Lat, Long csv

[kari_sinkko]

Hi,

 

I have a csv file that has let,long,meters and was wondering how to import it.

 

I'm thinking there would be a script that would read it in the csv and show the lat long and meters.

 

Been searching a bit now, it seems to be quite complicated. Using Autocad Architecture 2010.

[stevesfr]

Please post a couple lines of your csv file here and I'll try to find something in my toolbox that may help the import.

Is the latitude data north or south of the equator? (meaning does it contain the correct + or - prefix)

Steve

[stevesfr]

Hi,

 

I have a csv file that has let,long,meters and was wondering how to import it.

 

I'm thinking there would be a script that would read it in the csv and show the lat long and meters.

 

Been searching a bit now, it seems to be quite complicated. Using Autocad Architecture 2010.

 

This may help:

http://www.cadtutor.net/forum/showthread.php?42954-Point-Manager&highlight=ptmanager

[kari_sinkko]

Lat Lon Elev.(meters)

-28.04415 145.94878 195

-28.1118 145.8129 190

-28.07695 145.81922 189

-28.1774 145.80974 188

-28.0708 145.87768 191

-28.0626 145.8208 192

-28.2102 145.8524 192

-28.1159 145.8998 191

-28.1979 145.89664 184

-28.2184 145.92666 185

-28.1938 145.85714 190

-28.0421 145.80658 194

-28.2143 145.83344 185

-28.09335 145.92508 192

-28.1282 145.84766 189

-28.20815 145.85082 187

-28.17125 145.88874 186

-28.1159 145.93298 192

-28.0708 145.8287 191

-28.11795 145.95352 188

-28.2348 145.91244 196

-28.0421 145.88242 192

-28.2266 145.83818 184

-28.08105 145.8998 192

-28.1692 145.85398 186

-28.1118 145.95036 189

-28.05235 145.8998 192

-28.08105 145.90296 192

-28.16715 145.81606 185

-28.1733 145.88558 186

-28.07695 145.95352 191

-28.1487 145.88558 188

-28.1774 145.8287 185

-28.1815 145.81606 188

-28.24095 145.83028 183

-28.0708 145.95036 194

-28.15895 145.8129 187

 

 

 

 

This may help:

http://www.cadtutor.net/forum/showthread.php?42954-Point-Manager&highlight=ptmanager

[kari_sinkko]

Oh yeah stevesfr, it looks like that link to the pt manager might just be the thing. Didn't mean to think that I should search for xyz !

[Lee Mac]

Thanks for the recommendation Steve - I believe my program will work with any combination of xyz, but I've never worked with Lat/Long so I'm not sure if there is a conversion needed somewhere along the line.

[eldon]

What some folk do not seem to realise is that Latitude and Longitude refer to a sphere, and one degree in Latitude does not equal the same distance as one degree in Longitude, except at the Equator. One degree in Latitude at the Equator is about 111km, but at the Poles it is zero length, but is still one degree. So it varies, but not evenly because it is going round a sphere. And then the Earth is not a regular sphere, it is an oblate spheroid. There is no way that ordinary AutoCAD can deal with these coordinates. You have to go for Civil 3D or something with geographic capabilities which has the complicated calculations built in.

 

If you merely convert the Latitude and Longitude figures to a decimal and plot those, the result is a complete nonsense.

 

Perhaps a bit of reading from a web search will help to convince you that the process is not simple

[stevesfr]

What some folk do not seem to realise is that Latitude and Longitude refer to a sphere, and one degree in Latitude does not equal the same distance as one degree in Longitude, except at the Equator. One degree in Latitude at the Equator is about 111km, but at the Poles it is zero length, but is still one degree. So it varies, but not evenly because it is going round a sphere. And then the Earth is not a regular sphere, it is an oblate spheroid. There is no way that ordinary AutoCAD can deal with these coordinates. You have to go for Civil 3D or something with geographic capabilities which has the complicated calculations built in.

 

If you merely convert the Latitude and Longitude figures to a decimal and plot those, the result is a complete nonsense.

 

Perhaps a bit of reading from a web search will help to convince you that the process is not simple

 

I certainly agree with your statements. However, If all the Lat-Long data is from a relatively small area as opposed to hundreds of miles or kilometers, then the error isn't significant. For example if one were to map data of good fishing locations on a small body of water, then plotting this data (without correction) on a map of the lake is close enough and darn near perfect. The correction would probably be out in the dozens of decimal places.

There are programs which will make corrections to the data, given the "center" Lat-Long of your data. One I can think of is CORPSCON or something like that.

[eldon]

However, If all the Lat-Long data is from a relatively small area as opposed to hundreds of miles or kilometers, then the error isn't significant. For example if one were to map data of good fishing locations on a small body of water, then plotting this data (without correction) on a map of the lake is close enough and darn near perfect. The correction would probably be out in the dozens of decimal places.

 

If the lake were near the Equator, then I would agree. Otherwise the horizontal distortion is more than the correction that you are quoting.

 

I find that for small quantities of data, then Google Earth is perfect

[kari_sinkko]

Oh yeah, cool thanks, yes, I can see your issue eldon, stevefr I'll look up and see what error difference it makes. What is Civil 3d?

[Lee Mac]

http://www.lmgtfy.com/?q=AutoCAD+Civil+3D

[kari_sinkko]

Oh thanks Lee Mac, that's quite a good way of showing Google as I didn't havethe time to look it up at the moment so I think your being cynical. Didn't know Autodesk made a program called Civil 3d. Might look into that, when I have the time

[Lee Mac]

...as I didn't havethe time to look it up at the moment so I think your being cynical.

 

Not really going to pursue this, but you had the time to post/reply in the time that I googled it so...

[kari_sinkko]

I've found a program called Surfer, that look like it can handle the data I'll let you know.