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Surveyor's Bearings Compared To Gps

always lost
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I have a question which I can't seem to find an answer to. I have a survey map that says the bearings are"astronomic, derived from solar observations and refered to the meridan through the southeast of the lot" it gives the bearings as


N 69 degrees 05' 50" E (meas) 1360.77' (psr)-547)


any idea how this can be converted to something that a GPS could use to find this spot? Or is this not even a spot? This bearing isn't given for a corner but for one length of the lot. What I am trying to do is find the four corners of the lot.

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Hi always lost. I am very interested to hear what kind of response you get from the knowledgeable Benchmarkers on this forum. Let me add what I THINK I know to further stimulate the dialog. My interest in GPS started with a 60 acre Site Plan with exactly that type of information (N69 deg 05' 50" E @ 1360.77'). Total Greek to me then. I bought a GPS and researched LAT and LONG on the internet. I visited a local Benchmark to "verify" the accuracy of my new toy (seemed to be darn good). I found Geocaching from a Benchmark link.


The Site Plan was in AutoCAD. I determined as close as possible the LAT/LONG grid to overlay on the Site Plan. Used my GPS to verify and add detail. Crude, but it worked for me. Found out I could enter "Surveyors" angles into AutoCAD. Based on that I think I know that your angle is 69.09722222 degrees clockwise of your North reference. That would be 20.9027778 degrees counter clockwise of your East reference. All such angles I have ever seen either have the North or South prefix. They then have either an East or West suffix. Look toward your prefix reference. Rotate toward the suffix direction by the number of degrees indicated. Then walk in that direction the number of feet indicated. X should mark the spot. If any of this is wrong, someone will correct it and we will both be smarter.


Now about your astronomic bearings. What is the North reference you want to use. Good question. In my case, I wanted to orient my Site Plan with TRUE North. It seemed to be over 10 degrees off. Found this site:Estimated Value Of Magnetic Declination I corrected for the LOCAL Magnetic Declination in Southeast PA at the time the original drawing was done. Again the results seemed to "fit". Are astronomic bearings TRUE, MAGNETIC, or something else?


Now the last part. How do you use this with a GPS. My answer is: Not as easy as it should be. I own a Garmin GPS Map 76S. Only unit I have ANY experience with. This would seem to be the perfect use for the Project Waypoint feature. But you can only enter a distance to an accuracy of 1/100th of a Mile (52.8') and you can only enter integer degrees. What good is that? So unless someone convinces Garmin to rewrite their software, you can do your own rough calculation to determine the next Waypoint (property corner), or there are sites on the Internet with calculators for this type of data.


I hope you find some of this usefull as we both await further comment.

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It would be so much easier to just use a tape and compass. This could be done in minutes, trying to do this with GPS could take you days as you do not have the precise GPS equipment to accomplish this.


Does your GPS have the ability to determine a bearing by pointing it in any direction? That would give you an idea of where to go but the distance will have to be measured. I don't see any easy was to do what you want.


To do this you would need to occupy at least 2 knows point with GPS to get lat and lon. Then calculate the positions of the other points you want to find and then go looking for them. But unless you have RTK, you will not get close enough.



It will help if you are proficient in math, e.g geometry and trig.. If not, compass and tape are you best tools.

Edited by elcamino
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For bearing's, azimuths and distances, I have been using the TrackMaker



You have the ablities to change all the formats,dms,ddd,utm,and the distances from meters,kilometers,feet,miles,ect.

You also have the ablity to export this data once created from the original data sheets or surveys into your gps.

It is awesome to predetermine,as close as possible the points before you go out.


I have been recently doing it and it is much more precise than some believe our handhelds can do.

Play with it is the best thing I can suggest,it's worth it to me.

I am also able to keep all track logs while searching and dowload them as well.

I have also started providing this image on each Triangulation Station I recover.

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N 69 degrees 05' 50" E (meas) 1360.77' (psr)-547)


You are seeing the "call" of a line. In this case, look NORTH and come toward EAST by the degress, minutes and seconds indicated. 1360.77 is the distance along the line.


If it were S xx degress E, you would begin at SOUTH and come toward EAST the specified number of degrees.


No, I can't tell you WHY they do it this way. It's a surveyor thing... [grin]



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Well first off, if in fact the survey was related to astronomic observations the bearing in that area will be virtually identical to GPS or 'geodetic' bearings. This is not to be confused with UTM grid bearings.


Geodetic bearings between points can be confusing. But at a given point an astronomic bearing and a geodetic bearing are very very close. The difference is related to the deflection of gravity from normal to the modeled ellipsoid at that point. Generally this is well under 8 seconds with rare exceptions.


- jlw

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OK. We are getting some interesting discussion, but we are NOT answering the question. The question as I see it is: You have a 4 sided, 4 corner lot with an Iron Pin in each corner of the lot. Using a GPS how do I find ALL the Pins?


STEP 1> You must have a property description with all 4 "calls" of the lines as Paul described them. You provided one "call" in your question: N 69 Deg. 05' 50" E

That is NORTH 69 Degrees, 5 Minutes, 50 Seconds EAST. Part of the call will also be the length of each line. This line is 1360.77 Feet long.


STEP 2> You must find one of the pins just by searching the area. A general idea of the property outlines, and a metal detector could be a big help here.


STEP 3> You need to calculate the PROJECTED WAYPOINT to another pin. You will need to convert the Angle of the line from Degrees, Minutes , and Seconds to Decimal Degrees. Because the WAYPOINT PROJECTION feature on my GPS is so poorly implemented, I will assume it sucks on all of them. So here is a link to A GREAT CIRCLE CALCULATOR on the web:


Compute Lat/Lon given radial and distance from a known point


Drop down the page to the second set of boxes. Make sure to set the Distance Units to Feet. And make sure the Earth Model is set the same as your GPS (probably WGS84). It will give you space to enter the LAT and LONG of the one pin you found. It gives you space to enter the line length into the Distance 1-2 box. It wants the line angle in the Course 1-2 box. Entering an angle of 0 Degrees (zero) would project you directly North. A 90 Degree entry would point you East. 180 Degrees is South, and 270 Degrees is West.


In this case:


50 / 60 = .83333


5+.83333 = 5.83333


5.83333 / 60 = .09722


69 + .09722 = 69.09722 Degrees


Again as Paul and I both said: Because the first letter of this line is N, you must think to look North and rotate 69.09722 Degrees Clockwise (toward the letter E, or East). So North = 0 Degrees. Rotate Clockwise ADDS. 0 + 60.09722 = 69.0722 So you just enter 69.09722


That is fine if you found the Pin at the SOUTHERN most end of this line. What if you found the Pin at the NORTHERN most end of the line instead. Looking at the line from this different point of view would change the "call" of the line to S 69 Degrees 5' 50" W. Think: look SOUTH. Rotate 69.09722 Degrees Clockwise toward the WEST. South = 180 Degrees. Rotate Clockwise ADDS. 180 + 69.09722 = 249.09722 which you would enter into the Course 1-2 box.


Click on the Compute Button to calculate the Lat 2 and Lon 2 which is the PROJECTED WAYPOINT to enter into the GPS as a Waypoint. You can look for the Pin right away, or just enter the newly computed Waypoint as your new Lat1 and Lon1 and calculate the next projection to the end of another line. Continue till you are done.


If this is too confusing. Find one Pin. Mark the cords. Note if it is in the NE, NW, SE, or SW corner. Post this information along with the "calls" of the North, Soulh, East and West lines. And I will calculate where you should look for the other 3 Pins.



Edited by Cardinal Red
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Thanks gentleman especially Cardinal Red for pointing me to the web site. You nailed the question right on the head. I have the survey map and have the other co-ordinates and know that the lot is rectangular. I even know where one of the stakes are. The lot is in the woods and according to the survey map the corners are marked with wooden stakes. These stakes have been in the ground for maybe fifty years so I'm not expecting to find much of them left. My goal is to locate them and get a reading so that I have it for future generations. Given that it is in the woods the GPS may not work that well but I won't know until I try. I also am trying to locate the points using the UTM grid. Between a compass, tape measure, GPS a can of OFF and some luck I may be able to do it. It's up in Canada so I won't be able to get there until vacation time. Again thanks!

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I really am interested to hear how you make out with this. Notice I edited the message I wrote last night to correct some directional references.


You wrote "GPS can be OFF". Well certainly we all know there is some error associated with our GPS Technology. But, consider this. Error is always discussed in term of deviation from absolute accuracy. Have you ever considered the accuracy of the relative position of multiple points. Say the accuracy of the cords of the one known corner are off by 20 Feet. Fine. You calculate waypoints for the other 3 corners. You locate them while you still have the same satellite cluster in the sky. Won't they all be off by almost exactly the same 20 Feet? Won't the actual relative position accuracy of the 3 FOUND property corners compared to the 1 KNOWN corner be MUCH more accurate than 20 Feet?


You say the lot is in the woods. Pick a time of year when the foliage is at a minimum, to maximize GPS reception. GOOD LUCK!



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Have you ever considered the accuracy of the relative position of multiple points. Say the accuracy of the cords of the one known corner are off by 20 Feet. Fine. You calculate waypoints for the other 3 corners. You locate them while you still have the same satellite cluster in the sky. Won't they all be off by almost exactly the same 20 Feet? Won't the actual relative position accuracy of the 3 FOUND property corners compared to the 1 KNOWN corner be MUCH more accurate than 20 Feet?

From what I've read, you might expect the relative positions to be accurate to a meter or two if the readings were taken within a few minutes. The main sources of error should be obstructions and reflections, noise, and of course, the precision of the receiver's calculations.


Has anyone tried testing this? Taken readings at two positions a known distance apart?

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From what I've read, you might expect the relative positions to be accurate to a meter or two if the readings were taken within a few minutes.


After reading your post, it hit me that your estimate seems very reasonable.

We're talking Canada now, so 1/1000th of a minute of LONG is very nearly only ONE meter. Of course the same 1/1000th of a minute of LAT will be very nearly TWO meters anywhere.


I also never thought to point out that the GREAT CIRCLE CALCULATOR on the Internet will give Projections to the 1/10,000 of a minute. Obviously you are going to have to round off the result from 4 decimal places to 3 decimal places to enter it into your GPS as a waypoint. But you could remember about how much you had to round off (up or down), and nudge the final result back in that direction. Probably to nitpicky.

Edited by Cardinal Red
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If you are trying to get the ultimate resolution out of your unit and will be doing averaging on it, use the decimal degree option. I think most of the units offer the same options.


Degrees to 5 decimals is finer than minutes to 3 decimals, which is in turn finer than seconds to 1 decimal. I wish there was an option to get any of these with one more digit, even though that digit is very questionable without averaging.


As for property corners, whatever you do don't disturb the evidence on the ground. The best plan would be to hire a local surveyor to find your corners and re-mark them as needed. If there is a decaying stake out there, you could ruin his best evidence while digging around looking for it. A local professional would know what was used in the area and may have resources you don't know about, such as records of other surveys in the area and ties to objects (trees and stones?) that you don't know are significant.

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Hi Bill. Food for thought on preserving whatever is left of those old wooden property corners.


But setting the GPS to decimal degrees? I would not have thought to consider that possibility in 100 years. But I grabbed the calculator. and now realize that the resolution of decimal degrees to 5 places is nearly TWICE that of minutes to 3 decimal places. Thanks for the tip.

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That Trackmaker GEO*Trailblazer 1 mentioned goes to 13 decimal places.


And it with let you enter it into almost any GPS although you do not see them the decimals are there,try the opposite in that you take a reading(GPS) then download it through this trackmaker(decimals) it will give you the 13 decimal points.


Now you can also use this precision to add a track (a strait line) with an azimuth

N(69.2555555*)E and bearng(1337 feet,meters,miles,yards) to as many decimals.

From (P.O.B.) Point of beginning of the given survey,or coordinates.


You can then create a new waypoint(coordinates) at the 2nd point and then (a strait line) with an azimuth and bearing to point 3 ect and 4.Closing the rectangle or square or if 3 points used a triangle.


Is in not true that the 1st letter N or S orients the 0 of the 360 to the start

North or start South,the degrees and the closing for the same E W.

thus if you go N 0* or S 180* there is no W E if it is 0*.1 it would be E.

If 359 W ect..

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Wow I can't believe the knowledge base that is out there. You people really know your stuff. I was talking with someone yesterday about the stakes in the ground and they said that they saw another one of them about 10 years ago but can only vaguley remember where it was. They said it was cedar so should still be there. I also found that that I had the coordinates in my GPS for the one spot I found. They are as follow 45deg. 26.492N and 080deg. 02. 267w this is taken from the south west corner.


Along the west boundry line the survey map read N20 deg. 51' 40" length 3381.04,


Along the north line it reads N69 deg. 05' 50E length 1360.77


along the west boundry it reads N 20 deg. 0 4'w length 3384.50


and the difficult boundry (which ends at the lat and lon that I listed reads

N69 deg. 15' 30" E but here is where it gets difficult, there are three lengths. They don't seem to add up to the total however the total that is listed is 1361.16


I had thought about getting a surveyor but was quoted a price in the thousands to re survey it. If I can find the corners I'll put a pile of stones or something and in the future it shouldn't be any harder than trying to find a geocache.

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I had thought about getting a surveyor but was quoted a price in the thousands to re survey it.


This is an indication to me that is could be a difficult piece of land to survey. While you have a description that states the stakes mark the corners, how do you know the stakes you found are the original ones? Or that the the were set in the correct location to start with? Thats the questions a surveyor would be staking his license on to determine. All too many times what is planted in the ground is not the corner is purported to be, I have seen it many times over the years. Not saying anything of the sort about you property but these things pop up all the time. People think that because they have something in the ground that it is gospel. Anyone can layout a piece of land but that does not mean its in the correct location.


This reminds me of my cousin and her husband. Their inherited this lake front lot in 1990 from his deceased parents who lived their since the 1950's. They moved there and and were happily enjoying life. There were no other adjacent property owners with-in 1/4 mile. Then in the 1990's, lake property soared in price and the land was sold off next to them. In comes a surveyor to resurvey the area (hired by new land owners) and it turns out their property pins are off by some 10-20 ft. Their drive is now off their land and part of the garage they spend $20g building is not on their property. So thinking that since the land had been in the family for nearly 50 yrs, they were in the right. So they hired a lawyer and fought it. They lost, their corners were not set by a surveyor and all they had was a meets and bounds description. It came out in court from witness's that the person who owned this land since the 1920's never had a licensed surveyor determine any of the lots. Who set the pins was unknown. The current survey was found the be a legal subdivision of the land in question and his property fit where the meets and bounds description said is was. The pins on his lot were just not in the location they were supposed to be. No one knows how they came about being set where the were found and used by his family all these years but the court said they were wrong. Cost him about 20g in lawyer fees and survey for his land that concurred with the survey by the other surveyor. btw-Records showed his parents only paid $500 for this 10 acres back in the 1950's. Its appraised value at the time of the court case was in the high $300,000. Lot is 100 ft wide by 1320 ft deep more or less, 100 ft is along lake.


Don't get me wrong, I am not criticizing you but sharing the pitfalls some find themselves in by not hiring a surveyor and nailing down the land boundaries till something comes along, like a neighbor coming by and telling you to get off my land in 60 days or I am sueing you. .


Moral of my story? If the corners are not set or verified by a licensed surveyor, it means very little. So if you value this land and plan to build on it , you may be wise to consult a surveyor and get the boundaries legally monumented before you do anything. Want you spend today may well worth it down the road as property is never going to come down in price.

Edited by elcamino
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Is in not true that the 1st letter N or S orients the 0 of the 360 to the start

North or start South,the degrees and the closing for the same E W.

thus if you go N 0* or S 180* there is no W E if it is 0*.1 it would be E.

If 359 W ect..


I am not sure I understand what you said there. But, when I was telling always lost about North = 0, East = 90, South = 180, West = 270 That was only in reference to filling out the Degree information on the SPECIFIC Web Page I provided him a link to. So if you enter 225 as your angle on THAT Web Page it will project you on a true SW heading. I make no claims about actual surveyors conventional terminology, or functionality of any other software application. I could have made that clearer the first time.


I also can't speak with any authority as to how experts interpret the two directional references of a surveyors "call". But there are only 4 examples I have ever seen and they are:


N XX Deg XX' XX" E - Look North and rotate East the specified angle amount.


N XX Deg XX' XX" W - Look North and rotate West the specified angle amount.


S XX Deg XX' XX" E - Look South and rotate East the specified angle amount.


S XX Deg XX' XX" W - Look South and rotate West the specified angle amount.


So the original example of N 69 Deg 05' 50" E will be found 69.0972 degrees Clockwise of North. If you can expand on this further you have my attention.


Now always lost. Could you check the numbers you provided. You started in the SW corner and provided information in a Clockwise direction. So the second Western line reference is actually for the Easern line? Correct?


The first Western line reference does not have the directional suffix, but it MUST be W (the same as the second Western reference. Correct?).


The second Western reference (which is actualy the Eastern Line) is not clear to me after N 20 Deg. Is that 4' 0" W. Is it 0' 4" W. Or is it something else?


Now about your Southern line with 3 different lengths that do not seem to add up to the total. Is it possible that is actually 3 lines that are NOT straight across. Please provide the 3 actual lengths in question and any directional information that might be provided with any of them individually.

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Traditional common law provided a method for someone to obtain title to land through use. The common law rules for adverse possession have been codified under both federal and state statutes. A typical statute allows a person to get title to land from the actual owner simply by using the land, out in the open for all to see. For example, your neighbor built a fence on your land with the intention of taking the property, paid property taxes, and you knew about it but did nothing. If this continued for a period of time set by state law, your neighbor may be able to claim this property as his/her own. The theory is that, by not disputing your neighbor’s use of your property through a lawsuit, you, as the actual owner have abandoned your rights to the property. There are several elements needed for adverse possession to result in title:


The length of time required for adverse possession in title varies - it could be as short as a few years or could run for twenty years or more. Typically public entities must establish a longer period of possession than individuals. Some states have adopted a rule which requires the adverse possessor to pay taxes each year on the land.


The possession must be open for all to see.


The possession must be exclusive to him or her (e.g., the fence in the above example, a driveway, road, etc.)


The possession must be hostile to the actual owner of the land.


To gain title to land through adverse possession requires strict compliance with the law, but can have dramatic impact upon land ownership rights.


An encroachment could result in title to your property being transferred to an adverse possessor. Under these circumstances, you might have to bring a lawsuit for trespass in order to prevent your neighbor from getting title to your land through adverse possession.


If you own land, it is important that you do not "sleep on your rights" since you could lose ownership of the land.



His description was meets and bounds and was not platted land.


Acquiescence (consent) has no bearing on this case.


The land was not properly surveyed. The corners were not in the correct place.


Very hard to understand I realize, thats why surveyor have to be licensed to perfrom the work. Someone with just enough knowledge to be damgerous, can go out with a hand-help GPS for instance and plant some property corners. He may think he is doing it correctly but has no knowledge of many other considerations that have to be taken into account.


Free Advice's real estate information helps the public to understand their legal rights.

Edited by elcamino
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Metes and bounds=bearing and distance. A compass reading is an azimuth. To convert a bearing to an azimuth or vice versa- N69deg,05min,50secE is equal to the compass bearing of 69deg5mins50sec. You must first find any corner described in your deed or plat. Then and only then can you use a bearing and distance to find another corner. You can't just find any given point with or without a Gps. Once you find the first, you can project a waypoint to another based upon a bearing and distance. Surveyors use the bearing/quadrant system and Gps 's use azimuth. Many surveyors use coordinates based upon the state plane system or use a datum specifically tailored to the individual job. If your plat has NAD83 coordinates then you can change them over to UTM's to use with a Gps.

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Is there a way to post a picture of the survey? I don't see any attachment option.




Check your inbox for an E-mail containing my Toll-Free FAX number. Send a copy of the survey via FAX and I'll give you some input. If you already have it in digital form, simply reply to the E-mail with the survey as an attachment.


I'm a real estate professional who deals with such issues frequently. I'm willing to look over those lines that don't add up, and I can provide magnetic bearings that you can use in the field. (I'll use your GPS coordinates to determine the correction from True North.)


Perhaps a couple of our "real" surveyors will send you contact info, also. If we pool our knowledge, I'm confident we can change Always Lost to Never Lost But Sometimes Bewildered. :D


Best regards,


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Have you ever considered the accuracy of the relative position of multiple points. Say the accuracy of the cords of the one known corner are off by 20 Feet. Fine. You calculate waypoints for the other 3 corners. You locate them while you still have the same satellite cluster in the sky. Won't they all be off by almost exactly the same 20 Feet? Won't the actual relative position accuracy of the 3 FOUND property corners compared to the 1 KNOWN corner be MUCH more accurate than 20 Feet?

From what I've read, you might expect the relative positions to be accurate to a meter or two if the readings were taken within a few minutes. The main sources of error should be obstructions and reflections, noise, and of course, the precision of the receiver's calculations.


Has anyone tried testing this? Taken readings at two positions a known distance apart?

I did an experiment this afternoon. The road in front of my house has a short straight stretch, so I measured off the distance between two trees while marking GPS waypoints at both ends. I did the experiment once in each direction.


The measured distance was 371 feet using a Keson 4 foot circumference wheel. I measured once in each direction.


The first GPS readings were start =N40.99989, W74.64525, end=N41.00087, W74.64456 for a distance of 404.69 feet (computed using the online NGS Geodetic Tool Kit).


The second GPS readings were start=N41.00086, W74.64458, end=N40.99990, W74.64525, for a distance of 395.66 feet.


Note that 0.00001 degree latitude (at 41° north) is equal to 3.64 feet, and 0.00001 degree longitude (at 41° north) is equal to 2.76 feet. The two waypoints at each end differ by 3.64 feet and 6.61 feet, respectively. The elapsed time was 6 minutes altogether.


Clearly there was a systematic error of about 30 feet this afternoon. That was also the approximate uncertainty indicated by the GPS unit. It would be interesting to see if the same absolute error would occur if the points were separated by a larger distance.

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I have a few comments:


1. The whole excercise of finding the stakes should be kept firmly in mind as for fun. As elcamino warns, if your purpose is anything other than fun, you could be in for a difficulty.


2. Wooden stakes in the ground for 50 years are likely completely gone now. You found one of them? Was it one of the 50-year old wooden stakes, or just some stake?


3. The GPS units we use are basically toys. Their accuracy is about a 15 foot radius. Doing a lot of averaging of readings isn't going to improve this significantly. To get an idea of what is going on, imagine that you are measuring the landscape with a supergiant pencil that marks the landscape with a line that is 15 feet wide. Any point in the 15-foot line could be the right one, not just the center of the line.


4. I agree with elcamino that what you should be using is a tape. You can get a 300 foot tape for not a whole lot of money. Perhaps a tape in combination with your GPS and calculations with the radial-to-coordinates site that Cardinal Red posted would be good to get an approximate directon to do your taping. Even at 1,300 feet, the cumulative error of a tape measurement will be way more accurate than a GPS unit. Mark the second stake's approximate position you find with the GPS with a pole and then tape-measure towards that pole from the one stake you have.


5. Never be confused between the concepts of accuracy and precision. You could calculate with 20-decimal point PRECISION, but if your ACCURACY is plus-or-minus 15 feet, you're wasting your expectations with the extra decimal points. In other words, if you calculate a reading of 1,307.3452346262346 feet based on readings with an instrument that is plus-or-minus 15 feet, then none of the decimal points are useful at all, nor is the 7. After the digits 130, it's just noise, and even the 0 is a bit fuzzy. <_< Fortunately, the GPS designers already round their displays to a precision (number of decimal points) that fairly closely matches their inherent accuracy. :lol:


6. Holograph - the relative accuracy of 2 GPS locations is independent of the distance between them. Each one will be plus-or-minus 15 feet. In other words, if you have 2 GPS units an inch apart, a third one in Pakistan, the distance between any pair of them will be known to about 15 feet accuracy. (Of course, elevation differences of the 2 points, and the fact that you're measuring around a large part of a spheroid would make quoting a distance rather complicated! Not having my GPS at hand, I don't know what it says about the distance from here to Pakistan.)

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