Overlay points on aerial photo

[GmoCAD]

I have a set of elevation points depicting a one mile stretch of levee. How can I overlay this points on an aerial photo of the area to show where the points fall on the levee.

 

I am using AutoCAD v 9.0 and ArcView v 9.3

 

Thanks

[BIGAL]

1st You can rescale an aerial photo brought into Acad

 

2nd you need two known co-ordinate points on your photo this sets the rotation angle as well as at the same co-ords of your levee. If you dont have known points then its probably best guess. we use stuff like fences and light poles (watch for shadow)

 

3rd theres lots of input xyz files using lisp here on the forum.

 

4th job all done add discalimer re accurracy.

[GmoCAD]

1st You can rescale an aerial photo brought into Acad

 

2nd you need two known co-ordinate points on your photo this sets the rotation angle as well as at the same co-ords of your levee. If you dont have known points then its probably best guess. we use stuff like fences and light poles (watch for shadow)

 

3rd theres lots of input xyz files using lisp here on the forum.

 

4th job all done add discalimer re accurracy.

 

 

I did try to rescale the photo but maybe i was not doing it correctly that it never aligned right.

 

How do I work the coordinate point into AutoCAD ?

 

What do you mean by "theres lots of input xyz files using lisp here on the forum."

 

Thanks for all your input, if all else fails we will probably have to buy more software to be able to export/import photos and or elevations.

[BIGAL]

If you "Insert" a raster image then its like a block you can scale it and rotate it we use jpg's

 

We measure the distance between two points on our mapping system and then compare them in the photo and work out a scale factor, usually do twice, if we have ground survey then we compare the two same points to work out a scale factor.

 

Where did your photo come from ? company a to company b to c to d etc hence no idea of original measurements. Try google earth etc you have to establish at least the co-ords of one point two is generally minimum. Our photos are correct in the xy sense so if our surveyors have field info in MGA zone 55 etc the photo can be easily aligned and scaled.

 

Often our surveys are arbitrary small street works the surveyor points the instrument towards North and sets to 0. Hence photo does not align but as I have said use two points ! Scale & rotate or just use "Align" (caution on Align if data has Z's)

 

re XYZ file you said you had survey points if they are a drawing already then start at that point. Else read in the data file.

 

Final note went back and read your first post can you not get Xy co-ords out of your arc view ?

 

Finally two if you levee survey has no ties to anything elase around it fences titles etc , true world co+ordinates, then best guess is all your going to get and also get new surveyors.

[BIGAL]

My House with points used boundary to match

[Patrick Hughes]

If you "Insert" a raster image then its like a block you can scale it and rotate it we use jpg's

 

We measure the distance between two points on our mapping system and then compare them in the photo and work out a scale factor, usually do twice, if we have ground survey then we compare the two same points to work out a scale factor.

 

 

BIGAL and GmoCAD, you might want to look into SCALE > reference. It allows you to pick two points on your image and scale it to a pick point of your geometry. Let AutoCAD do the calculating. You'll want to position your image to a basepoint first. It takes a little practice.