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Team CowboyPapa

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Everything posted by Team CowboyPapa

  1. I still use my PN-40 routinely. Consequently, I have kept in current with the latest FW 2.8. Nevertheless, I agree with Peoria Bill, you should really have the latest FW and the original out-of-the box CD to install on your PC to create maps, routes, waypoints, etc.
  2. How I calibrate to ambient pressure: 1. I have a Casio watch (Module No. 3415) which displays atmospheric pressure in increments of 0.05inHg, e.g., 29.90, 29.95, 30.00, etc. 2. This morning about 6 AM, PST, it read 30.40inHg. 3. Looking at the weather data for my local airport, SNA, I saw 1029.6mb (adjusted to SL), or 30.41inHg. 4. Airport, Weather Conditions For: Santa Ana, John Wayne Airport-Orange County Airport, CA. KSNA (NWS/FAA - SGX) Elev: 52 ft.; Lat/Lon: 33.68000/-117.86639 Current Time: Jan 28 10:03 am PST, is about 12 miles from my house (2' AMSL) with very quiescent, no wind conditions. http://www.wrh.noaa.gov/mesowest/getobext.php?wfo=sgx&sid=KSNA&num=72&raw=0 5. Consequently, I assume the SL adjusted pressure at the airport to be essentially identical to that at my location.
  3. So we went out to play tennis this morning with the court at 50' AMSL. Now, the standard air pressure at that altitude is 29.87 inHg. However, the actual air pressure was 30.35 inHg due to the weather effects. Notice that using that pressure to determine elevation would put us 430 feet below Mean Sea Level. Conclusion, one should not use a barometric device to determine elevation. https://www.digitaldutch.com/atmoscalc/tableatmosphere.htm
  4. Where is the legal limit defined? Is it a federal law? Is it a state law? Is it a county or city ordinance? Like if I walk my dogs in a city park without a leash, the ordinance prohibiting this is: 10-71-32. Huh, all laws have a number, what is the number here?
  5. Hey, what is this "legally" limit? If this is exceeded, can one be criminally charged or sued in a civil action?
  6. I would truly like to help; however, I am having trouble interpreting your title and text. Firstly, the title: the PN-30 is a GPS, consequently the implies that the PN-30 cannot to send to itself, a GPS? Also: 1. What are you trying to send? What type of information? Data? 2. What is the firmware version that you have installed on your PN-30? 3. Exactly what are you trying to download as an update? I have a PN-40 which for purposes of geocaching is the same as a PN-30 and I see none of these issues. Furthermore, I use Chrome and it does not impede my data management. I also suggest that when you can restate your problem, that you might also post it here: http://forum.delorme.com/index.php?/forum/60-earthmate-gps-pn-3040/
  7. That might be because nobody knows what conclusions you are drawing. Are you claiming that phones under a clear sky converge quickly to the correct coords? I can't tell. I agree, I'm not sure of neither what conclusions, or results, are attempted to be determined nor what the test objectives and requirements are. Consequently, I might suggest expressing them in the context of the information provided here: https://en.wikipedia.org/wiki/Design_of_experiments
  8. I will not take issue with that post above as it applies to the unit as it calculates its elevations along a trip. However, here is what I expect that it would do after it determines each elevation: 1. Subtract from each elevation after its determination the most recent elevation to calculate the most most recent elevation increment, either positive for ascent or negative for descent. 2. Then add algebraically that increment to the sum of the previous to determine net ascent (positive) or net descent (negative). 3. Also add all positive increments for total ascent and add all negative increments for total descent. 4. Alternatively, the subtraction of the first elevation from the last should yield the net ascent or descent. Note that I am avoiding the difference between calculating the intervals between all calculated elevations or just the recorded elevations.
  9. IM(not so)HO, the auto-calibration of barometric data by GPS derived data is like the old admonition: "..can't make a silk purse out of a sow's ear".
  10. Except.... We are talking elevation gain and loss. So if you include the spikes, it will show a lot more gain and loss than actually occurred. If you are just looking for actual elevation readings, what you state may work depending on the cause of the error. Want to look at some hypothetical numbers? OK, going up from actual elevation of 1,000 ft to 2,000 ft and taking GPS readings every 100 ft. GPS readings: 980, 1100, 1190, 1330, 1380, 1520, 1620, 1690, 1810, 1890, 2010 GPS intervals: 120, 90, 140, 50, 140, 100, 70, 120, 80, 120 GPS intervals summed: 120, 210, 350, 400, 540, 640, 710, 830, 910, 1030 Total error of 1000 feet: 30 feet Average error per interval: 3 ft
  11. DISCLAIMER: In a previous thread wherein determinations of elevation was discussed, my posts were characterized as "pseudo-scientific dribble": http://forums.Groundspeak.com/GC/index.php?showtopic=318508&view=findpost&p=5337463 Now, having presented that cautionary note, I will offer my opinion: 1. Regarding elevations calculated purely from GPS considerations, barometric data excluded, 2. I assume that the errors in successive elevation values will be normally distributed, http://en.wikipedia.org/wiki/Accuracy_and_precision 3. If so, I also assume that sum of a statistically significant number would approach zero as the number of values grows. Consequently, if you take readings every 10 seconds and subtract start and finish elevations of every 10 second interval for an hour, I would expect the sum of the errors for those 360 increments to be essentially zero.
  12. I have Topo NA 10.0 installed on both my W10 laptop and W7 desktop. I downloaded and installed the Topo10patch update from Delorme. https://support.delorme.com/kb/articles/43-geocaching-com-patch-for-topo-north-america-10 This allows Premium Members to logon to geocaching.com and having their active Pocket Query files downloaded to Topo 10 after selecting and clicking on Map Files, then Geocaching, Log In (first time only), finally Update. For those PQs with an associated child, waypoint file, Topo 10 will combine them into one file. Topo NA 10.0 may then be used to export these files in GPX format for installing in either a PN-40 or PN-60, both having the most recent firmware.
  13. The coordinate averaging subject reminds me of the previously discussed question of what is the basis of a GPSr's EPE value. All units display a value for each location; however, AFAIK, there has not been a provision of a unit's statistical definition of EPE value. For example, how may readings at that location would be within the displayed EPE? 50%? One standard deviation? Etc.? OTOH, a user can determine that relationship by coordinate averaging.
  14. Roger that regarding Excel and LibreOffice compatibility. My desktop OS is W7 which hosts MS Office 2003, while my laptop's W10 does not. Consequently, I store all my Excel and Word files in Dropbox. Then when working from my desktop, I am using MS Excel and MS; from laptop, working same files with LibreOffice.
  15. For definitions of precision and accuracy, I suggest this source: https://en.wikipedia.org/wiki/Accuracy_and_precision
  16. OK, I see an example of the input above. Now, how would the output that you desire appear?
  17. Counterclockwise according to the swirls in my morning coffee.
  18. I'm on the Newport Inglewood Fault, my front yard is going north while my backyard is going south. I have two GPSrs, front and back, to record this.
  19. I take care of the trees in my back yard; however, I spray 2-4-D on the weeds as the come up.
  20. Capt. Bob, at first glance, I agree with all but one consideration in your post. I can afford a second GPSr. However, my granddaughter reminded me that such a purchase would result in a decrement in her inheritance, so a side-by-side is off the table. Addressing the issue of determining accuracy without access to a known, good, acceptable, reference point, I have done this: 1. I have collected 40 data points, after waiting for sufficient stabilization, at my home (having reasonably open view of the sky). 2. Documenting the data on a spreadsheet and plotting them on an x-y (or NS-EW) plot, I see no strong directional bias (essentially, the number in each of the four quadrants is not all that unequal). 3. Consequently, I assess all the differences in location to be the result of random errors. 4. They do resemble a normal distribution in that the density of the points is higher at the center of the family of point and such density decrease with distance from the center. 5. Therefore, I conclude that in the absence of bias and the dominance of random effects that the center of the family is very representative of a bona fide reference point, if there was one. 6. I further conclude that the random errors are the result of conditions external to the GPSr. That is, the internal characteristics of the GPSr, do not propagate errors, neither biased nor random.
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