaching.nl/index/ and click on "Kaart van de Benelux" (top op page). You will see that Germany and the Netherlands have about the same density of caches. Also the Northern part of Belgium above the line Lille-Liège compares well with the Dutch and German distribution; in this part they also speek Dutch, a language of Germanic origin. In the south part of Belgium they speak French, a language belonging to the Latin languagegroup. And it seems that caches like to be near other caches; the distribution is lumped.

The question is valid. As with most other leisuretime activities there is no mirrorring of the population in whatever way you divide the population in groups. But how come? My mathematics are playing up. There are some neat models trying to explain this. http://ccl.northwestern.edu/netlogo/models/Segregation is a nice start. This project models the behavior of two types of turtles in a mythical pond. The red turtles and green turtles get along with one another. But each turtle wants to make sure that it lives near some of "its own." That is, each red turtle wants to live near at least some red turtles, and each green turtle wants to live near at least some green turtles. The simulation shows how these individual preferences ripple through the pond, leading to large-scale patterns. What will happen to this thread when I rephrase the question: Geocaching: A Christian sport?

Could this expanation also be valid for the following?: I have an Indian map (NC44-9) in Transverse Mercator projection with mapdatum spheroid Everest. It has a grid in British Yard I thought. But I forgot the scalefactor. (realisation) I am told. The normal yard is 0.9144m but the Indian yard on these maps seems to be 0.9143985m

Living in a very flat country we have the important question: "The water, where does it want to go to?" We made the NAP (New Amsterdams Peil) that gives us the 0-plane. With GPS we can also measure height above the ETRS89 ellipsoid but how to tie this in with the NAP? It was done by measuring the gravity in and around my country. A very big job but last year it came to fruitation. We now have the NLGEO2004 model and we hope it is accurate enough (0.35 cm sigma) to last for the next 10 years. After a policy decision all the NAP markers were adjusted to the new heights. The max differences found were 6 cm. They did not want the hassle with tables, interpolation and errorcorrection. Here is a picture where you can see what the height above the GRS80 ellipsoid is of the 0-level NAP plane. As you also can see: a 'gradient' of 1 cm/km is not exceptional.

When in the future there are GPSr's capable of centimeter accuracy for an unassisted standalone absolute position in the WGS84 frame then there is a problem with height: it varies because of tidal effects in the crust of the earth you are standing on.

The coming Galileo system will not use WGS84 but international standards like ITRF. Positions in your local system were measured in the past by triangulation. Now we can measure with GPS long baselines with very much more accuracy so all errors made in the triangulation process became measurable. Those are (in my small country at least) less than 1 meter. Whole areas are decimeters shifted wrongly. Your country will have the same kind of problem. It is a no-go to give everything a new position in the local grid. There are nice mathematics (7-parameter Helmert transformation, seven-parameter Bursa-Wolf transformation, Molodensky ) to convert between the local mapdatum and worldwide mapdatums with very good accuracy (centimeter wise). That is not the problem. But when the errors in the grid are known you can interpolate from tables what correction you have to use for your GPS-measurement to fit in with the environment. I use some 'official' sanctioned software (with the error-tables inside) to go from ETRS to local RD-Grid with centimeter accuracy. In the case under discussion: a mathematical conversion from a worldwide mapdatum to NAD with an accuracy of <1 meter will make only sense when the local grid-errors from the past are known.

In the Dutch forum we were talking about number of caches in areas. See the thread: Dutch Forum and here is the picture from Jowi:

Why does not someone put a webpage on the net where everyone can read how to set his type of GPSr to British Grid and back again. Every geocacher can then stuff a link on his cachepage to this document when searchers need to use OSGB In the Netherlands we have a likewise situation with the Dutch Grid complicated by the fact that many GPSr's do not know about Dutch Grid and users have to set all the parameters for the User Grid/Datum. For foreigners we have the document in English: http://www.xs4all.nl/~atarist/geo/gps_rd.htm Lately I get many questions like: "I have autonavigation with GPS in my car. How do I get those strange numbers called coordinates into this machine? I want to find a cache."

If all your maps are the same scale and format then you can glue them together with Image Arithmetic from http://www.t3i.nl/ Then when you have really big map you have to convert to ecw or tiled TIFF (or ozf2) to keep it useable. At least I cannot use 200 Mb png-files but 1.8 Gb ecw works !

Our new Dutch markers that are to be used by surveyers with their professional GPSr and have millimeter accuracy (and height) are made of a rod of stainless steel about 170 cm long that has a kind of shipscrew on the end. They are screwed into the ground. until the top is below the surface. Then a concrete protection with a lid is made. Like this one here that you see in use: http://www.geogames.nl/meetpunten/showgall...=200320&cat=511

Let me tell you something about in my country the Netherlands. It is very flat here and part is below mean sealevel. And yes, it is very muddy here most of the time in most places but we do not walk in wooden shoes to keep dry feet. We have rubber boots nowadays So height has some importance to us: where want the surplus water goto? A question of millimeters. Thanks to gravity measurement we now have RDNAPTRANS™ 2004 with a new geoide. In the past the measurement equipment was transported by train late in the evening and the stuff was setup on a railwaystation platform. This was the gravity station. When trains stopped travelling and industry came to relative rest then measurements were taken of something falling in vacuum with precise (atomic?) clocks for timing. Modern technical developments make it possible to transport the gravity station by road. (for British readers: there is also mention of a Gravity Station in Doctor Who) The result of all their work is this picture where you can see that water in the North-east of the country on a distance of 40.25 m above the WGS84 ellipsoid is in equilibrium with water in the south of the country on a distance of 46.25 above the WGS84 height. This over a distance of 200 km. NLGEO2004 (in meters) ten opzichte van GRS80 (ETRS89/WGS84)

Something like that. I can go: SEATTLE-AMSTERDAM FLY DRIVE SPECIAL: RETOUR & 7 DAYS CAR Rental for 480 EURO, That is myself bodily and 24 kg. luggage. How much charges UPS for 5 kg from Seattle to my door near Amsterdam? Should I fly to Seattle, pick up 24 kg of gc. goodies and then fly back; it could be just as expensive.?

Not being an American my choice of words is sometimes deplorable. I spoke with my eyes on the situation on the European continent. I would be mad to set up a gc goodiesshop here with UPS or another delivery service like that as the only transport channel. Most (85%) of my sales are less then 20 dollar in value. And require for postal stamps about 1,50 $ I do not sell any large goods that require parcelling. Like T-shirts or Antenna Balls. Let me make it less abstract. I buy at Groundspeak T-shirts. Long Sleeve Serial # T-Shirt for $15.99 The weight is 270 grams. So airtransportcost USA->EU adds (3 $c a gram) $8.10 I do not count custums costs. Then I have to pay sales tax (BTW, VAT, MwSt) of 19%. Raising the price to $27,13 Then I have to send. The box costs $1.50 and uninsured delivery with tracking costs euro 5,50 (=$6,89). Insurance adds another euro 7.50 (=$9.52) You see that this is madness. No one will buy for those prices. The same goes up for the Antenna Ball, only not so much airfreight costs. I have to box it to send it. Bringing the price of a single ball to deliver to $11.91 So my whole shop works without tracking, without insurance, without track recording and without UPS et all. to make shipping worthwhile. And yes, I would use UPC if I only had big parcels >5 kg and a value of >$250. But I have not. I can only think that things in the USA are very different from those in Europe and that Groundspeak has a very different position concerning the value and amount of ordered goods per costumer then I have.

Federal Bureau of Alcohol, Tobacco, Firearms, Explosives and Geocaching The same rule when there is a Cannabis Sativa growing on you property or a geocache hidden. Being drunk and smoking Cuban cigars they will point their firearms at you and use explosives to blow up the geocache.