Working with Google maps · noise maps · GIS
1. Firstly you can can navigate to Google maps web.
2. Using the screen arrows move to the map area that you want to watch. For example, we can watch Garachico in Tenerife North.
3. For the image capture, it is possible to use in the keyboard Ctrl+Alt+PrtSc). In the keyboard you can push at the same time (Ctrl+Alt+PrtSc). In that way, the screen image is copied by the computer memory.
4. Open the windows PAINT program (Windows >> Start>> Programs>> Accessories >> PAINT).
5. To paste the image that has been previously copied in the computer memory, you can use the commands (Edit >> Paste in the PAINT program) or (Ctrl+V). You can watch now the copied image from the Google maps web page.
6. It is obvious that you don't want to watch the navigator bars that appears in the screen. Use the arrows of the PAINT program to center the image, that you are interested for, in your computer screen. In the toolbar of PAINT, you can use the icon SELECT (it is on top of the toolbar and at the right in the last picture). Drag the mouse arrow selecting the screen area that you are interested for. For our case, it is the rectangle where the picture of the terrain appears.
7. Copy now the selected area by the rectangle in the last image using (Ctrl+C) or the command (PAINT Edit>>Copy) in the PAINT program. Then, you can use the command (File>>New) in the PAINT to have a new and clear screen
8. Use (Ctlr+V) command in the keyboard, or (Edit>>Copy) in the PAINT program to paste the selected retangle. The copy of the image appears now in the PAINT screen. The scale of the map imported from Google maps appears now in our screen (marked by a yellow arrow). This will be of great interest in a near future. It is important to have this scale in the image that you have selected.
9. Save the file using BMP format using the commands of the PAINT program (File>> Save as. . .). Then, you can open the previously saved BMP file using the Canarina program.
10. To work in the correct scale, we need to check the scale bar width in the Google map. The Google scale bar is between the red and yellow arrows (in the next picture). The Google bar width is in meters. When we put the mouse pointer in the point of the red arrow we can see the X-Coordinate value in the box marked by a blue arrow. If we put now the mouse pointer in the point of the yellow arrow, we will obtain a new value for the X-coordinate. The difference between both values in meters must be the same that the original Google bar width in meters to be in the correct scale.
When we put the mouse pointer in the point of red arrow, it is found 7 m in the X-Coordinate box (marked with a blue arrow). If we do the same with the yellow arrow, we obtain 75 m in the box marked with a blue arrow. Then, and in our actual scale, the bar width have 75 m -7m = 68m. However, the correct value in the original Google scale is 100 m. The correcting ratio is
P = 100/68 = (real value)/ (our value).
11. To work in the correct scale, we have two methods:
We go now to Canarina program>> GIS >> Scale calculation in the program and we get
We replace the 300m value that appears in the last picture by 100m (the original Google bar width in meters) and 'click' ACCEPT. Then we click firstly in the left extreme of the original Google scale bar and secondly, we click again in the right extreme of the original Google scale bar (both points in the screen were market with red and yellow arrows in the last step 10). The imported Google map is now in the correct sale and we can check it. When we put the mouse pointer in the red arrow, we get an X-Coordinate value equal to 10 m (in the box market with a blue arrow). We can also get 110 m for the position market with the point of the yellow arrow. The difference is now 110 m -10m = 100 m. Such a value coincides with the original value of the Google map bar. So, the program scale is correct now.
We go now to Canarina program>> Tools >> Scale in the program and we get
Now we multiply (our actual X-Axis width) by P to get the correct X-axis width,
(correct X-Axis width)=Px(X-Axis width)
(correct X-Axis width)=1.47x1000=1470m
And we introduce the new X-Axis width and click ACCEPT in the last window. The imported Google map is now in the correct scale and we can check it. When we put the mouse pointer in the red arrow, we get an X-Coordinate value equal to 10 m (in the box market with a blue arrow). We can also get 110 m for the position market with the point of the yellow arrow. The difference is now 110 m -10m = 100 m. Such a value coincides with the original value of the Google map bar. So, the program scale is correct now.
12. Now we introduce a pollutant source and we make the simulation. The result can be exported to a BMP file using the Canarina software.
13. We can repeat the 6-7-8 steps 'in order to eliminate not necessary parts in the picture. At the end we have a clean image with both the Google map and the simulation process results.
noise maps · GIS
Canarina Environmental Software
Software for environmental consulting firms
Canary Islands, Spain
European Union · network on Pollution
Member of MAPO: European network on Marine Pollution.