Author Topic: lat/long for dummies? please help  (Read 2146 times)

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Offline wipartimer

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lat/long for dummies? please help
« on: January 14, 2007, 04:29:41 PM »
Can anyone help me to understand how coordinate systems work? I admit that I'm totally lost. I recently bought some hunting land. The survey I got shows one corner at N 89 (degrees) 42'40"W  , N 00 (degrees) 34' 2" E. I borrowed my Dad's Vista Gps and it showed the exact same spot as 44 46' 16", 90 49'".  The spot is the same because it is on a county survey post on the corner of the property. the post is dated sept. 11, 1934.  What accounts for the different numbers. or how do all these location numbers work? Any Help would be greatly appreciated. Thanks
Mike



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Offline Siskiyou

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Re: lat/long for dummies? please help
« Reply #1 on: January 14, 2007, 07:16:47 PM »
Here is a link to a good resource on LAT/Long. http://www.maptools.com/UsingLatLon/Formats.html

Normally the default setting on Garmin gps units is HDDD° MM.MMM’.  What format and NAD is your father’s Vista set at?  This also the format normally found of Forest Service and BLM maps.

Frankly I am lost using the data you have provided.  There could be a lesson in this for me. 

Maybe SURVEYOR can help us out with this question.

Could the N referenced in your information be the North corner of the property?
There is a learning process to effectively using a gps.  Do not throw your compass and map away!

Boycott: San Francisco, L.A., Oakland, and City of Sacramento, CA.

Offline SURVEYOR

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Re: lat/long for dummies? please help
« Reply #2 on: January 15, 2007, 06:13:41 AM »
Well for one we know N 00 (degrees) 34' 2" E is wrong. That would be 34 minutes East of the Prime Meridian,

"The zero meridian (0°), used as a reference line from which longitude east and west is measured. It passes through Greenwich, England."



I used your Lat Lon as best as I could understand, and ploted the above. Are you even close?



Beyond that. The Info you gave is some what hard to follow. As far as the Survey, ??? I don't know with out seeing the plat.
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Offline SURVEYOR

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Re: lat/long for dummies? please help
« Reply #3 on: January 15, 2007, 06:34:29 AM »
Here one Siskiyou gave me a while back,

http://www.fs.fed.us/database/gps/gps2gis/gps_gis_v7-0.pdf

Thanks Siskiyou! A good read.
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Offline Siskiyou

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Re: lat/long for dummies? please help
« Reply #4 on: January 15, 2007, 09:16:36 AM »
I am going to break this into two items:

A recreational gps unit (Vista) is not of surveying quality.  I played with the data you provided off the Vista but because it was not in a standard format I would be guessing at the location.  If this data were provided in regards to an emergency call the dispatcher would be asking for more information. A dispatcher would work the information and if the end of the shift came, he would not sleep that night.

You have asked the right questions and I believe you are interested in learning to use your Dad’s gps.  If you can barrow it and the manual for sometime take advantage of the opportunity.  From the data you provided I believe the default settings have been changed.  If you get into the menu>setting you should be able to return it to the default settings.  I believe the information you need is on page 50 of the Manual.  If you cannot find the manual you can find it Garmin.com under support.

Part two is the survey you are referring to:

The survey notes are very important regarding the corner you located.  The notes should tell you the methods the surveyor used.  Different States have different standards for landline surveys.  Federal Agencies such as the FS or BLM follow the BLM standard, which dates back to early laws. Check out this resource

  http://www.blm.gov/az/cadastral/manual/manindex.htm

I was raised in an area that has a lot of land administered by the Forest Service and BLM.  Yellow survey tags are all over the country, and are referred to as “K” tags.  The “K” tag is broken down into 36-sections.  Each section is numbered and a nail will be placed in the tag showing the general legal location of the tag.  At the base of the tag you will find the Township, and Range scratched on the tag.  The maybe a note saying the corner is 15 chains at 60°.  “K” tags maybe off set from the corner (brass cap) to assist in finding the corner from a road. 

I do some searching for Bench Marks, and I recommend the reading at the following link.  You will find it good reading.  And by plugging in you local zip code you can get the Lat/Long of some local survey markers and use them as a learning tool.

 http://www.geocaching.com/mark/

A resource that I use at times is   http://www.topozone.com/viewmaps.asp

A recreational gps like a map is a tool.  But legal surveys are more precise.  A recreational gps should get you within grenade distance of a property line. 

A key to using a gps is that everybody in the loop must be using the same format and NAD.
I guess I would start the search around Rathbone Creek.  A guessing game?  Or would they find a body clutching a gps six months later?











There is a learning process to effectively using a gps.  Do not throw your compass and map away!

Boycott: San Francisco, L.A., Oakland, and City of Sacramento, CA.

Offline Siskiyou

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Re: lat/long for dummies? please help
« Reply #5 on: January 15, 2007, 12:02:35 PM »
I found the below link of interest if I had property in Wisconsin, or just general historical information.  Or for those who have had problems sleeping lately.

http://www.wsls.org/assessor.htm

Additional Information

http://www.legis.state.wi.us/statutes/Stat0236.pdf

(2) ALLOWABLE SYSTEMS. An approving authority under s.
236.10 may select any one of the following systems:
(a) The Wisconsin coordinate system of 1927, which is based
on the North American datum of 1927.
(b) The Wisconsin coordinate system of 1983 (1986), which
is based on the North American datum of 1983 (adjustment of
1986).
(c) The Wisconsin coordinate system of 1983 (1991), which
is based on the North American datum of 1983 (adjustment of
1991).
(d) A county coordinate system as approved by the department
of transportation or a coordinate system that is mathematically
relatable to a Wisconsin coordinate system.
(3) ZONES. Each of the systems under sub. (2) includes the following
zones:
(a) A north zone composed of the following counties: Ashland,
Bayfield, Burnett, Douglas, Florence, Forest, Iron, Oneida,
Price, Sawyer, Vilas and Washburn.
(b) A central zone composed of the following counties: Barron,
Brown, Buffalo, Chippewa, Clark, Door, Dunn, Eau Claire,
Jackson, Kewaunee, Langlade, Lincoln, Marathon, Marinette,
Menominee, Oconto, Outagamie, Pepin, Pierce, Polk, Portage,
Rusk, St. Croix, Shawano, Taylor, Trempealeau, Waupaca and
Wood.
(c) A south zone composed of the following counties: Adams,
Calumet, Columbia, Crawford, Dane, Dodge, Fond du Lac, Grant,
Green, Green Lake, Iowa, Jefferson, Juneau, Kenosha, La Crosse,
Lafayette, Manitowoc, Marquette, Milwaukee, Monroe, Ozaukee,
Racine, Richland, Rock, Sauk, Sheboygan, Vernon, Walworth,
Washington, Waukesha, Waushara and Winnebago.
(4) APPLICABLE DEFINITIONS AND SURVEY CONNECTIONS. (a)
The following definitions apply to the systems under sub. (2):
1. For the Wisconsin coordinate system of 1927, the definitions
provided by the national geodetic survey in U.S. coastal and
geodetic survey special publication 235 (1974 edition).
2. For the Wisconsin coordinate system of 1983 (1986) and
the Wisconsin coordinate system of 1983 (1991), the definitions
provided by the national geodetic survey in the national oceanic
and atmospheric administration manual national ocean service,
national geodetic survey 5 (1989 edition).
(b) Existing positions of the systems under sub. (2) that are
marked on the ground by monuments established in conformity
with standards adopted by the national geodetic survey for 3rd−
order work and above and the geodetic positions of which have
been rigidly adjusted on the North American datum of 1927, the
North American datum of 1983 (adjustment of 1986), the North
American datum of 1983 (adjustment of 1991) or any later adjustment
of the North American datum of 1983 may be used to establish
a survey connection to the systems under sub. (2).
(5) OVERLAPPING LAND. If portions of any tract of land that is
to be defined by one description in a plat are in different zones
under sub. (3), the positions of all of the points on its boundaries
may be referred to either of the zones but the zone to which those
positions are referred and the system under sub. (2) that is used
shall be named in the description and noted on the face of all maps
and plats of the land.
(6) COORDINATES. (a) The plane coordinates of a point that are
to be used to express the position or location of a point shall consist
of 2 distances that are expressed in U.S. survey feet or meters and

decimals of those feet or meters. The definitions of survey foot
and meter in letter circular 1071 July 1976 national institute of
standards and technology shall be used for conversion between
feet and meters.
(b) For the Wisconsin coordinate system of 1927, the distances
under par. (a) are the x−coordinate, which shall give the position
in an east−and−west direction, and the y−coordinate, which shall
give the position in a north−and−south direction.
(c) For the Wisconsin coordinate system of 1983 (1986) and
the Wisconsin coordinate system of 1983 (1991), the distances are
the northing, which shall give the position in a north−and−south
direction and the easting, which shall give the position in an east−
and−west direction.
(d) Coordinates in all of the systems under sub. (2) shall
depend upon and conform to the plane rectangular coordinate values
for the monumented points of the national geodetic reference
system horizontal control network that are published by the
national geodetic survey or by that agency’s successor if those values
have been computed on the basis of a system under sub. (2).
(7) USE OF TERM RESTRICTED. No person may use the term
“Wisconsin coordinate system” on any map, report of a survey or
other document unless the coordinates on the document are based
on a system under sub. (2).
(8) DESIGNATION. Any person who prepares a plat under this
section shall designate on that plat which of the systems under sub.
(2) and which of the zones under sub. (3) that person has referenced.
(9) MULTIPLE DESCRIPTIONS. If a document describes a tract of
land by means of the coordinates of a system under sub. (2) and
by means of a reference to a subdivision, line or corner of the U.S.
public land surveys, the description by means of coordinates supplements
and is subordinate to the other description.
(10) RIGHT OF LENDERS AND PURCHASERS. A lender or purchaser
may require a borrower or seller to provide the description
required under s. 236.20.
History: 1979 c. 248 ss. 10, 25 (1); 1993 a. 16, 490; 2001 a.

(b) A clear and concise description of the land surveyed,
divided, and mapped by government lot, recorded private claim,
quarter−quarter section, section, township, range, and county and
by metes and bounds commencing with a monument at a section
or quarter section corner of the quarter section that is not the center
of the section, or commencing with a monument at the end of a
boundary line of a recorded private claim or federal reservation in
which the subdivision is located. If the land is located in a
recorded subdivision or recorded addition thereto, the land shall
be described by the number or other description of the lot, block
or subdivision thereof, that has previously been tied to a corner
marked and established by the U.S. public land survey.

(b) Above clearly fits into the standard land survey description of quarter-quarter section, section, township, range and county. 





There is a learning process to effectively using a gps.  Do not throw your compass and map away!

Boycott: San Francisco, L.A., Oakland, and City of Sacramento, CA.

Offline wipartimer

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Re: lat/long for dummies? please help
« Reply #6 on: January 15, 2007, 04:23:07 PM »
wow, Thanks for all the info and replys! :) I havent got to read and absorb it all, thats what I'm gonna start doing, I just wanted to say thanks in advance.. I'll read all these links tonite, and borrow the gps (and instructions this time ;)) tomarrow nite. and see if I can make some sense of things. I just couldn't understand how a gps and a survey  could be so far apart.
Mike



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Offline Siskiyou

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Re: lat/long for dummies? please help
« Reply #7 on: January 15, 2007, 04:56:11 PM »
The key is that historically surveyors in pre-gps times used two or three methods to get the correct Lat/Long.  I believe this link discusses the methods http://www.blm.gov/az/cadastral/manual/manindex.htm The link was in an early post, and you may have looked at it already.   Standards for surveyors are stricter today then in yesteryears. In regards to the survey on your property everything most likely is correct, but without the plat and field notes you are in the blind.  I am sure that you can get a copy of these documents at the County Office.  And you may have received some at the time you purchased the property.

Frankly I included a lot of information to point out that it is not simple to the layman when it comes to surveys.

Make sure the gps is set on NAD 27 when comparing a survey or WGS 84 when using Garmin MapSource US Topo.  If you read all the legal stuff Wisconsin coordinate system of 1927 and NAD 27 appear to me the same thing. 

You can post additional questions or if need by send a PM and I will respond to the question.  I must admit the 00 sent up a red flag. 

You should be aware that gps locations and errors change during the day because of the position of satellites. 








There is a learning process to effectively using a gps.  Do not throw your compass and map away!

Boycott: San Francisco, L.A., Oakland, and City of Sacramento, CA.

Offline SURVEYOR

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Re: lat/long for dummies? please help
« Reply #8 on: January 16, 2007, 04:31:41 AM »
Survey Grade GPS equipment cost a whole lot more than recreational gps units. L1 phase units cost in the neighbor hood $3,000 for static positioning, and L1 & L2 phase units cost about $30,000 per pair for RTK positioning.

Static positioning requires post processing data to known reference station being a HARN Station,

“High Accuracy Reference Networks (HARNs) are statewide GPS survey networks which form the highest order of monumented control for the National Spatial Reference System (NSRS). Comprised of an NGS-maintained Federal Base Network (FBN) at 100 km station spacing and a volunteer-densified Cooperative Base Network (CBN) at 25-50 km spacing, HARN stations serve as control for regional and local surveys.”

Or post processing CORS data, from a (Continuously Operating Reference Station). I do notice with my raw pre-post processed data of my L1 units that I may have positional differences as much as much as 30 feet between units. Meaning our survey grade gps units are no better real time than recreational gps units. But post processed data from a reference station is centimeter accuracy.

In doing recon work locating section corners, property corners, and land lines, we as surveyors have no better accuracy than a geocacher. Until we establish positional control. So being able to walk out with a recreational gps unit to find exact land corners is nothing more than a pipe dream.

With RTK equipment, (Real-Time Kinematic), positional control is established much the same as stated above. But with software processing data real time, one unit being used as a base unit, the other being used as a rover, communicating with radios or cell phones, positional data is centimeter accuracy.

One note about positional accuracy is this requires an open sky with no obstrubtion such as forest canopy, building, towers or such.
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Offline Siskiyou

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Re: lat/long for dummies? please help
« Reply #9 on: January 16, 2007, 05:14:25 AM »
Surveyor is on the mark.  As a crime scene investigator I would use a license surveyor in high profile cases.  The first time I had one use his backpack gps setup with extra batteries, and external antenna I was disappointed that he did not pop open his vehicle and plug into a printer and give me an instant map.  He explained to me that he had to take the information he gathered in the field back to the office because the data had to be processed.

I was disappointed but it was an introduction to gps surveying.  I had already mapped the area by hand, and compass.  But to sew up the case I needed the survey by a license surveyor. 

SURVEYOR I appricate your imput, keep it up.

Siskiyou
There is a learning process to effectively using a gps.  Do not throw your compass and map away!

Boycott: San Francisco, L.A., Oakland, and City of Sacramento, CA.

Offline victorcharlie

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Re: lat/long for dummies? please help
« Reply #10 on: January 18, 2007, 12:59:27 PM »
Forget Lat/long......learn to use UTM........much easier to use with a map......
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Offline Awf Hand

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Re: lat/long for dummies? please help
« Reply #11 on: January 30, 2007, 10:28:07 AM »
>>>>>>>>>The survey I got shows one corner at N 89 (degrees) 42'40"W  , N 00 (degrees) 34' 2" E.

I believe you are confusing line bearings (compass or grid) with lats and longs.  Surveyors seldom print a Plat/Map of Survey or Certified Survey Map with Lats/Longs on them.

I'd guess from your GPS handheld Lat/Long numbers that you're in Clark County..?
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Offline Awf Hand

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Re: lat/long for dummies? please help
« Reply #12 on: January 30, 2007, 10:30:20 AM »
I should add that I'm an RLS in Wisconsin.  You may PM me as well.
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Offline BoarHunter

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Re: lat/long for dummies? please help
« Reply #13 on: January 30, 2007, 10:38:40 PM »
Forget Lat/long......learn to use UTM........much easier to use with a map......

True, it is what the army uses. It is easier as it is based on a kilometer grid. Any ten year old kid in countries using metric can read a map, compute distance, determine slopes etc... with just a regular ruler.

What is amusing is that not many people knows that the survey foot is not the same as the regular foot ! OK, the diffeence is small but yet !

Offline SURVEYOR

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Re: lat/long for dummies? please help
« Reply #14 on: January 31, 2007, 01:40:50 PM »
Quote
  N 89 (degrees) 42'40"W  , N 00 (degrees) 34' 2" E.

Awf Hand by gosh you're correct! I should have caught that. I'm a PLS in Mississippi. No not many surveys publish Lat & Lon on a plat. I could if asked to. I gps control on just about every project. I get good adjusted posistions using CORS for control sites. It don't take long to figure publishing Lat Lon, or state plane coordinates on every plat is comming.
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Offline wipartimer

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Re: lat/long for dummies? please help
« Reply #15 on: January 31, 2007, 04:46:50 PM »
Yes! I am in Clark county. I finally dug out the survey agagin. The base for bearing is the Clark County coordinate system. So your saying that the numbers on the survey map are Not lattitude/longitude but the gps numbers are, is that correct? thanks for helping me along everyone :)
Mike



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Offline SURVEYOR

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Re: lat/long for dummies? please help
« Reply #16 on: February 01, 2007, 04:08:22 AM »
Yes! I am in Clark county. I finally dug out the survey agagin. The base for bearing is the Clark County coordinate system. So your saying that the numbers on the survey map are Not lattitude/longitude but the gps numbers are, is that correct? thanks for helping me along everyone :)

Yes that's correct.

N 89 (degrees) 42'40"W for a distant of so many feet

Let's say for example,

N 89 (degrees) 42'40"W - 500.00' (feet)

That would be the direction and length of the surveyed property line. Each property line has a course and distance.

  Metes and Bounds Property Descriptions
Metes and Bounds is a commonly used method of boundary surveying. Land titles, which are transferred by written documents called deeds, often include a metes (to measure, or assign by measure) and bounds (boundary lines or property limits) property description.

The descriptions have a point of beginning (POB), such as a stake, fence post, road intersection, or a natural feature such as a tree. The length and bearing of consecutive lines from the POB are given. Values that were historically represented in chains, poles and rods are now in terms of feet and decimals, and even metric units.

A precedence has been set in order to take a written description and find its location and physical appearance on the earth. In other words, it defines an order when reestablishing an old survey using a metes and bounds description. The following list indicates the order in which distances, directions or words are weighted when conducting the survey (in order to avoid conflict):


      •  marks or monuments (almost anything can be called for as a monument) in place
      •  calls for boundaries of adjoining tracts
      •  courses and distances shown in the original notes or plat.

If numbers are both spelled out and given as figures, words take priority unless other proof is available. The assumption is that it is more likely that someone would incorrectly transpose digits rather than misspell numbers.

The description of a land deed should always contain the following information:

    Point of beginning (POB) - This point must be identifiable, permanent, well referenced, as well as one of the physical property corners. Coordinates of this point, preferably state plane (SPC), should be given if known or computable.

    Definite corners - parcel corners must be clearly defined points (typically marked by 1" iron pipes) with coordinates if possible.

    Lengths and directions of the property sides - All lengths in feet and decimals (or metric units), and directions by angles, true bearings, or azimuth angles must be stated to permit computation of any misclosure error (the distance and direction required to close the loop, given measurement errors). The survey date is required and particularly important if bearings are referred to magnetic north.

    Names of adjoining property owners - It is important to know names of adjoining property owners to settle property disputes. This will help in case a gap or overlap exists between adjoining parcels of land, due to an error in the description.

    Areas - The included area is normally given as an aid in valuation and identification of a piece of property. Areas of rural land are given in acres or hectares and those of city lots in square feet or square meters.

 


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Offline Awf Hand

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Re: lat/long for dummies? please help
« Reply #17 on: February 01, 2007, 05:26:44 AM »
The (1934) post that you found sounds like a witness post, and likely doesn't represent the corner.  The corner marker will be near the ground and allow a surveyor to set up a tripod over the thing.  Contact Wade at Clark Co. Surveyor's office and tell him that you need a tiesheet for that corner.  You'll have to go to the courthouse for this.
The other corners will be marked with an iron pipe or bar set flush with, or maybe slightly below, the ground surface.  Consumer metal detectors are typically used for finding gold, silver, copper… and so may not work well for finding iron.  Surveyors use magnetic, or ferrous locators to find corner marks.  You might just have to use whatever you can find.  A compass will work –if you’re close enough.  Try hard to find one corner marker.  IF you can find one of these, mark it as a waypoint.  If your receiver gives you the option, “average” a position over a minute or so.  Based on work I’ve published in the past, the position that you collect will be less than 12 feet from the position that a “survey grade” system would collect/process.

Set your receiver then to “go to” the point you just collected, and you’ll see yourself dancing a bit, but you’ll be pretty close.  Walk the direction that you think the next corner is and keep your GPS set to “go to” your stored waypoint.  You’ll have a bearing and distance on the screen in front of you and this distance will be getting larger as you walk away.

You have the map in your hand and the line you’re walking is labeled (example bearing/distance only) N 89d-42’-31”W, 855.71’.  Think about where you are and where the machine is telling you to head.  You’re going to be looking at a bearing from where you are on the ground TO THE POINT that you stored.  Ditto for distance.  If your GPS can be set in feet, use that, if not, convert the distance (855.71’ = .162) to miles and use that.  Walk there and start searching around.  If you’re along a road, the surveyor noted the road width and centerline location.  Pace this out to your point to further narrow your search.
If you have no idea where to start at all, you can go to the following link:

http://www.co.clark.wi.us/Website/ClarkIMS/viewer.htm

but, you’d better have a high speed ‘net connection.  As you zoom in, you can see aerial photos that are much higher resolution than other “national coverage” sites will provide.

If you’re still lost, you may want to have a retracement survey done, or, if the surveyor who did the work is still around, he may come out and mark up the corners for you.  This likely won’t be free, but it will give you some piece of mind, should you be building, fencing, placing tree stands, or selling your land.

You’ve got a lot of good info here.  Datum transformations, legalese, and Lambert Conformals aside...
I hope you find this useful.

Surveyor- >>>It don't take long to figure publishing Lat Lon, or state plane coordinates on every plat is comming.
My response to this is that there better be a ton of metadata with regards to the reference network and adjustment used, so that these numbers can be legitimately replicated.  We're wrestling with ANOTHER height (H and V) modernization project that creates a system which is not readliy translatable to any of the NAD adjustments, nor can the published coordinates (currently) be converted to SPC or County systems.  I like my HARN, but I'm still a monument's rule kind of guy.  But, THAT is a whole different message board. ;D
Just my Awf Hand comments...