Hi, I am having problem importing data from two different source. The first one is hypso data and is supposed to be in lat / long from the CSRS. When I import the shape file in C3D using these specification, the white arrow appears in the center of the drawing, and everything seems fine.
Now then, I have those data point from land survey with a GPS I wish to had to my surface. When I import my text file ( which is in P - X - Y - Z format ), the point appears way offside of the hypso drawing.
So I was wondering, how can I know the system in which those point were recorded. Once I know this, how can I speicify to C3D that the hypso is in a certain system, and the GPS point in another one, so that they will come togheter ? Thanks !
Before you start importing anything, right click on your drawing name in the seetings tab of toolspace and make sure that the coordinate system in your drawing is set (See screenshot). The easiest way would be to set it to the same system that the survey information was delivered in.
The shapefile will be converted from whatever datum it is in to the datum your drawing is using. That should fall in line with the points from your surveyor. The only way to be certain about which datum the surveyor used is to ask. Never assume anything.
I already checked this, I forgot to mention in the opening question !
But my drawing setting are set in the same coordinate as my shapefile. And I checked it was good. The problem comes when I try to add the GPS point from the land survey. They appear very far, in plan view, from the surface of the shape files....
If your drawing's zone is set to Lat and Long., you need to make sure the point file is also Lat. Long. If your point file is state plane Northing and Easting, you have to set the drawing zone to the proper coordinate zone, import your points and then import the shapefile. It is unusual (at least aoround here) for a point file to be in Lat. Long. The software will transform the shapefiles to the propeor location, but it can't do that with a .csv point file.
Yes. I agree with you, but I was so desperate I tryed many weird thing hoping it would work. Normaly, I would set the Nad-83 + the zone... but when I do this, the hypso looks in good place in plan view, but the points goes way out !
Are the points in a survey database? If so, what coordinate zone is it set to? Are you mixing meters and feet? Do you have an aerial or something you can drop in to verify that the points are wrong? If you're sure of the validity of the shapefile location, then it sounds like you need to ask the surveyor that provided the points what he did.
You will have to ask the person who created/provided the file what system it is in if they did not add any meta data to the file.
Once you know the two different systems you should make two seperate drawings with the appropriate system settings applied to each. Then you can use the map querry tools to bring data from one drawing into the other and have it converted.
Or, you could set up a survey database with system A, import one set of data, then set the drawing to system B and import the data from the survey database.
The point were taken usuing a GPS.
They do not appears to be " good " because when I superpose a google earth surface, its comes in good agreement with the shape files, but the points aren't even in the same country I guess ! I really have no clue about what is happening, I know there is a issue with the reference system, but I don't know anything else.. Is there a " standard " GPS reference system used in Cad drawing ? (maybe the question sounds a bit stupid, but am getting confused now...)