Survey Trimble Points at Lat/Long and Autocad Basemap are at different coordinates

[David Davis]

I believe I have found the answer here on AUGI Forums under:
Lat/Long & NAD83 Conversion.


Seems to be just a conversion process.


I am trying to import my Surveyor's Trimble points which were sent to me in Lats/Long into my Basemap which has coordinates from an unknown source, The basemap is a converted dgn to dwg file, - (I have tried using convert with subbase as well). The Basemap is to scale as it is a Road in New Jersey and everything lines up with the Aerial Maps. But the coordinates are not Lat/Long in the Basemap. I have tried scaling using the points but it does not scale uniformly. - When I import his points they measure: 34.0881 apart, while my Basemap corresponding point locations measure: 32,976.1427 (which is the correct distance in the real world) . So my Basemap is scaled up by 967.38 from the lat/longs. But if I use this as a scale factor, the Lat/Long points do not fall into place. or If I scale by reference they still do not line up correctly. (I am not sure what my reference point would be, 0,0,0?)
I am hoping someone has some experience with this as my Surveyor is sending me points from GPS Trimble using these Lats/Longs coordinates and they must fall into my Basemap correctly..

The Lat/Long point coordinates are:

Pnt No.1
x= -74.1384
y= 40.1017

Pnt. No. 2
x=-74.0997
y= 40.1865

whilst my Basemap corresponding locations are:

Pnt No.1
x= 593253.839
y= 462165.7184

Pnt. No. 2
x= 603593.9213
y= 493478.7937

btw, He sends me .dxf files.

Is there some way to convert these Lat/Long points to my coordinates?

He also sent me a .csv file from another project close by in csv format which I am attaching. I am not sure if this is relevant but it shows his coordinates and ALOT of other information. I had to rename it to .xls for uploading - but the csv looks the same.

[Jmurphy]

Take a look at Corpscon.