Hunting  for  Benchmarks

I quit!  Due to burnout and other factors, my benchmark hunting activity came to a stop on November 1, 2003.  One of the problems is that I work during almost all the daylight hours during the week, and my weekends are occupied by other interests.  Also I realized that I was wearing out my car (which already has almost 225,000 miles) looking for more and more remote benchmarks out in the suburbs.  All this, coupled with endlessly having to explain myself to relatives, onlookers, property owners and overzealous security guards, has led me to the decision to pull the plug on this hobby.  That's it.  I'm giving it up. Background: In the hotter months of 2003, I undertook the hobby of benchmark hunting.  After enjoying it for a while, I tired of it quickly, but I have left this page on line for the benefit of those who still have not heard of this activity, and those who still enjoy it. Many people asked me what benchmark hunting is all about — usually while I was walking around in circles on a street corner, alternately looking at a data sheet and a GPS navigator, as I tried to find a metal marker buried under years of accumulated grass and dirt.  Benchmarks typically are small metal discs embedded in sidewalks or bridges.  Some qualify as triangulation stations.  They are used by surveyors as reference points; and their latitude, longitude, and altitude has been determined with great precision, in some cases several decades ago.  Many benchmark discs in the Dallas area are dated 1934, 1947, or 1986.  Apparently those were three good years for surveyors.  The newer style (1986 and later) consists of a metal rod, usually driven 20 feet or more into the ground, which is surrounded at the top by a protective cover and is flush with the ground. The position of a benchmark is determined with great accuracy, as previously stated, however there are some which have had their coordinates "adjusted" to more precise figures, apparently after someone has made GPS measurements at the site.  Benchmarks were used as reference points long before anyone imagined a satellite navigation system like GPS. The art and science of benchmark hunting is a mixture of GPS navigation, urban archaeology and digital photography.  Benchmarks are often covered with dirt and weeds and can be difficult to find.  It helps if the marker is accompanied by a "witness post", which is a warning sign usually posted about a foot from the mark, urging people to leave it alone.  (See illustration.)  Each benchmark also has a data sheet available, which gives a description of its location, but in many cases the descriptions are fifty years old, and some descriptions refer to buildings, airports or water towers which are long gone.  A hand-held GPS navigator is an essential tool for the serious benchmark hunter, since buildings and trees come and go but latitude and longitude are here to stay. Hobbyists who locate a benchmark usually take a picture of it and its surroundings and upload the pictures to the Geocaching web site.  Close-up pictures are great for proving that you were there, but overview pictures help the next hunter find the mark. Quite often it is possible to find exactly the right location only to find that the marker has been destroyed, but this information is very helpful to others, and is posted so other people don't waste time looking for a marker that is no longer there.  In any event, when a benchmark is located, it is left alone, aside from brushing off the dirt to get a better picture. Personally, I think finding water towers and church steeples is too easy, but I did not hesitate to use them to run up my score.  My final total of 172 benchmarks does not include 79 others for which I hunted, but was unable to locate, 20 places where I just visited the area and posted notes about the site, for one reason or another, and 12 marks which I have reported as destroyed.  (For example, I have been to five places where, in each case, there was supposed to have been a water tower, but it was obviously no longer there.  These I reported as "destroyed".) Once I went digging in a public park with a spoon, looking for the MIDLOTHIAN marker, which was three inches underground.  That was probably my most difficult "find." If you're interested, here is a list of the benchmarks I found. If you're really interested, here is the complete list of all the benchmarks I found, tried to find, or didn't find, and the ones about which I posted other information. If you look into the possibility of hunting for benchmarks in your area, you will find that some marks are listed in the government database but have been destroyed years ago by farm machinery, vandals, landscaping, or widening highways.  Some are exactly where they are supposed to be, but they're covered with dirt or weeds or tall grass, or they may have been painted over!  Others are in place but are accompanied by fire ants, stray dogs, poison ivy, heavy traffic or unfriendly neighbors.   For more information about benchmarks, see "What is a benchmark?" at the   Geocaching web site.  New:   Geocaching Turns Deadly.  Police say it looks like 64-year-old James Max Chamberlain fell off a small cliff at Eisenhauer Park in San Antonio.  Chamberlain went on the scavenger hunt Saturday morning [12/11/2004] using a hi-tech GPS system he had just bought. Even if you know where something is, you can't necessarily get to it.  Be careful out there! A word about photography near federal buildings: In the current political climate, with all the talk of terror alerts and homeland security, there are a lot of security guards at federal buildings who are rather touchy about allowing photography.  Recently (9/3/2003) I ran into one such security guard who intercepted me just as I had located a benchmark at the Fort Worth Federal Building.  He told me that "photography of all federal facilities is prohibited."  This was rather discouraging, because I thought there was a chance that he could have been correct in his rash assertion, and perhaps this was a feature of the new Patriot Act of which I was unaware.  So the next day (9/4/2003) I went back to Fort Worth and talked to the security people at the Federal Building, including one very cooperative FPS officer who explained that photography of public buildings is not prohibited, nor could it ever be, as long as the Constitution is still in effect.  I was told instead that photography at any federal building is permissible as long as (1) you talk to the building manager first, and explain what you're doing, and (2) you don't take pictures of the guards, cameras, barriers, or any other components of the building security system. Let's face it... if I were a spy or a terrorist, the security guards would never have known I was taking pictures. Read this discussion among a bunch of other photographers who have experienced the same treatment, just for taking pictures! See also The Photographer's Right - A Downloadable Flyer.  An explanation of your rights when stopped or confronted for photography. Legal Rights of Photographers:  A clear explanation of what is legal to shoot and publish. Notice: I'm sure this looks like so much fun, you'll be tempted to take up this hobby yourself.  Before you do, let me offer a few words of caution:  When hunting for benchmarks, you are advised to observe the limits of private property, government property, restricted access areas, unsafe inner city neighborhoods, highway traffic lanes, and other hazardous areas.  This activity may also expose you to other risks, including (for example) inclement weather, exertion beyond your physical fitness level, adverse terrain, overzealous security guards (as explained above), insect bites, snake bites, dog bites, or exposure to poison ivy.  You assume the entire risk as to your use of the information on this page or any other page on this web site.  In no way shall anyone connected with ae5d.com be liable for any direct, indirect, punitive or consequential damages arising out of, or in any way connected with the use of this website, especially this page, or use of the information contained herein.  Read my disclaimer carefully.  Any actions you take based on whatever you saw, or think you saw, on this site are entirely your own responsibility.  New!   I have put together a new page about the Camp Wisdom Triangulation Station,  located at 32° 40' 20.38" N., 96° 55' 50.06" W., at an altitude of 761 feet.  Special Feature:   In Search of ARL5:  My field trip to the Arlington CORS station!  Be sure to see the latest pictures on the update page, Return to ARL5. My search for Benchmark BN0594 at Longhorn Caverns, near Burnet, Texas. The City of Cedar Hill, Texas, has its own benchmarks.  For example, Cedar Hill Benchmark #2009 (shown below) is located at 32° 36' 19.24328" N., 96° 56' 42.39458" W., at an altitude of 667.536 feet, and appears to be a Berntsen Model C1 marker.  Photos of Cedar Hill Benchmark #2009:     When I took these pictures, Cedar Hill benchmark 2009 was in the middle of nowhere, just off a lonely road near some railroad tracks.  Right after these pictures were taken, a new neighborhood sprang up across the street! Now available:  Meades Ranch benchmark earrings!  Surely you've heard of Meades Ranch, Kansas, if you're a benchmark hunter.  The Meades Ranch benchmark (KG0640) is at — or very near — the geographic center of the forty-eight contiguous states. Benchmark hunting is a spin-off of a hobby called Geocaching, in which people use GPS navigators to find a cache of goodies at some spot and sign the guestbook.  (Here is a brief explanation.)  This is obviously a great way to sell GPS navigation gear; however, Geocaching is potentially a way to get into a lot of trouble.  In most cases, the "hidden treasure" is on private property, or in areas which are off limits to the public, or in places where law-abiding people do not ordinarily go.  In any event, if you remove anything from someone else's cache, like GeoCoins for example (see below), it is suspicious behavior at best, and technically it is petty theft.  And you're at the mercy of everyone else who has visited that site, since anyone could stash illegal drugs or explosives or anything else in a GeoCache, and if you're caught with it in your hands, it's yours!  All I'm saying is that if you undertake this hobby, be prepared to spend the day explaining yourself to "badge happy" police officers, many of whom are a little too eager to take a bite out of crime.*   Signing the log book at a Geocache.  It was only about 100° that day.   Travis says, "You pick the strangest hobbies."  He's right.   Some Geocaches contain GeoCoins or Travel Bugs. Various styles of Geocaching coins exist, [1]  [2]  [3]  [4]  [5]  or you could design your own!  Several companies make custom tokens and medallions.  [1]  [2]  Geocaching:  A GPS Receiver is a Radio Too!  There's an Amateur Radio angle to this rapidly growing activity. Related hobby:  The Degree Confluence Project:  The goal of the project is to visit each of the latitude and longitude integer degree intersections in the world, and to take pictures at each location.  So, for example, you might take your new hand-held GPS navigator out into the boonies and try to find exactly 30°N., 94°W.  (This spot is in a swamp southeast of Beaumont, and has only recently been photographed.  Maybe that's because there are probably at least three spiders per square foot in an area like that, not to mention the snakes.)  What fun! Benchmark Hunting Terminology  explained at Benchmark Hunting  dot com.  A very professional-looking web site dedicated to this hobby. Other benchmark hunting enthusiasts:  [1]  [2]  [3] Photos of Survey markers and Witness Posts. Make your own benchmarks.  The markers aren't very expensive. Geodetic mark recovery  Maintenance and preservation of these marks is of utmost importance to users of the net and to NGSD [the National Geodetic Survey Division], recognizing that many valuable geodetic marks are destroyed by construction, new roads, erosion, or for other causes. Back to the top of the page Other material related to geography, latitude/longitude, GPS applications, etc.: Convert street address to latitude & longitude Convert any point on a U.S. map to latitude & longitude TopoGrafix - Power Tools for your GPS! Samuel J. Wormley's Waypoints:  Numerous interesting links National Geodetic Survey NGS Datasheet Retrieval Page for benchmark data sheets. National Ocean Service MapFinder Place names database with numerous links. GPS Web Tools : Latitude-Longitude of US Cities. The Australian National Public Toilet Map. Computing Azimuth and Elevation Angles with Javascript, for proper alignment of a satellite dish. Russian navigating devices on sale.  Navigating devices using Russian [Glonass] satellites will appear in the shops this year as the first alternative to the widely used GPS network of the United States, officials said overnight. GPS helps cities catch goof-offs.  GPS tracking devices installed on government-issue vehicles are helping communities around the country reduce waste and abuse, in part by catching employees shopping, working out at the gym or otherwise loafing while on the clock.  The use of GPS has led to firings, stoking complaints from employees and unions that the devices are intrusive, Big Brother technology.  But city officials say that monitoring employees' movements has deterred abuses, saving the taxpayers money in gasoline and lost productivity. A homemade receiver for GPS and GLONASS satellites by Matjaz Vidmar, S53MV.  This ham operator in Slovenia (?) went to a lot of trouble to build this equipment, and to prepare the documentation.  He has also undertaken many other experiments with UHF equipment. GPS jamming incident in San Diego harbor in January 2007.  The U.S. Navy was conducting a scheduled communications jamming training exercise in the Port of San Diego.  Two Navy ships participated in the exercise for approximately two hours. … [Along with numerous other services, GPS was jammed] — unintentionally of course — and the jamming continued for approximately two hours. More information about GPS as a potential threat to privacy can be found here. GPS background material and GPS-related web sites: Joe Mehaffey and Jack Yeazel's GPS Information Website Sam Wormley's Global Positioning System (GPS) Resources  (Excellent web site!) David L. Wilson's GPS Accuracy Web Page GPS Nuts is a web site for GPS navigation enthusiasts. GPS Enthusiasts Web Ring - Evidently there are several such web sites. How GPS works GPS overview Definitions of GPS Terms Another GPS overview GIS File Library Map gallery GPS history and theory of operation Current GPS Satellite Data from the little-known National Imagery and Mapping Agency. WAAS performance Stanford University Testbed Master Station has something to do with WAAS. Discussion of Selective Availability NGS FAQ page Explains the difference between NAD27, NAD83 and WGS84. Notes on GPS, Geodetic Datums, and Grid/Lat-Lon Conversions Principles and Practice of GPS Surveying. To see the current GPS week, among other things, go here. GPS applications: GPS Technology and Cars. Rino 110:  A walkie-talkie with built-in GPS. Garmin GPS sensors and boards. Garmin GPS35PC TracPak, available here. Using GPS to get Time and Frequency Using a GPS receiver as a NIST traceable frequency reference US Coast Guard GPS page GPS news Trimble Thunderbolt is used in precisely locating cell phones using Time Differential Of Arrival. The 12 Channel Lassen IQ GPS Receiver with DGPS looks like fun ... and for only a few dollars more you can get the Evaluation Board. This isn't the news page, but here are a couple of news items with a GPS twist: Big Brother rides shotgun:  Rental-car company uses GPS to track customer, fines him $450 for speeding. Move over, GPS.  Galileo will be Europe's own global navigation satellite system, providing a highly accurate, guaranteed global positioning service under civilian control.  It will be inter-operable with GPS and GLONASS, the two other global satellite navigation systems.  Galileo will deliver real-time positioning accuracy down to the metre range, which is unprecedented for a publicly available system. Update: EU Considers Running Galileo GPS Project.  The European Union is to consider taking over the Galileo satellite system as it is faced with demands for more time and extra public funds from the project's private builders, officials said. European satellite launch challenges GPS.  The European Union launched its first Galileo navigation satellite on Wednesday [12/28/2005], moving to challenge the United States' Global Positioning System (GPS). … Galileo's accuracy in positioning is to be 3 feet or less, while GPS's precision is more than 15 feet.  EU officials also say Galileo would never be switched off for strategic reasons, which could sometimes be the case with GPS. Europe still keen on Japan joining Galileo GPS project.  In just four years, Europe will bring about a sea change in the world of car and man navigation, which has long depended on a single service source, the American global positioning system. EU's satellite project, Galileo, funded at last.  After hours of haggling, the European Union on Friday [11/30/2007] salvaged its highest profile investment project, agreeing to divert €2.4 billion of public money to bail out its struggling satellite navigation project, Galileo.  Designed to rival the American GPS system, Galileo has been beset by funding difficulties and hit by lengthy delays after a consortium that was supposed to get the satellite network off the ground failed to agree on financial terms. How GPS Is Killing Lighthouses:  The popularity of the satellite-based global positioning system has led to the closure of lighthouses along the German coast.  Many more may soon be extinguished.  But critics question whether the new system is reliable and safe enough to warrant the closure of these historical beacons of safety. Announcement of the end of GPS degradation through Selective Availability 5/1/2000. GPS Standard Positioning Service Performance Standard (PDF) Military GPS news:  U.S. Could Deny GPS to Taliban The Defense Department could take steps to limit the usefulness of GPS receivers in the hands of Taliban forces without affecting North American users. The Pentagon is probably jamming GPS in Afghanistan:  The U.S. Defense Department has probably been selectively jamming signals from the Global Positioning System (GPS) in Afghanistan since the start of the air campaign [October 2001], according to nonmilitary GPS experts. Rocket launched into space; carries satellite to guide weapons.  A rocket carrying a GPS satellite to better guide military weapons was launched into space Thursday.  The Delta 2 rocket lifted off from Cape Canaveral at 3:04 p.m. (2004 GMT) with the modernized NAVSTAR Global Positioning System Block 2R military navigation satellite aboard for the U.S. Air Force. … The satellite is expected to circle the Earth for up to a decade before becoming obsolete. [The article includes no mention of the price tag for ten years of service.] Editorial comment: Surfing the internet, you may find people who believe that GPS navigation is degraded or unusable in cities where there is a TV station on Channel 23 or Channel 66.  This is because Channel 23's third harmonic and Channel 66's second harmonic are in the neighborhood of the GPS downlink frequency.  Some tech writers seem to be especially concerned because the signals from digital TV stations have the same noise-like characteristics as the GPS signals.  I haven't been to such a location to check it out, but keep in mind that spurious and harmonic signals from DTV stations are supposed to be 110 dB below the power level of the station's primary output, and even at a station with a megawatt of average power, that would only leave a maximum of 10 microwatts of power in the GPS band.  That's not much power, but then again, the GPS signals are very weak, too. Don't rely too heavily on GPS -- or any computer system! GPS drivers led astray by the lights.  British motorists left frustrated when their expensive satellite navigation systems do not work now have a culprit to blame — the northern lights.  The aurora borealis, which produces colourful light displays in the sky above northern Europe, disrupts the satellite signals that satellite navigation devices rely on to pinpoint their location. Similarly ... Convoy rescued after GPS led them to Utah cliff.  A GPS device led a convoy of tourists astray, finally stranding them on the edge of a sheer cliff.  With little food or water, the group of 10 children and 16 adults from California had to spend a night in their cars deep inside the Grand Staircase-Escalante National Monument. Back to the top of the page Be sure to visit the No-Frills Technical Links Page. Or start at the Index page.

Document location http://ae5d.com/bench.html Updated August 8, 2008. Page design by Andrew K. Dart  ©2008