Google Earth™ and AutoCAD
Bringing Together the Best of Two Worlds with GPS2CAD-08
by Mark Crigler, P.E.
The Best of Two Worlds
Have you ever played with Google Earth™ and wished you could get those great images into your AutoCAD drawing? Well a great new feature of GPS2CAD-08 is the ability to bring custom bit-map images into the program, calibrate the image, and plot the points and lines from your GPS unit. Then with the click of a button, the image and point data can all be sent into your AutoCAD drawing, ready for you to draft over. The coordinates translation is done correctly and the data is placed correctly in your drawing!
While this feature is designed to work with any bitmap image source, one of the most popular is Google Earth™. This article is designed to show how it’s done.
GPS2CAD-08 is designed to reduce the cost of data collection for architects, engineers, and other design professionals. It bridges the gap between handheld GPS units and AutoCAD. For more on this program, visit the website at www.GPS2CAD.com
Find your place in the world
For starters, you need an image to work with. Using Google Earth™, zoom into the area that encompases the GPS data you are working with. Zoom out a little bit extra to allow for some margins. If you have purchased an upgrade to Google Earth™ (well worth it!) you can plug into your GPS unit and import the points. While you will also be doing this in GPS2CAD, sometimes it helps to check the area you’re working on.
Next, you need to place two “calibration points” on the drawing. Using the “placemarks” feature, set one in the upper left corner, and one in the lower right. With the mouse cursor, hover over the points and write down the coordinates displayed in the legend. You will need these later for the calibration.
Leaving the points on the image, save the image to your computer.
Calibrate with Earth2CAD
The next step is to calibrate and import that image with the new Earth2CAD feature of GPS2CAD-08. This feature is a simple wizard, only a four steps long
- In GPS2CAD, click on the maps button to take you to that area of the program, then click on the Earth2CAD button which starts the wizard
- Click next, which will take you to the panel entitled Step 1. Select the image you just saved from Google Earth™, and then click Use image. You will see the image appear in the window behind the wizard. Click next
- Use the mouse to left-click on the calibration point in the upper left area of the image, and enter the Latitude and Longitude coordinates in the text boxes. Click next
- Repeat the process with the lower right point. Click next
- Click the Validate Input button, which tests that you have entered the data correctly. If there is an error, go back and correct it, otherwise click Calibrate
That’s all there is to the Earth2CAD wizard, close it and return to the main program.
Send to AutoCAD
In the Maps panel of GPS2CAD, examine the imported map. Notice that as you move your mouse over the image, the coordinates are shown in the bottom status bar. Here are the remaining steps:
- If you want to view your GPS data over the image, go to the GPS panel and import the points, then drag-select the points you want to display Return to the maps panel and click the Show Points / points, labels, lines, and grid as desired.
- Send to AutoCAD –make sure the correct version of AutoCAD is running with a drawing started. Then simply click the button “Send Map to ACAD”. The image will be sent into the AutoCAD drawing correctly scaled and located.
- You probably want your GPS data plotted in the drawing as well. To do this, return to the GPS panel of GPS2CAD-08, and click “Plot in ACAD”. The GPS points will be sent into AutoCAD as actual drawing items that you can work with. Just to test it out, go into the drawing and hover your mouse over the data. You will seem them highlight themselves, especially the polylines. That’s all there is to it!
The process is really quite simple, especially considering the value it has to the drawing production effort. I have also produced two videos that show the process start-to-finish, and follow the procedures outlined in this article. You can view them on the GPS2CAD website at http://www.gps2cad.com/videohelp/index2.htm
I hope this demonstrates the value of GPS2CAD-08 and how this remarkable program can be used to help reduce the costs of field data collection.