Kewaneh & Shark

It's most likely a temporary benchmark set for a construction project. It could also be a mark set for the City's benchmark network, but those are usually a bit more than a MAG Nail & washer. - Kewaneh

It looks to be a permanent instrument base for surveying purposes. The theodolites, total stations, and GPS equipment that surveyors use are attached to the tripods by a 5/8" screw on the top of the tripods. The screw on the base you found looks to be of the same size and thread depth. Often, in sites that require a lot of survey work where the same point is routinely occupied (like the type of work done in an open pit mine for example), a permanent base, with a known position & height, can be set up. Doing so saves the crew time by not having to set up the tripod, limits the possibility of setting up the instrument incorrectly, and reduces the possibility of blunders in the work, such as incorrectly measuring the instrument height. A tall permanent station such as this would be able to be seen from other similar stations around the mine to be used as a type of triangulation station, used for backsighting with a traditional instrument. - Kewaneh

OK. I'll bite... but I think we're getting of the OP's topic.... The key here is 'expert'. Judges are not experts in boundary; surveyors are. Any competent judge would weigh the testimony of a expert much higher than his or her own knowledge, or lack of knowledge, in any a subject. It's true, in some cases, that judges do what they please, whether or not it's correct or even legal - the higher courts help with that - but too many misjudgments is a quick way to lose a bench seat. Lawyers and judges are trained to understand how the Law works and functions as a whole. Surveyors are trained and do understand how to apply survey, boundary, and mapping laws to the best available evidence and existing field conditions. It could be argued here that most licensed surveyors are more knowledgeable and have more understanding of survey and boundary law than most lawyers and judges. (The exception being lawyers who practice boundary law.) Surveyors do occasionally have differing opinions resulting in boundary disputes, but they are very rare. In more than 15 years, I have only been involved in a boundary dispute that could have gone to arbitration and/or a judge once. (In that case, maps recorded at the County indicated that the dispute had been in existence since the 1930's. It probably existed prior to 1900. The argument was steming from a property corner placed in the 1870's.) As to 'fixing' a boundary: that depends on the definition of 'fix', and whether or not the problem is with 1) the true position of the boundary, or 2) the people on either side of the boundary. A surveyor does not have any authority to move a line, on a whim. (There are proceedures for moving a line and it does require the consent of all affected land owners.) A surveyor DOES have the authority and obligation to show a line in its true and correct position, whether or not either (or any) of the parties, or even a judge, agrees upon it. A surveyor may act as an arbitrator, but that is usually best left to a second surveyor. One distinction needs to be made: there are differences between lines of title, lines of ownership, and lines of occupation. Many people (including some lawyers) believe they are one in the same, and that's usually what they want 'fixed'. Most disputes that I've heard of involve occupation vs. ownership, or what a person believes they own versus what they really own. Simply put, a fence shows occupation, not ownership. A surveyor is obligated, by law, to show the true line of ownership. Whether or not either property owner agrees with that line is a different matter, and it's their prerogative to get another surveyor, or an attorney. (As a side note: California requires surveyors to research adjoiners properties along with subject properties to find and resolve any possible boundary disputes, and to make sure that no disputes are being created or perpetuated. This is not required in all States.) - Kewaneh

The differences between the two datums are often discussed in the benchmark forums. This thread titled 'Nad 83 - Wgs 84' was started in May of 2005 by DaveD. It has some good discussion about the subject. It should be said here that Dave is the Chief Geodetic Surveyor for the National Geodetic Survey and he had a large hand in the development of the NAD83 datum. This thread also has some good info. - Kewaneh

The difference between NAD83 and WGS84 is approximately one meter across North America. A bit more in some places, a bit less in others. For all intents and purposes, in the world of recreational GPSrs, the datums are virtually identical, as most recreational units only have +/-10 meter accuracy, +/-5 meters with WAAS activated. If your GPSr is set to NAD83 and you look for a cache with coordinates established in WGS84, your handheld will still get you within the targeted search radius. Unless you are using a survey-grade, sub-centimeter GPS system ($60,000+) the differences between NAD83 and WGS84 are next to irrelevant. The differences between the NAD27 & NAD83 are very subtantial. Differences of 200-400 feet are common. In some areas up to 700-800 feet, and possibly more. NAD27 does not play well with Geocaching. Hope this helps. - Kewaneh

Klipsch49er - Simply put: 'Recovered' = Found 'Not Found' = May be there, may be missing Here are a few other terms you may run across. Not a complete list, but a start. 'Good Condition' = Still usable for its original purpose or other applied survey purposes. 'Poor Condition' = May still be usable, but may require professional and/or NGS determination. 'Damaged' = Most likely not usable, but may require professional and/or NGS determination. Damage can often be repaired. 'Destroyed' = Definately destroyed. Requires NGS determination and usually some sort of proof (pictures or the physical disk). 'Scaled Coordinates' = The Latitude and Longitude coordinates are literally scaled from a map. These can be anywhere from a few feet to hundreds of feet off. 'Adjusted Coordinates' = The Lat/Long coordinates have been adjusted to be more accurate. These are usually within a few feet. 'Occupied' = Occupied with a survey-grade GPSr. Coordinates are usually sub-centimeter; much more accurate than your handheld GPSr. These are usually listed as Adjusted coordinates. Hope this helps. - Kewaneh

The magnetic locators used by surveyors are highly specialized and generally locate ferrous metals (ie steel & iron). The field produced is substantially different from a recreational treasure hunter metal detector in that the field on the survey models is a narrow beam and targeted, instead of being wide. Schonstedt is one brand of magnetic locator used by many surveyors. I've used one for years and found them to be bullet-proof. - Kewaneh

'Traffic Barrel' is not a survey term that I know of. The traffic barrels as shown by Renegade are called 'traffic delineators' and 'sand barrels' by Caltrans. The smaller delineators are portable. The larger sand barrels are permanent protective barriers. Like Renegade, these are what I think of when I hear the term. The term barrel is also used by Caltrans when describing a chute - particularly in a waterway or undercrossing under a roadway - as a way of channeling the water. It would seem that this is how the turn lane was being described. - Kewaneh

But seriously.... this is the worst I've found: HS1188 was covered when they lifted the tracks over an existing bridge. High res pics can be seen HERE. - Kewaneh

I think this is the key phrase in the announcement. I would agree with Artman that there won't be any outward sysem changes at this time. - Kewaneh

Welcome to the forums WBF PLS. I've seen one similar to that, but I was lucky enough to find it and scratch my head while I was there. GT1581 was placed on the top of a curb on a bridge. Later on, the county decided that a curb was not enough to to keep cars out of the canal and placed a concrete barricade on top of the curb. They managed to cover part of GT1581, but they left enough uncovered that it can still be used. - Kewaneh

I'll agree with that! Keep 'em coming Papa Bear. We don't have many like that over on this side of the continent, with the exception of some older PLSS marks. Thanks for letting us hunt vicariously through you. - Kewaneh

Here are four recent threads about handlebar mounts that may help answer your question. I'm partial to the RAM Mount, which has held my Magellan Meridian on the bars of my dual-sport BMW for many mails without trouble. Best ATV handlebar mount for Garmin 60csx ?, Any ideas? GPSr Advice?, A slightly different situation than most here... Garmin Handlebar Mount, Reviews/Thoughts? Are they sturdy? Another RAM mount question---Ezy-mount quick release, Looking to mount Garmin 60cx and use in multiple vehicles Hope this helps. - Kewaneh

I saw this one this past weekend on the Hunter Liggett military base, near Jolon, California. I thought it looked familiar. Link to Big Pic Link to Big Pic See a few more pics HERE. - Kewaneh

I mentioned an old California right-of-way marker in my earlier post (above). I was out this past weekend and drove by this one. There are not many left, except on the older stretches of two-lane. This one was in great condition. Link to Big Pic Link to Big Pic You can see a few more pics of it HERE. - Kewaneh

I've seen Tri-stations where there are arrows pointing from the station to the RMs, but this one seems to be a 'north arrow' of sorts. It's doubtful that there would be four RMs set 90 degrees from each other. It could also be the the carved arrow was done before the station was set. This is GU1092 in Madera, California. It had nails set in the concrete setting which pointed to the reference monuments. It's the only one I've seen like it. Link to Big Pic Link to Big Pic - Kewaneh

It's a groundwater test well. They are access points to the underground aquifer that allow water sample to be taken. Service stations usually have a few to monitor for possible leaks and contaminants, but they are found anywhere the groundwater needs to be checked occasionally. They can also indicate the depth of the aquifer relative to the surface. I worked for an environmental engineer for a while and I performed many level runs to carry the elevations from benchmarks to the tops of the wells so the engineers could monitor the water depth. - Kewaneh

That kind of precision doesn't exist, even for surveyors.... That precision DOES exist if the system is used correctly. Maybe not on a Leica. Certainly not on a single phase system. Especially not on any GIS system. I routinely use Topcon 5800 series and R8 dual phase, base-stationed systems and easily get precisions less than sub centimeter. When the measurements are checked with more traditional theodolites and laser/EDMs, the checks are commonly within 0.01 foot (3.048mm) for horizontal measurements. - Kewaneh, PLS

A forum search shows these threads that may answer some of your questions. Question about upcoming Bushnell ONIX 400CR Bushnell Onix 200, Free maps somehow? Bushnell Nav 500?, Quick review Bushnell ONIX GPS, Downloads, displays and georeferences satellite and aerial photography - Kewaneh

Modern property descriptions are written with their bearings relative to TRUE NORTH, not magnetic. Magnetic declination does change; true north is a constant. Past surveyors knew about variations in declination and compensated for it when they could, although it was not always possible. (When magnetic bearings were used, that fact was often noted in the description or on an accompanying plat.) Usually, the North Star (Polaris) or the sun was sighted to calculate a bearing on a line relative to True North to be used as a 'basis of bearing' for a survey. Bearings of a line are measured from the North or South, and then an angle turned to the East or West. A bearing of N36°43'46"E would be measured by facing North, then turning 36°43'46" to the East. Surveyors use bearings in four, 90 degree quadrants (NE, NW, SE, & SW). A bearing of a line more than 90 degrees is an azimuth bearing. Azimuth bearings are measured clockwise from North. If a GPSr is used to measure a bearing, the datum the unit is set to is irrelevant. Bearings and distances do not change with datum, as a datum determines the point of origin for a coordinate system, not a metes & bounds description. Renegade is correct that need to look at the whole property description to determine the locations of your property corners & boundaries. Trigonometry or coordinate geometry can be used to calculate those positions. Also, at least two common and known corners described (or implied) in the description must be located on the ground in order to correctly determine the locations of the remaining corners. Reading thru a property description to find ones property corners, or for the math exercise isn't a bad thing, but trying to determine boundaries with the intention of marking those boundaries - particularly if those boundaries are unclear or unmarked - may be illegal. It should be said here that a Professional Land Surveyor should be consulted to properly and correctly interpret any property description. - Kewaneh

Simply put, you can't put that into your GPSr. Those are not coordinates, but bearings of a line. Two lines actually. The first is a bearing of a particular line. The second indicates a radial bearing to the begining of a curve. As a general rule, property descriptions are written in a method called 'metes & bounds'. You begin a particular point and then the courses are described with a compass bearing and distance. Geodetic coordinates cannot be derived from them unless at least one point within the courses is related to a geodetic coordinate. This is rarely done, with exception to larger, and usually government surveys. - Kewaneh

NICE!!!!

This thread called 'GPSr Advice?, A slightly different situation than most here...' was started a few days ago. The OP has some of the same concerns you do, although a different machine. This is my post where I address different mounts and machine/GPSr vibrations. Hope this helps - Kewaneh

Check out RAM Mount. They can attach a GPSr (or just about anything) to just about anything. I've got one that's held my Magellan Meridian to the bars of my R100GS motorcycle for more than 20,000 miles without a problem. - Kewaneh

If you are planning on using the GPSr exclusively on your bike, I'd look at a few of the other Garmins such as the Quest, Zumo, or Street Pilot series units. They've been used on many offroad motorcycles with great results. If you plan on using the unit off the bike too, a Garmin 60CSX would be up to the task. I'm a Magellan fan, but I would suggest going with a Garmin because of the support, both by the company and by aftermarketers. No matter which unit or company you decide to go with, if you're going to be in any serious off-road courses (very technical or with high speeds) a Tourtech mount would be a better choice for a mount. A RAM mount is excellent (My Magellan Meridian is attached to my R100GS with a RAM) but as tough as they are, they are plastic. The Touratech mounts are aluminum, and they have vibration dampers and are lockable. One thing to consider as well, is hardwiring your GPSr to the bike's power supply. Every GPSr is susceptable to vibrations. Vibrations can cause the batteries to momentarily lose contact and occasionally crash the unit. I've had it happen a few times when my GPSr was on the bike using internal batteries, but never when when it's been hardwired. My Magellan has seen about 20,000-25,000 miles attached to the bars of my bike. A good place the check for GPS units and offroad motorcycle uses is in the Adventure Rider Forums. ADVRider.com is a site devoted to dual-sport & offroad motorcycles and they have a large sub-forum devoted to GPS units. They also trade tracks (in Garmin format). Hope this all helps. - Kewaneh