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  1. #1
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    Unhappy Coordinates in AutocAD

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    Hi. I have a dxf file from a client created using autocad. I have no idea what these coordinates mean -40 558.37E and -46 244.43 N. These are UTM? I need to convert to decimal degrees. How do I do this??

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    Without more information, it's hard to tell what's going on. Do those coordinates belong to a point or a line? Is the space a separator, the way they use a comma in the US, or are there actually four numbers? By "decimal degrees" do you mean you want latitude and longitude or surveyor's bearings?

    It's possible to import points that are given as northing and easting, then redefine your units as lat/long.
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    Embarrassed coodinates in AutoCAD to decimal degrees

    Thanks for replying so soon.

    I managed to extract the data into excel and this is what I got. All the coordinate values are of this format which I assume is an autocad format. I do not have AutoCAD so I cannot do any conversions using AutoCAD. I want to work in decimal degrees as I have to project the coordinates (be it lines, polygons, etc) in google earth as well as add it to my database which accepts decimal degrees. Your help is appreciated. Thanks.

    x y
    -38034.2924163296 -48867.3372111626 0 0 SiltTraps
    -38013.678428361 -48847.8046473652 0 0
    -37996.5068603859 -48832.2203675267 0 0
    -37964.8317044261 -48828.9999965541 0 0
    -37946.2132784493 -48834.7376294894 0 0
    -37906.8326254954 -48848.147311339 0 0
    -37838.5683475833 -48844.9691993583 0 0

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    It is quite unusual to have negative coordinates in a UTM system. The datum of each zone is chosen so that all coordinates are positive.

    Could you reveal where in the world the site is, and someone might get some inspiration

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    datum is Lo 31, coordinate system clarke 1880. It is in africa. I just cant seem to understand these values. At a total loss
    Please help!! The above values are x and y coordinate values. But What coordinate values I have noooo idea!!

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    Does this look like the place? Not very good resolution in Google Earth.
    Attached Images

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    0°25'42.88"S
    30°38'59.16"E

    These are the exact coordinates

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    Rather the coordinates fall witin this area. ;-)

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    I have run out of inspiration, but using Google Earth, your coordinates are about 38000m west of 31degreesE and 48000m south of the Equator.

    The central meridian of zone Lo31 is 31 degrees east. Usually the central meridian is given a coordinate of 50000e so that coordinates do not go negative. As I have only worked in the Northern Hemisphere, I have only been using positive coordinates.

    So I would guess that your coordinates are in metre units from a point 31°E on the Equator. Negative going Westwards, and Southwards. I am not sure why you have 10 places of decimals, rather too many for practical use.

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    If someone on here has Autocad Map 3d, you could get them to convert your coordinates from the Clarke 1880 system to WGS 84 according to this: http://forums.autodesk.com/t5/AutoCA...4/td-p/2535281. Failing that, there is a converter here http://www.rcn.montana.edu/resources...ordinates.aspx

    As a side note, the Clarke 1880 system is also referred to as the "Cape" coordinate system for those who might be more familiar with that term.
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