Nearmap to MicroStation (Jpg)

RE: Nearmap to MicroStation (Jpg)

Lorys — Fri, 30 Oct 2020 22:26:22 GMT

From memory Nearmap is not ortho corrected. So the greater the height of objects above ground the greater parallax error or mismatch between ground and heights so your never going to to get perfect alignment relative to real survey ... especially say a freeway ramp over a road or tall building tops will tilt over and actually fall outside their surveyed base or title. But you get what you pay for...

Before we had Nearmap you needed to get a flight run for you if there was no library recent stock films, and then you paid a little extra for it to be ortho corrected this was done with overlapping photoruns and clever optics and it helped to reduce the parallax error...I believe this is still available from some agencies and is now done with clever programming and overlapping photos... but might be expensive to pay on top of nearmap.. ask near map if they offer the extra service for a specific site... but how perfect do you need it.. at what scale are you going to print anyway... my stuff is usually never more than 500 mm out, even if I capture it from Google Earth pro ( for free) that's not bad .

So now if you have survey you can adjust the position of the photography in your drawing sheet view to make it better you'll never get it perfect for large areas and it also gets worse around the edges ( I think due to the curvature of the earth) .. Well thats my 2 cents worth..

RE: Nearmap to MicroStation (Jpg)

Bob Rayner — Fri, 30 Oct 2020 21:24:51 GMT

How much off? millimeters or meters? You might try attaching it with a different orientation.

RE: Nearmap to MicroStation (Jpg)

Rousenator — Fri, 30 Oct 2020 06:15:53 GMT

In my experience it is not uncommon for Nearmap Imagery to be 'slighly off'. I generally have to attach it interactively and modify to suit existing CAD linework.

RE: Nearmap to MicroStation (Jpg)

Lorys — Thu, 29 Oct 2020 02:38:03 GMT

can you open the jgw file with note pad and post the contents here as a lot of the settings are in this txt file...

Have you other similar rasters in us survey ft open the jgw file and compare it with the problem one if same datum and same units then most of the settings will be the same except for the origin xy

RE: Nearmap to MicroStation (Jpg)

Ron Jones — Wed, 28 Oct 2020 04:28:41 GMT

What are the Working Units>Advanced Settings?

[quote userid="713053" url="~/products/microstation/f/microstation-forum/205102/nearmap-to-microstation-jpg"]the coordinates are slightly off [/quote]

How far is "slightly off"?

RE: Nearmap to MicroStation (Jpg)

TN — Tue, 27 Oct 2020 20:27:34 GMT

I have all those settings matched up too. Are there any other settings that would say limit the digits on the scale?

RE: Nearmap to MicroStation (Jpg)

Rod Wing — Tue, 27 Oct 2020 18:23:56 GMT

Take a look at your User Preference settings under the Raster Manager category.

There is a Georeference tab that allows you to set the units of the World File (Sister File), and the units of the raster file. Both of these settings default to Meters. Change them both to US Survey Feet.

You will also want to toggle on the checkbox to Use Sister File, but leave the Save Location checkbox unchecked.

This image is from CONNECT, the V8i version has the same options, just formatted a bit differently.

RE: Nearmap to MicroStation (Jpg)

TN — Tue, 27 Oct 2020 16:19:17 GMT

Yeah, I've tried with and without both set to the nearmap jpg export coordinate system. Neither matches up with the jgw coordinates. Is there a setting that controls the digits of the raster import? Seems that the scale could possibly be getting rounded.

RE: Nearmap to MicroStation (Jpg)

MaryB — Tue, 27 Oct 2020 16:12:03 GMT

Do you have a coordinate system set in your DGN?

RE: Nearmap to MicroStation (Jpg)

TN — Tue, 27 Oct 2020 15:40:13 GMT

If the working units are set to US Survey Feet and the nearmap export is the same, shouldn't the jpg attach to the correct coordinates?

RE: Nearmap to MicroStation (Jpg)

Ron Jones — Tue, 27 Oct 2020 15:33:20 GMT

Your dgn working units settings may be affecting the accuracy of the attachment. It's really hard to say without having the dgn, jpg, and jgw to understand all the possible causes of this issue.