Jump to content

Search the Community

Showing results for 'defying gravity 노래방,김천밤의민족화려한밤【KaKaoTalk:Za32】카카오 톡 상담 깜짝'.

  • Search By Tags

    Type tags separated by commas.
  • Search By Author

Content Type


Forums

  • Geocaching HQ communications
    • Geocaching HQ communications
  • General geocaching discussions
    • How do I...?
    • General geocaching topics
    • Trackables
    • Geocache types and additional GPS-based gameplay
  • Adventure Lab® Discussions
    • Playing Adventures
    • Creating Adventures
  • Community
    • Geocaching Discussions by Country
  • Bug reports and feature discussions
    • Website
    • Official Geocaching® apps
    • Authorized Developer applications (API)
  • Geocaching and...
    • GPS technology and devices

Find results in...

Find results that contain...


Date Created

  • Start

    End


Last Updated

  • Start

    End


Filter by number of...

Joined

  • Start

    End


Group


Location

  1. Seems like it was a good event, and the CO is trying to re-activate them (I saw an Owner Maintenance log saying "activate" on several of the archived caches). But they don't seem to have understood the guidelines in several areas. I found the commercial aspect of GeoDay12: Milan Coffee Works sort of amusing, as it reads to me like an example that Groundspeak would put in the Knowledge Books to show what a commercial cache looks like. I can only assume either the text was changed post publication or the reviewer simply missed it. The text is below. Despite the private sector is underrepresented At Geocaching Day, these are three businesses that need to be mentioned. There’s something really good going here on County Street. Between Milan Coffee Works, the Mother Loaf, and Original Gravity Company. Residents are able to purchase handmade quality products. These three businesses are owner operated and offer phenomenal products. Milan Coffee Works roasts and brews its own coffee from raw coffee beans. The Mother Loaf bakery has the most amazing artisan breads around. Original Gravity is a destination for beer enthusiasts; all their brews are made in house and they offer a family friendly environment so everybody can enjoy. If you haven’t already tried products from these companies, we hope you will make a trip back soon.
  2. Should this virtual cache be archived. http://www.geocaching.com/seek/cache_details.aspx?ID=60705 Gravity Hill GCED21 Thank You for the input What is it ... Gravity Hill is a phenomenon. Cars roll uphill, water flows the wrong way ... it's a place where gravity has gone haywire. Why it happens, nobody knows for sure. A few speculate that it's nothing more than an optical illusion. Others are certain that there is a definite gravity warp in the earth that causes this strange occurrence. But, whatever the reason, you can tell your friends that you've made it to the often talked about, but seldom found, Gravity Hill. What to do when you get there? Stay calm ... keep cool. As you strain your ears to hear the laws of physics being shattered, put your car in neutral (after checking behind you for oncoming traffic, of course) and take your foot off the brake. Your car will roll, uphill. Some people like to take water or various other non-flammable, biodegradable liquids and pour them onto the road. The liquids will flow uphill. (Your car might lie to you, but pure water will not ... you will believe in the power of Gravity Hill!) See the hint for detailed driving instuctions. To receive credit for this cache email me the distance in feet between the spay painted beginning and end of gravity hill. +/- 15 feet [This message was edited by cache chasers on April 07, 2003 at 02:33 PM.]
  3. Bicknell, You said "What I don't understand is what impact this has on understanding the geoid and making maps and such. Sounds like something a geologist would be more interested than a surveyer." The impact is that Gravity distorts the shape of the earth. See The Earth, as you may know is not a perfect Sphere, it spins on it's axis and this centrifugal force distorts the Sphere into the shape of an Ellipsoid, and well, it doesn't stop there. This ellipsoid is further acted upon by the force of gravity, or distorted by gravity, so much so that we have found that the ellipsoid is not smooth, it is lumpy. This really goes beyond geology, and in fact it is part and parcel a determiner of geologic development. Further we have found that gravitational forces are not static, they change and is so doing the surface of the earth is constantly changing. To add, The NGS, Decades before the DOD and NASA came along, was studying Gravity, and their work was used by DOD and NASA to aid the studies they have. A lot of what is studied and when goes along with the era, and the mission of the agency at the time. DOD first started studying Geodesy for Space purposes in the late 50's around 1959. The USAF had Geodetic Squadrons for about 35 years... Missiles you see, need to know where their landing strip is... Oh, and how to get there from well, you know. How it matters to the Surveyor and the Map is that the map is supposed to be a replication or representation which defines the face of the Earth on a smaller scale, or what we should find and measure when we are at any given spot on a map. The Surveyor is the person who is responsible for taking the measurements. In the Chicken Egg theory, the Surveyor has a reference point, and in a way the map will try to represent it, but when they observe the point they may observe that the reference has changed. So not only does Gravity interest the Geologist, it interests the Surveyor and the Geodesist as well. It affects everything in what seems like a relative uniform way. When precisely measure it, it really isn't as uniform as we think. The way we find that the gravitational references affect things the most are in the vertical. The vertical changes can of course affect horizontal locations as well, but the grid we measure with is fixed, it doesn't move. he earth moves. Latitude and Longitude are more stable than the surface of the earth. When we compare movements of the earth as compared to the static measure of Latitudes and longitudes as well as Orthometric, Ellipsoidal and Geoidal heights, We quickly see that the Earth is always on the move and that very much matters to all the different scientists and observers involved. We study it to keep track of all the points on the Earth which we have assigned importance to, and, there are a lot of them. If I can help any further Please ask, and in the meantime, if you are interested in some of the science behind it, the NGS website has Many papers on Gravity and Geoidal work, and Google can hunt up more if you are interested. It really is more interesting and better reading than you might think. Rob
  4. I've no idea who Doc smith is, or what the Skylark series was. However the scenario sounds very much like an Isaac Asimov short story I read many years ago. I can't rememebr the exact plot but think it revolved around two scientists arguing over what would happen if you were playing pool and turned off gravity. To resolve the argument they invented an anti-gravity machine to test the theory. When they tried it the pool ball accelerated off killing one of the scientists. So that's my answer; gravity
  5. They wouldn't move with it since they are not physically connected. They are held in place by the force of Earth's gravity, so it's reasonable to assume that if the earth moves, the satellites move with it.... You are right they orbit because of the gravity. The catch is you have to move the gravity. If you rotate the planet an inch, did you move the pull of gravity? Now if you moved the earth an inch over to the left... But that doesn't have to move the location of the north pole. The tweak in the earths wobble does move the mass/gravity well/whaever you want to call it so the chanbe wobble if pronounced enough might cause a slight tweak to the satalites orbit. If the Pole moved an inch to the left, just hold your GPS an inch more to the left than you normally do. On the more serious side... Now I'm not rocket scientist, but the Eath is always moving. The Earth moves around the sun; the sun moves around our galaxy: the Galaxy is moving through the Universe. We are all travelling at thousands of miles a second. (Therefor you all deserve speeding tickets) The force of gravity on the satalites is constanly changing. For instance we pass by Jupiter or the moon and the tides change. These satalites maintain their orbits/speed/direction/altitude by self-correcting their path constantly. Just my 2 cents
  6. it all depends on those involved really. I've seen a CO host an event "under that tree" so that one person could shimmy up and pass the log around below. I've seen a CO volunteer to meet potential seekers AT the cache WITH equipment. I've also seen ominous warnings on the cache page that the only way to get your name on the log legally was to do the climb --- of course this isn't really enforceable at all as I've been both the climber/signer and person on ground. of course, I have been the CO in one instance and caught someone signing for another person who was clearly 500 miles away at the same time. most of my T5s are boat anyway as gravity has a greater effect on me, so I'm more apt to trade a puzzle solution for a tree climber.... to each their own. of the higher d/t combos, most seem to come by challenge caches at this point in the numbers, so at this point many of our stats are skewed to show us much more physically inclined than we really are.
  7. Some advice we posted last fall when we were brand new. 150 finds later I'm not changing a word. 1) Hard to believe, but here's one we never imagined until an experienced cacher told us after 2 attempts - 'Lift the nearby lamp post skirt'. So, lift the lamp post skirt, turn over the rock, look in the tree stump, tree notch, tug on the fence finial, see if the bark is loose on the fallen tree etc. 2) Try for some kid friendly caches with a big container who's hint is 'stump'. Funny how this got our confidence way up. 3) Try for some easy lamp post caches being mindful of #1. 4) Bring, borrow some kids. My 2 elementary age boys are in the right age for 'hide and seek'. (Kindergartener got two of our finds yesterday!) So, sometimes its best to think like a kid. 5) GPSr merely brings you to the scene, it does NOT solve the crime. You do! 6) For a harder find, we put something at 'initial GZ' and walk toward it from several other directions from 10-15 ft away leaving something at those points. These intersecting lines usually give a better sense of the 'true GZ'. Then do #7 7) Walk back 10-15 feet from the presumed GZ and scrutinze where would be a good hiding place. It may be 10 or more feet away! 8) Events with instructed caching for noobs are wonderful. Even better when the kids score a geocoin for attending! 9) If you have a smartphone too, download the appropriate geocaching.com app and consider using both the phone and the GPSr. We found our 1st cache with the smartphone. (usually not in my possession) Besides my Garmin, we also happen to have a Geomate 'for the kids'. (usually vice versa it seems) It or the smartphone often confirms GZ for us. Sometimes due to differing indications of GZ it reminds us to be more 'open minded' about where the cache might actually be. 10) Our most recent tidbit - Don't believe every log you read or picture you see. 'The cache is visible from the road' doesn't necessarily mean that it is actually 'visible from the road'. GZ was, but the cache sure wasn't. 11) Sometimes hints are 'hints', sometimes they are 'clever hints'. 12) Buy 'The Complete Idiot's Guide to Geocaching' and read it. We did and it helped! 13) Micros & nanos are often defying gravity due to magnets. 14) It won't help with the find, but may make the DNF more bearable - Learn what poison ivy & its friends look like. 'Be very wary of vines that are hairy'
  8. Here is the monumentation code list. Monumentation Code Definition A Aluminum marker other than a disk included elsewhere in table B Bolt C Cap of cap-and-bolt pair DA Astro pier disk DB Bench mark disk DD Survey disk (other agency) DE Traverse station disk DG Gravity station disk DH Horizontal control disk DJ Tidal station disk DK Gravity reference mark disk DM Magnetic station disk DO Disk not specified (see description) DP Base line pier disk DQ Calibration base line disk DR Reference mark disk DS Triangulation station disk DT Topographic station disk DU Boundary marker DV Vertical control disk DW NOS hydrographic survey disk DZ Azimuth mark disk E Earthenware pot F Flange-encased rod G Glass bottle H Drill hole I Metal rod J Earthenware jug K Clay tile pipe L Gravity plug M Ammo shell casing N Nail O Chiseled circle P Pipe cap Q Chiseled square R Rivet S Spike T Chiseled triangle U Concrete post (without other marks) V Stone monument W Unmonumented X Chiseled cross Y Drill hole in brick Z See description You need to look at the datasheet to see the marker code. You could substitute the code letter for the designation letter to score more points. John
  9. Mount Everest would be my guess since it's the furthest point from the center of the Earth and hence might have less gravity pulling you down. I'm with Res on this one... The force of gravity you feel at any point on the earth should be related to the distance (radius) you are from the centre of the earth (mass) and the amount of mass enclosed within that radius. Theoretically, if you could get to the exact center of the earth, you would experience zero gravity as the radius would now equal zero, but we're talking "on" earth... not "in" earth. So we increase the radius by 8km or so (~height of everest) above sea level, without adding an equal amount of mass (not much earth up here!) so the effect of gravity will be reduced... but probably not enough to be noticed due to the lack of oxygen! Atleast that's what I seem to remember from all those Physics classes when I wasn't blowing things up! TOMTEC I would also agree with you had I not read an article a few years ago. It basically said that the force of gravity is not universal but varies and the place with the most variation in favor of lightness was in a body of water just south of ________. For a answer I will except the name of the country its closest to.
  10. That's the same thing that Nira mentioned in post #9 and explains a lot of what I've noticed. The only other way that basalt can interfere with a compass is from a gravity induced impact. I love the gravity induced impact as a method of interference.
  11. There are a number of antipodean/reflection/gravity train puzzles, where the icon is as far away as the other side of the world. These all date from before the 2 mile limit was brought in.
  12. Some great advice already given. We're noobs too with less than 25 finds. Here are some thoughts - 1) Hard to believe, but here's one we never imagined until an experienced cacher told us after 2 attempts - 'Lift the nearby lamp post skirt'. So, lift the lamp post skirt, turn over the rock, look in the tree stump, tree notch, tug on the fence finial, see if the bark is loose on the fallen tree etc. 2) Try for some kid friendly caches with a big container who's hint is 'stump'. Funny how this got our confidence way up. 3) Try for some easy lamp post caches being mindful of #1. 4) Bring, borrow some kids. My 2 elementary age boys are in the right age for 'hide and seek'. (Kindergartener got two of our finds yesterday!) So, sometimes its best to think like a kid. 5) GPSr merely brings you to the scene, it does NOT solve the crime. You do! 6) For a harder find, we put something at 'initial GZ' and walk toward it from several other directions from 10-15 ft away leaving something at those points. These intersecting lines usually give a better sense of the 'true GZ'. Then do #7 7) Walk back 10-15 feet from the presumed GZ and scrutinze where would be a good hiding place. It may be 10 or more feet away! 8) Events with instructed caching for noobs are wonderful. Even better when the kids score a geocoin for attending! 9) If you have a smartphone too, download the appropriate geocaching.com app and consider using both the phone and the GPSr. We found our 1st cache with the smartphone. (usually not in my possession) Besides my Garmin, we also happen to have a Geomate 'for the kids'. (usually vice versa it seems) It or the smartphone often confirms GZ for us. Sometimes due to differing indications of GZ it reminds us to be more 'open minded' about where the cache might actually be. 10) Our most recent tidbit - Don't believe every log you read or picture you see. 'The cache is visible from the road' doesn't necessarily mean that it is actually 'visible from the road'. GZ was, but the cache sure wasn't. 11) Sometimes hints are 'hints', sometimes they are 'clever hints'. 12) Buy 'The Complete Idiot's Guide to Geocaching' and read it. We did and it helped! 13) Micros & nanos are often defying gravity due to magnets. 14) It won't help with the find, but may make the DNF more bearable - Learn what poison ivy & its friends look like. 'Be very wary of vines that are hairy'
  13. What is it ... Gravity Hill is a phenomenon. Cars roll uphill, water flows the wrong way ... it's a place where gravity has gone haywire. Why it happens, nobody knows for sure. A few speculate that it's nothing more than an optical illusion. Others are certain that there is a definite gravity warp in the earth that causes this strange occurrence. But, whatever the reason, you can tell your friends that you've made it to the often talked about, but seldom found, Gravity Hill. What to do when you get there? Stay calm ... keep cool. As you strain your ears to hear the laws of physics being shattered, put your car in neutral (after checking behind you for oncoming traffic, of course) and take your foot off the brake. Your car will roll, uphill. Some people like to take water or various other non-flammable, biodegradable liquids and pour them onto the road. The liquids will flow uphill. (Your car might lie to you, but pure water will not ... you will believe in the power of Gravity Hill!) See the hint for detailed driving instuctions. To receive credit for this cache email me the distance in feet between the spay painted beginning and end of gravity hill. +/- 15 feet
  14. Green Toad, Let me see If I can help... You said: "If I understand correctly, there are vertical stations and there are horizontal stations. My question deals with this dichotomy, why are vertical and horizontal stations separate? Why don't the surveyors determine both dimensions accurately when placing a benchmark/monument/disk/etc.? It seems odd to me, to be accurate one way, but not the other. Am I missing something?" First, Holograph addressed this really well... Horizontal control, Lat/Lon uses a different Methodology to derive than Vertical control. He covered this with you. But the history is interesting and I will only go back so far. Until 1992 we used a system of 26 tide stations which were mathematically averaged to determine mean sea level. This was the basis for Vertical control. As science became available to observe the earth in better ways we learned that too many things affect tides to rely upon the average of them to suffice as a reference standard. Gravity, Wind, and how much water IS in the ocean at any given time are factors. Then we found that Wind is weather, and that isn't static. and gravity, well, it isn't static either. In fact the gravity has more to do with what elevation is about than wind or water, so we tossed the old model. The New Orthometric model was accomplished by leveling. Well so was the old model, but we now use just one point in Quebec to base all the leveling off of. it is known as Father Point/Rimouski. Accomplishing this caused all the numbers to change towards more accuracy.. Today in the GPS era we have a reference ellipsoid that the GPS Satellites use as a base model for the surface of the earth it is a smooth ellipsoid that represents what is now considered mean sea level and has nothing to do with the sea. It is just an averaged earth surface to the ellipsoidal size of Earth. Then we have a Gravity reference called the Geoid. It is a reference of the gravity measured over all the areas of earth. It is sort of generally ellipsoidal too but it is lumpy and unequal It is high in the mountains and low in the valleys, even lower in the oceans... It is not the actual terrain but is is close. Finally there is the actual ground. When we measure this with GPS, the figuring considers ellipsoid height, Geoid Height and orthometric height, with Orthometric height being the actual dirt. The formula works like this: The relationship geoid height is the vertical distance from the ellipsoid to the geoid level surface. These heights obey a simple equation h = H + N It is a straightforward procedure to algebraically subtract an interpolated geoid height, N, from a GPS ellipsoidal height, h, to obtain an orthometric height, H: H = h - N . What I mean by interpolated is that the geoid height can be above or below the ellipsoid height. The actual surface, the orthometric height can go below the ellipsoid as well. The ellipsoid is a smooth sphere like non undulating surface, the Geoid is comparatively lumpy and both are existent in the same space. So interpolate is meaning to recognize the positive or negative comparison to the ellipsoid. Your GPS is going to measure your height above or below these references in order to tell you what the elevation is. Now for your horizontal work, the Latitude and Longitude are based on the ellipsoid and so you make the grid we use and impose it on that ellipsoid. It seems pretty simple, and that is what GPS does. But the earth is not a perfect ellipsoid so then what? Well In the first place we used optical surveys and triangulation to base relative physical locations marked on the ground. We used a different model for our ellipsoid then too. Science reared it's progressive head again and we tossed the old model, then we had to make all the positions we had before fit the new model because we had very good physical measurements with which we could compare just like in the vertical models. We went from a place where we considered a place in Kansas, called Meades Ranch as the center of all horizontal survey in North America, to using a model we considered the center of the Earth, or pretty close to it. GPS Simply Positions in the horizontal to a grid drawn on the ellipsoid in a basic way. the size and shape of the ellipsoid has a lot to do with where the positions actually are and the science behind the ellipsoid is quite involved too as you well might imagine. Taken all at once the GPS can formulaically get close to a three dimensional position. But, and I mean a Big But, when you get to the critical, highly accurate observations, we cannot take them all at once because we are applying Calculus to these to statistically accurize a network of observations and the vertical observations will skew the horizontal ones and visa versa. This is why some datum treat the Horizontal and the vertical separately. In the end if you fix a horizontally averaged location against all the others in the average and you lift one up and push another one down in the vertical plain, you will observe that the positioning in the horizontal plain will have been altered. The Mathematics just won't play, so we keep them separate. "Also, correct me if I'm wrong, because there are three dimensions. Is a vertical disc equivalent to elevation, while the horizontal is equivalent to latitude + longitude?" Yup. You got it! :-) Simple GPS is not enough to position these locations, GPS has to add the Formulas contained in a Datum to get the accurate positioning these stations represent. The Horizontal Datum for these discs is called NAD83, and for the vertical is NAVD88. Some discs are Vertical only Some are Horizontal only, some carry Data for both, but the Datum for either Horizontal or vertical is kept separate always. WGS84 does not apply to these monuments in any sense. Hope that Helps, Rob
  15. Elevation is tied to the geoid, and the geoid is defined to be the imaginary surface at which the force of gravity would be identical across the world -- very close to mean sea level (but not identical to it). In the olden days, there were several designated tidal stations that were used to measure sea level, and that height was carried into the interior by leveling. In modern times, there are extremely sensitive instruments that can measure gravity, and so the geoid is determined directly from gravity measurements to greater accuracy than leveling. Additional data on gravity is obtained from precise measurements of satellite positions. Once the gravity measurements are obtained, they are tied into the NGS database of benchmarks via a dataset called "GPS on Benchmarks" and a mathematical model of the geoid is created so the the variation between the geoid and sea level is a small as possible. As time goes on, more data is available and the model gets better and better. You see a reference to the model on the NGS datasheet when you see GEOID HEIGHT and the geoid model is GEOID03. It's kind of interesting to see which benchmarks were used as part of the dataset. You can get a list of those benchmarks (and learn more than you ever wished to know about geoids) by going to this NOAA web site
  16. Couldn't resist making this one posted after deadline to avoid accusations of buttering up the contest owner. Thanks for all the fun - great entries! The scientiffic age - late C17th to present the Scientist gains Liberty of Action after generations of terrifying ecclesiatical Oppression and Persecution[1] 1687 Theory of gravity removes last doubts about heliocentrism. Struck by a Pyallup Apple geocoin which had made its way, untrackably - so we'll never know how, into a badly repositioned cache overhead, Isaac Newton formulates his theory of gravity. Publishes Principia Mathematica without being burned at the stake for heresy. 4 June 1783 Theory of levity conquers gravity. After much experimentation with heavier than air geocoins, including paper cored with metal ( the elgecko) - Ettienne Montgolfier, the more sober of the pair, suggests to his brother Joseph, the flighty one, that they abandon the 'flat coin' stipulation and inflate taffeta geocoins with some of the 'hot air' from Joseph's legendary bad jokes, also called 'levity' or 'avroair'. [2] Thus the Montgolfier brother's successfully defy gravity and launch the first balloon racers. 1.http://www.worldwideschool.org/library/books/youth/history/TheStoryofMankind/chap58.html 2. http://en.wikipedia.org/wiki/Montgolfier_brothers
  17. They wouldn't move with it since they are not physically connected. They are held in place by the force of Earth's gravity, so it's reasonable to assume that if the earth moves, the satellites move with it.... You are right they orbit because of the gravity. The catch is you have to move the gravity. If you rotate the planet an inch, did you move the pull of gravity? Now if you moved the earth an inch over to the left... But that doesn't have to move the location of the north pole. The tweak in the earths wobble does move the mass/gravity well/whaever you want to call it so the chanbe wobble if pronounced enough might cause a slight tweak to the satalites orbit.
  18. Here is another web based option you can try: http://tbagodev.maps.arcgis.com/home/index.html There are maps by marker type (Benchmark, Triangulation Station, Gravity Station, Bolts, Etc.) or you can look at all marks types together. You can filter the maps by any of the attributes shown below in the popup, including the First Recovered Date using the slider bar at the bottom of the map.. You don't need to have an account to view the maps, but if you sign up for a free account you can customize the maps and save your filters with your personalized settings. The popup also has links to the NGS datasheet and the Geocaching page.. Give it a try and let me know what you think. Tom
  19. The way I read the current NGS data sheet, NGS probably has only one set of measurements for this mark. The superseded elevation is in NGVD29, the adjustment done shortly after 1929. The old measurement data for many bench marks plus that for some new marks were fitted in an adjustment with different assumptions/measurements for gravity around 1988 to get the NAVD88 datum elevations. This disk apparently didn't have enough data to suit them or some other problem so it was not actually fitted in the adjustment. Its updated elevation was computed using a generalized VERTCON model of lower accuracy to convert from NGVD29 to NAVD88. Also note the newer elevation estimate is higher than the old one, due to differences in the underlying model, so certainly those numbers do not reflect subsidence.
  20. The "Marker Type" will often tell you that you would be looking for a tower, belfry, cupola, stack, or something of that nature. Often it is identified in the description as to what the 'mark' is. The following list is from the Hippo List. Monumentation Category Monumentation Code Definition Not for Landmark Stations O, U A Aluminum marker other than a disk included elsewhere in table O, U B Bolt O, U C Cap of cap-and-bolt pair D DA Astro pier disk D DB Bench mark disk D, U DD Survey disk (other agency) D, U DE Traverse station disk D DG Gravity station disk D, U DH Horizontal control disk D DJ Tidal station disk D DK Gravity reference mark disk D DM Magnetic station disk D, U DO Disk not specified (see description) D DP Base line pier disk D DQ Calibration base line disk D, U DR Reference mark disk D, U DS Triangulation station disk D DT Topographic station disk D DU Boundary marker D DV Vertical control disk D DW NOS hydrographic survey disk D, U DZ Azimuth mark disk O, U E Earthenware pot R F Flange-encased rod O, U G Glass bottle O, U H Drill hole R, U I Metal rod O, U J Earthenware jug O, U K Clay tile pipe O, U L Gravity plug O, U M Ammo shell casing O, U N Nail O, U O Chiseled circle O, U P Pipe cap O, U Q Chiseled square O, U R Rivet O, U S Spike O, U T Chiseled triangle O, U U Concrete post (without other marks) O, U V Stone monument O, U W Unmonumented O, U X Chiseled cross O, U Y Drill hole in brick O, U Z See description Landmarks not Listed L 0 Other mark or intersection station, see description Natural Objects L 01 Lone tree L 02 Conspicuous rock L 03 Mountain peak L 04 Rock pinnacle L 05 Rock awash Waterfront Landmarks and Visual Aids to Navigation L 11 Piling L 12 Dolphin L 13 Lighthouse L 14 Navigation light L 15 Range marker L 16 Daybeacon L 17 Flag tower L 18 Signal mast Aeronautical and Electronic Aids to Navigation L 21 Airport beacon L 22 Airway beacon L 23 VOR antenna L 24 REN antenna L 25 Radar antenna L 26 Spherical radome L 27 Radio range mast L 28 LORAN mast Broadcast and Communications Facilities L 41 Antenna mast L 42 Radio/TV mast L 43 Radio/TV tower L 44 Microwave mast L 45 Microwave tower Tanks and Towers L 51 Tank L 52 Standpipe tank L 53 Elevated tank L 54 Water tower L 55 Tower L 56 Skeleton tower L 57 Lookout tower L 58 Control tower Miscellaneous Landmarks L 61 Pole L 62 Flagpole L 63 Stack L 64 Silo L 65 Grain elevator L 66 Windmill L 67 Oil derrick L 68 Commercial sign L 69 Regulatory sign L 70 Monument L 71 Boundary monument L 72 Cairn L 73 Lookout house L 74 Large cross L 75 Belfry Features of a Building L 81 Gable L 82 Finial L 83 Flagstaff L 84 Lightning rod L 85 Chimney L 86 Cupola L 87 Dome L 88 Observatory dome L 89 Spire L 90 Church spire L 91 Church cross L 92 Antenna on roof L 93 Microwave antenna on building L 94 Rooftop ventilator L 95 Rooftop blockhouse Fairly easy to determine which are intersection stations. You missed out on that contest! You got points for the different marker types. John Edit: guess I'm a pretty fair fool.....
  21. Went out hunting today. Found 2 (easy) marks, missed 3. I would like to explain how I tried to find one of these marks, explain the problems I encountered, and hopefully get some good advice from the experts here. My only tools are as follows: Simple Boy Scout compass. 200 foot tape measure. Datasheet Here is the benchmark in question: JY1158 *********************************************************************** JY1158 DESIGNATION - K 34 JY1158 PID - JY1158 JY1158 STATE/COUNTY- OH/MADISON JY1158 USGS QUAD - VIENNA (1973) JY1158 JY1158 *CURRENT SURVEY CONTROL JY1158 ___________________________________________________________________ JY1158* NAD 83(1986)- 39 53 24. (N) 083 31 44. (W) SCALED JY1158* NAVD 88 - 345.156 (meters) 1132.40 (feet) ADJUSTED JY1158 ___________________________________________________________________ JY1158 GEOID HEIGHT- -32.86 (meters) GEOID99 JY1158 DYNAMIC HT - 344.968 (meters) 1131.78 (feet) COMP JY1158 MODELED GRAV- 980,071.6 (mgal) NAVD 88 JY1158 JY1158 VERT ORDER - SECOND CLASS 0 JY1158 JY1158.The horizontal coordinates were scaled from a topographic map and have JY1158.an estimated accuracy of +/- 6 seconds. JY1158 JY1158.The orthometric height was determined by differential leveling JY1158.and adjusted by the National Geodetic Survey in June 1991. JY1158 JY1158.The geoid height was determined by GEOID99. JY1158 JY1158.The dynamic height is computed by dividing the NAVD 88 JY1158.geopotential number by the normal gravity value computed on the JY1158.Geodetic Reference System of 1980 (GRS 80) ellipsoid at 45 JY1158.degrees latitude (g = 980.6199 gals.). JY1158 JY1158.The modeled gravity was interpolated from observed gravity values. JY1158 JY1158; North East Units Estimated Accuracy JY1158;SPC OH S - 210,320. 512,000. MT (+/- 180 meters Scaled) JY1158 JY1158 SUPERSEDED SURVEY CONTROL JY1158 JY1158 NGVD 29 - 345.329 (m) 1132.97 (f) ADJ UNCH 2 0 JY1158 JY1158.Superseded values are not recommended for survey control. JY1158.NGS no longer adjusts projects to the NAD 27 or NGVD 29 datums. JY1158.See file dsdata.txt to determine how the superseded data were derived. JY1158 JY1158_MARKER: DB = BENCH MARK DISK JY1158_SETTING: 7 = SET IN TOP OF CONCRETE MONUMENT JY1158_STAMPING: K 34 1934 JY1158_STABILITY: C = MAY HOLD, BUT OF TYPE COMMONLY SUBJECT TO JY1158+STABILITY: SURFACE MOTION JY1158 JY1158 HISTORY - Date Condition Recov. By JY1158 HISTORY - 1934 MONUMENTED CGS JY1158 HISTORY - 1957 GOOD NGS JY1158 JY1158 STATION DESCRIPTION JY1158 JY1158''DESCRIBED BY NATIONAL GEODETIC SURVEY 1957 JY1158''4.5 MI W FROM LONDON. JY1158''4.5 MILES WEST ALONG THE CLEVELAND, CINCINNATI, CHICAGO AND ST. JY1158''LOUIS RAILWAY FROM THE STATION AT LONDON, MADISON COUNTY, 200 JY1158''YARDS WEST OF A SWITCH TOWER AT MYERS, OPPOSITE MILEPOST CLE JY1158''168, AT A GRAVEL-ROAD CROSSING, 50 FEET EAST OF THE CENTERLINE OF JY1158''THE ROAD, 32.6 FEET SOUTH OF THE SOUTH RAIL, 1.5 FEET NORTH OF THE JY1158''WIRE FENCE, AND ABOUT 3 FEET LOWER THAN THE TRACK. A STANDARD DISK JY1158''STAMPED K 34 1934 AND SET IN THE TOP OF A CONCRETE POST. I figured this post would be sticking above the ground, but I never found it. Here is how I approached the mark: 1. Drove to site. 2. Measured 50 feet from road East and placed some rocks on a railroad tie to mark that position. As stated below this is where I started having problems. I actually measured 50 feed from center line and down the railroad tracks which did not run exactly W/E. -Here is where I had my first problem. Neither the railroad, nor the road run exactly N/S or W/E. I used my old boy scout compass as best I could, but found it really hard to site exactly east. Also I did not have my local declination which is apparently 6 degrees 22 minutes W changing at 3 minutes a year. Any good pointers on what tools/how to site East better. I'm supposed to site to true north right? 3. Now I measured 32.6 feel south of the south rail. Again I had the same problems as before figuring out what was exactly south. After this I felt I was "close", but I didn't see a mark yet. Interesting to note here: the line the old fence used to run appeared to be about 10 feet away from the point I was at instead of 1.5 feet away, so I figure I must have been within a 15 foot radius of where the mark should be. - I think a 15 foot radius of where the mark should be is pretty bad. Any pointers on how to get much closer? 4. I started kicking down brush trying to fin the mark. Also when I measured I was measuring from the railroad south I was measuring downhill, but a true 32.6 feet across a horizontal plane would actually put me further than my tape said, so i should have accounted for that right? How do I do that, basic trigonometry I guess? If I can get the angle that is. Also and additional question: The sheet said the mark was about 3 feet below the tracks, so I expected it to be above ground. Is there a good way to figure out where in the air "3 feet below the tracks" is? After my failed attempt I went to the government web site for a updated sheet and noticed a "mark not found" entry was made in 2006. Also there was a larger electrical/cable box in the area, and the local land owner told me that the railroad clears the area of any growth about every 4 to 5 years, so it is possible the cable company or railroad destroyed the mark at some point. Fire away with comments. You won't hurt my feelings. And thanks in advance for helping me to get on the right track here.
  22. I don't fall while geocaching either, but sometimes gravity overwhelms me. One time a mountainous path rejected me and I got to fly, briefly, but then gravity got aholt of me - that one cost me a Palm Tungsten C. Pine straw rejected my uphill advances once... yep, that dang gravity got me, and it cost me a nice compass. So, even though I don't ever fall, I don't carry fragile electronics in the woods either. You just never know when gravity will smack you in the face with the planet Earth! Ed
  23. The professional surveyors forum has an interesting post summarizing a recent conference at NGS. It helps understand where NGS is headed, and why bench marks, although still useful, will be less important after 2022. Basically, there will be no more updating of passive mark data sheet coordinates or elevations, as has been done in the past from NAD27 to NAD83(86) to various realizations up through NAD83(2011). The most accurate measurements will rely on GPS measurements and a gravity model derived by the GRAV-D program. It will take a while for various users to switch over, so they will still need the passive marks for a while. Look at the Corps of Engineers - many of their projects are still on NAD27. Some cities are still on NGVD29 elevations.
  24. Knowlege of the Earth's gravity field is a important part of the science of Geodesy and is vital to the ability to accurately determine height systems. Gravity stations were set as reference stations where the local gravity was observed with very specific equipment designed to observe the absolute value of the local acceleration of gravity, much like bench marks provide the local value of heights for other surveys. C&GS stopped setting these marks in the mid-60s. The collection of gravity data has been important to the ability to create a quality modern geoid model such as the recently released GEOID03.
  25. I am saddened to see the ending of what was to me the "best cache ever". These physical markers "on the ground" that tied the world together, making our maps more accurate and placed with such tremendous effort are very significant to me. No matter what the type, vertical or horizontal control points, gravity measurement points, border markers or historical places markers, they all mark an important essentially permanent spot on the earth where something is being or has been measured. I like to think of these things when I locate one. And best of all this cache was created and managed by a surveyor who has walked the walk and talked the talk. He posted only those survey monuments that fitted his vision and didn't violate geocaching rules such as private property locations. I want to thank outforthehunt for his efforts over the years, it was greatly appreciated by us. It seems strange that this cache (GC43F3) and its twin in Great Britain (GC45CC) which are essentially related directly to the real world of map making and exploration, a geocaching theme I believe, are to be terminated. Whereas endless and mindless matchstick containers placed along a road on a fence post for no other reason than they are 170 meters from the last one continue to litter the country side. Surely, there is room for both ends of the game, The lowest common denominator always results in a weaker product unfortunately.
×
×
  • Create New...