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Easting/Northing conversion I'm lost... help!

#1 User is offline   Coach88 

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  Posted 19 October 2008 - 07:31 AM

Hi, I've been searching all over the forums and the internet and still can't find what I'm looking for... :)

I have a surveyor map for a piece of property in NB, Canada. The stakes/pin locations are marked in Northing and Easting. This ain't much help if I want to enter in my GPS in Degree & minutes. I've seen various websites that convert to UTM or NAD27 to NAD83 but nothing to convert Northing/Easting to Degree & minutes....

For example here are the coordinates for one pin: Easting 2643439.145 Northing 7475081.373

Can anyone help me please?

#2 User is offline   LSUFan 

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Posted 19 October 2008 - 09:07 AM

View PostCoach88, on Oct 19 2008, 10:31 AM, said:

Hi, I've been searching all over the forums and the internet and still can't find what I'm looking for... :anicute:

I have a surveyor map for a piece of property in NB, Canada. The stakes/pin locations are marked in Northing and Easting. This ain't much help if I want to enter in my GPS in Degree & minutes. I've seen various websites that convert to UTM or NAD27 to NAD83 but nothing to convert Northing/Easting to Degree & minutes....

For example here are the coordinates for one pin: Easting 2643439.145 Northing 7475081.373

Can anyone help me please?


Coach88, Eastings and Northings are the components of the UTM system, which is just one of the many different coordinate systems. However you have too many numerical places for your eastings to be UTM.

NAD27 and NAD83 are what's referred to as datums and mean something else.

This might explain it a little better:

http://www.colorado.edu/geography/gcraft/n...s/coordsys.html


I am confident that you will receive a better answer than I could provide shortly, by ones who are a lot smarter than me. :D

This post has been edited by LSUFan: 19 October 2008 - 09:43 AM


#3 User is offline   Coach88 

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Posted 19 October 2008 - 09:49 AM

Thanks for your info LSUFan, I'm sure it'll be helpfull. The more input the better!

#4 User is offline   Coach88 

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Posted 19 October 2008 - 09:53 AM

I found a trial software Franson CoordTrans but I don't get the expected resulst when I enter the coordinates...

#5 User is offline   DaveD 

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Posted 19 October 2008 - 11:19 AM

Do you have an approximate lat/long. UTM zones 19/20 cut right through NB so it would be important to know which zone these coordinates are in.

#6 User is offline   Coach88 

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Posted 19 October 2008 - 12:09 PM

I believe it is in UTM zone 20. The folowing coordiates are approximately where the property is located: N46 15.649 W64 38.337

#7 User is offline   tosborn 

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Posted 19 October 2008 - 01:30 PM

The Northings and Eastings you have are not expressed in UTM (it would be zone 20 if they were). What you have are Northings and Eastings expressed in New Brunswick Stereographic Double projection, NAD83(CSRS), meters. You can read more about it at http://www.snb.ca/e/6000/6904e.asp. On that page they list a utility called NBGeocalc that can be used to covert to and from New Brunswick Stereographic Double projection. It appears that it costs $100....wow!

I entered the Lat/Long coordinates you provided in Manifold GIS and then changed projection to New Brunswick Stereographic Double projection and got a Northing and Easting very close to the ones you listed in your initial post. If you have a limited number of Northings and Eastings, post them here and I'll convert them to Lat/Long for you. For example, Easting 2643439.145, Northing 7475081.373 from your initial post converts to Latitude 4615.63813 N, Longitude 6438.35750 W.

This post has been edited by tosborn: 19 October 2008 - 02:11 PM


#8 User is offline   Coach88 

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Posted 19 October 2008 - 04:38 PM

Wow tosborn, that's a great help... I have three other points that I'd like to have converted. Here they are:
N2643590,696 E7475159,228
N2643820,656 E7473958,269
N2644020,655 E7473993,734

Is it very complicated to learn how to do the conversion on my own? Other than the 100$ software, can I do the conversion myself? You used manifold GIS; is that a special software?

Again, thanks for your help!

Coach88

#9 User is offline   tosborn 

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Posted 19 October 2008 - 07:24 PM

I think you got your Northings and Eastings reversed in your last response. Here are the converted coordinates:

Posted Image


There are equations to convert the NAD83(CSRS) / New Brunswick Stereo coordinates back to Lat/Long, but I don't have a ready source and such equations are often pretty hairy.

Manifold GIS is Geographic Information System software. Their website is: http://www.manifold.net.

#10 User is offline   tosborn 

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Posted 19 October 2008 - 09:31 PM

On doing your own conversions..............

There is a free application called FWTools (http://fwtools.maptools.org/). If you download and install it, it contains a command-line utility called CS2CS which can be used to perform transformations between source and destination cartographic coordinate systems. Basically you would double click the FWTools Shell icon that is placed on your desktop, then type-in or cut and paste the following command as one line:

cs2cs +proj=sterea +lat_0=46.5 +lon_0=-66.5 +x_0=2500000 +y_0=7500000 +k_0=.999912 +datum=NAD83 +to +proj=latlong

then hit enter.

At that point you can enter an Easting and a Northing, in that order, all on one line separated by a space such as:

2643590.696 7475159.228

then hit enter.

The converted longitude and latitude will then be displayed on the next line such as:

64d38'14.29"W 46d15'40.701"N 0.000

The third number 0.000 I think represents ellipsoid height, which we didn't enter anything for so naturally it is 0.

You can then enter additional Eastings and Northings in the same way.

#11 User is offline   tosborn 

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Posted 19 October 2008 - 09:32 PM

...

This post has been edited by tosborn: 19 October 2008 - 09:32 PM


#12 User is offline   Coach88 

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Posted 20 October 2008 - 04:13 AM

Thanks for all the info. Very much appreciated!

#13 User is offline   timz2 

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Posted 23 October 2008 - 02:40 PM

If you still want formulas--

USGS Professional Paper 1395 "Map Projections: a Working Manual" by John P Snyder, 1987, has formulas for the stereographic projection on the ellipsoid. No idea how well they match the "double stereographic" that NB uses.

The library here has a paper copy, if you want xeroxes.

#14 User is offline   tosborn 

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Posted 23 October 2008 - 03:54 PM

Double Stereographic is better know as Oblique Stereographic. The formulas for Oblique Stereographic can be found in the following publication beginning on page 46. An example computation is shown on page 48. It's not something one would want to attempt with a handheld calculator.

http://www.epsg.org/...s/docs/G7-2.pdf

#15 User is offline   tosborn 

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Posted 25 October 2008 - 07:47 PM

Coach88:

I've written a small utility to do conversions to and from New Brunswick Stereographic double (NAD83) and Lat/Long (NAD83). It implements the equations in the document I linked above. If you are interested you can download it from this LINK. Run the program and it will install the small utility. You will also need Microsoft .NET Framework version 2.0 or later installed on your Windows machine. Note that data entry requires that you use periods for decimal points rather than commas. I have tested the program on a number of conversions and everything appears to be working correctly, but use at your own risk. When converting from Lat/Long to Northing/Easting you can enter lat/long in any number of formats. For example decimal degrees (e.g. 46 or 46.1 or 46.12343), or degrees and decimal minutes (e.g. 46 38 or 46 38.1), or degrees, minutes and decimal seconds (e.g. 46 38 12 or 46 38 12.4 or 46 38 12.4352322).

This post has been edited by tosborn: 25 October 2008 - 07:52 PM


#16 User is offline   bconnors 

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Posted 11 August 2010 - 06:20 AM

The NBGeoCalc software is now a free download. It may not run on a 64 bit operating system such as Windows 7. The URL is: http://www.snb.ca/gd...e/NBGeoCalc.zip.

Bernie.

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