Atilla the Pun

quote:Originally posted by peter: 1) Your equation is missing a parenthesis and should read: Actual Distance = SQRT((WPT1A-WPT2A)^2+D^2) Thank you. I was in a hurry and missed that last close parenthesis when I recreated it. Also note that the D is actually the horizontal distance between the two waypoints. quote:2) Don't use the backtrack function since doing this will eliminate the timestamps needed to calculate the speed. The tracklog gives you positions, altitudes, and times of successive points and is all you need. [Your procedure assumes you have a record of the horizontal speed between each set of backtrack points and I don't know of any GPS rcvr. that stores that data.] Yeah, I was wondering about that as I was driving to work. But having the time of each waypoint makes it simpler. I also assume you mean "backtrack to route" function. quote:3) Garmin and Magellan rcvrs. should work about the same. Joe Mehaffey had a review with some screen shots showing that the Magellan receivers actually create more waypoints during a backtrack than the Garmins do. I would have posted a direct link but I couldn't find it right off. quote:4) In almost all cases you can skip all of this and just use the speeds shown by the GPS rcvr. directly without much error. A 30% grade is considered a steep ski run and on that grade the difference between horizontal difference and actual distance is less than 4.5%. And note that this assumes you're skiing straight down the run and not slalomming back and forth which would reduce the effective grade. If you know or can measure the grade then it's probably easiest to multiply the indicated horizontal speed by a correction factor (sqrt[(1+grade)^2]) to convert to actual speed. So for a 30% grade the correction factor is sqrt(1+.3^2) = sqrt(1.09) = 1.044. Now that's what I like, a simple answer. AtP

to finish my physics dissertation..... The corrected formula that should have appeared above is: SQRT((WPT1A-WPT2A)^2+D^2 where ^2 means to square the value before it. This is the actual distance traveled between each pair of waypoints. Now, since speed=distance/time, and the GPS will give us the straight horizontal distance between each pair of waypoints, we can calculate the time it took you to travel between each pair of waypoints. You have horizontal distance and horizontal speed so the time to travel to each waypoint is HorizontalDistance*HorizontalSpeed. And now, finally, since you have the time it took you to travel from waypoint to waypoint and (from the first formula) the actual distance between wayopints, you can simply plug those values into this formula: Speed=Distance/Time and adjust for the units of time you want to use. It is recommended that you use a Magellan Meridian Platinum for this since the Magellans create more waypoints on a backtrack than Garmins do, and the MeriPlat is the only Maggy I know of that has a barometric altimiter. All this is off the top of my head, sorry if I rambled. Someone please check my assumptions and see if I swapped an operation or something. Thanks, AtP PS Clear as mud now?

to finish my physics dissertation..... The corrected formula that should have appeared above is: SQRT((WPT1A-WPT2A)^2+D^2 where ^2 means to square the value before it. This is the actual distance traveled between each pair of waypoints. Now, since speed=distance/time, and the GPS will give us the straight horizontal distance between each pair of waypoints, we can calculate the time it took you to travel between each pair of waypoints. You have horizontal distance and horizontal speed so the time to travel to each waypoint is HorizontalDistance*HorizontalSpeed. And now, finally, since you have the time it took you to travel from waypoint to waypoint and (from the first formula) the actual distance between wayopints, you can simply plug those values into this formula: Speed=Distance/Time and adjust for the units of time you want to use. It is recommended that you use a Magellan Meridian Platinum for this since the Magellans create more waypoints on a backtrack than Garmins do, and the MeriPlat is the only Maggy I know of that has a barometric altimiter. All this is off the top of my head, sorry if I rambled. Someone please check my assumptions and see if I swapped an operation or something. Thanks, AtP PS Clear as mud now?

Ok, this stupid board ate my reply, again. I'm going to a text editor to finish this and repost. AtP

Ok, this stupid board ate my reply, again. I'm going to a text editor to finish this and repost. AtP

First clear your backtrack, make your ski run and then save your backtrack to a route. Next you will calculate your speed between each pair of waypoints by the following method. Use the pythagorean theorem to obtain the actual distance traveled (or at least a number that's good enough for Gov't work) and keeping in mind that the VDOP is much greater than HDOP (vert. & horiz. Dilution of Precesion, so the altitudes the GPS records are less accurate than the horizontal positions, unless you have a calibrated barometric altimiter in your GPS) then figure the original time the GPS was calculating your speed at by multiplying your speed by the (horizontal) distance between waypoints. WPT1A = Waypoint1Altitude WPT2A = Waypoint2Altitude D = distance between waypoint 1 and 2 SQRT = take the square root of... SQRT((WPT1A-WPT2A)

You post that you bought a new case the day after I saw this. AtP

There was apparantly a defect in one manufacturing run, if you take out the batteries and look into the SD card slot and you can see a yellow wire it is blocking the SD card from seating correctly. I don't know if this would cause the other symptoms you describe or not.... AtP

My vote was for six individual caches. This is assuming that they are about diverse subjects, different types of senic outlooks, etc. I don't want to drive 150 miles to see 6 different gysers. AtP

The old UBB used to have links to each page listed by/under the thread title. Many other BB packages do it this way, too. That's my 2nd choice. I really do like it all on one page (so I can do a ctrl+F one time to find what I'm looking for in the thread) but I recognize that not everyone has broadband at home. AtP

The old UBB used to have links to each page listed by/under the thread title. Many other BB packages do it this way, too. That's my 2nd choice. I really do like it all on one page (so I can do a ctrl+F one time to find what I'm looking for in the thread) but I recognize that not everyone has broadband at home. AtP

From the Old French of "to hide". AtP

I've downloaded one Quad from here and I can't remember if it has the grid on it or not. AtP

Oooops, my mistake. Thanks for setting me straight. AtP

My Map 330X (same antenna as the Meridain series) was getting much better signal strength than my friend's Vista while geocaching the other day. If you are comparing the Meridians to the Vista be aware that the Vista has an actual compass, only the Platinum has one with the Meridians. AtP

I like the Vista for the built in compass. don't get me wrong, you should carry a magnetic for backup, but most GPS "compass" only work while your moving, and they "orient" you in the direction you're moving, not the direction you're facing. When I stop to look for range and bearing to the cache if I turn with my Map 330X I don't know what way I'm facing. With my friend's Vista (with the flux gate compass on) we know what way we're facing even standing still. And only have one device to check, not two. That is why my next GPS will be either the MeriPlat or the 76S (unless I strike it rich and get a DNA!!!). AtP

quote:Originally posted by Zuckerruebensirup: I seem to be having trouble with using my windshield mount in combination with the GPSr wrist strap. If I attach the wrist strap, the GPSr apparently won't fit into the mount. If I remove it, the unit snaps right in. I can't figure out what I'm doing wrong. But it seems crazy that they would sell a "package deal" that you can't even use together. I don't want to have to remove and reattach the wrist strap every time I take my GPSr in my vehicle. Unfortunatly I think a 1/4" hole is going to be requred to use them both together. I've attached the DC/PC cable to the mount so I'm always bringing it back and forth to the house. I haven't attached the lanyard yet, but when I do I think a hole will have to be drilled in the mount. AtP

quote:Originally posted by Zuckerruebensirup: I seem to be having trouble with using my windshield mount in combination with the GPSr wrist strap. If I attach the wrist strap, the GPSr apparently won't fit into the mount. If I remove it, the unit snaps right in. I can't figure out what I'm doing wrong. But it seems crazy that they would sell a "package deal" that you can't even use together. I don't want to have to remove and reattach the wrist strap every time I take my GPSr in my vehicle. Unfortunatly I think a 1/4" hole is going to be requred to use them both together. I've attached the DC/PC cable to the mount so I'm always bringing it back and forth to the house. I haven't attached the lanyard yet, but when I do I think a hole will have to be drilled in the mount. AtP

My only problem with the Rino is that one of the big advantages of GMRS is you can put a better/external antenna on it. You won't be able to do this with the Rino. That removes alot of the advantage of GMRS. Also, what is the power output on this unit? Is it going to be the maximum for a GMRS handheld, 5W? Or will Garmin restrict the output to say 2W? Too many questions to make a real decision yet.... AtP Edit: I voted "Tempted" [This message was edited by Atilla the Pun on May 02, 2002 at 10:46 PM.]

Man, this is a sweet unit for $150. I can not believe everything that it does. Oh, it's got it's shortcomings but for this price they aren't gamestoppers. AtP

Man, this is a sweet unit for $150. I can not believe everything that it does. Oh, it's got it's shortcomings but for this price they aren't gamestoppers. AtP

One with a quad-helix antenna for starters. Even that might not be good enough. You might want to look at units with external antenna connectors, like the new Garmin 76S or the Garmin V. Of course that's up an order of magnitude in cost.... I'm thinking $400 or more. OTOH, I've had very good reception with my Map 300X as compared to my friend's eTrex Vista. AtP

Ok, I just got to work after purchasing my new Map 330X at Sam's. This is a really good deal, the GPS, windshield mount, DC power and PC cables, and MapSend Streets all for $200 US. And tomorrow is the last day to buy the GPS if you want the $50 mail-in rebate from Magellan. Anyway, now that I've got the propaganda out of my system... I've got a question. My 330X shows firmware of 2.10 and North America map version of 1.10. Being a computer guy I thought I'd check Magellan's Web site for updates. Their site has 2.08 and 1.07 as the latest revisions. Is it typical for the Web site to be that far behind? Or am I looking at something wrong? Thanks, AtP

quote:Originally posted by GOT GPS?: Dont know why the Rinos have not been approved yet by the FCC, but I would like to get a pair of them. My guess (and it is pure speculation) is that they're not approved yet because they broadcast data. The GMRS band is approved for voice only, so there will have to be a wavier for this use. quote:Here is the GMRS website: http://www.g-m-r-s.org/ Uh, that is not an official site of any sort. It is run (I believe) by Robert K. Leef, who both sells radio equipment and is extremely knowlegable about radios and FCC regs. He has several good links regarding GMRS off his business site http://www.rkleef.com/ . It is intended to be (primarily) a (US) nationwide registery of GMRS repeaters so that travellers can contact repeater operators along their proposed path and request permission to use their repeaters. Or so new licensees can contact repeater operators in their local area and make arrangements to use the repeater. Respectfully, AtP

quote:Originally posted by GOT GPS?: Dont know why the Rinos have not been approved yet by the FCC, but I would like to get a pair of them. My guess (and it is pure speculation) is that they're not approved yet because they broadcast data. The GMRS band is approved for voice only, so there will have to be a wavier for this use. quote:Here is the GMRS website: http://www.g-m-r-s.org/ Uh, that is not an official site of any sort. It is run (I believe) by Robert K. Leef, who both sells radio equipment and is extremely knowlegable about radios and FCC regs. He has several good links regarding GMRS off his business site http://www.rkleef.com/ . It is intended to be (primarily) a (US) nationwide registery of GMRS repeaters so that travellers can contact repeater operators along their proposed path and request permission to use their repeaters. Or so new licensees can contact repeater operators in their local area and make arrangements to use the repeater. Respectfully, AtP