conversion of autocad coordinates x, y into lat long

hi,

is there any addon to directly convert x,y units into lat longs , ie setting limits and units from autocad sw itself?

Sounds like someone is fishing for an easy way to do their home work. There is a reason you need to learn how to do it long hand rather than cutting corners. There is free software to do coordinate transformations though but not in vanilla AutoCad. AutoCad Map 3D has some functionality for doing something similar but you need to know how to use it.

I have been struggling with this question for a long time. Neglecting spherical distortion the problem should be generic, finding a conversion factor for units of x to units of longitude, another factor for y to latitude and then offsetting the origin reference between the two systems. Sounds straighforward, but I still haven't found the answer.

Coordinate conversion.

http://www.ibm.com/developerworks/java/library/j-coordconvert/

We work in real world coordinates all the time, but they're not lat/long, they are State Plane Coordinates, part of the North American Datum 1983.

From http://www.ngs.noaa.gov/faq.shtml#WhatNAD :

The North American Datum of 1983 (NAD 83) is "The horizontal control datum for the United States, Canada, Mexico, and Central America, based on a geocentric origin and the Geodetic Reference System 1980.

"This datum, designated as NAD 83, is the new geodetic reference system. ... NAD 83 is based on the adjustment of 250,000 points including 600 satellite Doppler stations which constrain the system to a geocentric origin."

All of our survey data is recorded in this system in the field, so it's never an issue. When we download the data from the Total Stations, it's already there.

As far as converting the coordinates, I use a free program called Corpscon6. It allows you to put in your ZONE and your DATUM information for both your INPUT and your OUTPUT. Also you can do individual conversions or a USER DEFINED FILE all at once. Works great for what I need.

 

http://crunch.tec.army.mil/software/corpscon/corpscon.html

Here's what I use but it only applies to work in the USA.

I made an Excel file that will convert Lat/Long to X/Y. It's at home though.