GROUND OBJECT IMAGE IMPORTED FROM GOOGLE EARTH

[DAVID DIAZ]

Hi Andre,

I am trying to use an imported GOOGLE EARTH image to model a layout. The problem I am facing is that the horizontal measures taken with the measure tool in PVsyst match with the measures on GOOGLE EARTH. But any measures not 100% horizontal over the imported image in PVsyst doesn´t match with the ones measured in GOOGLE EARTH. Therefore, I can´t use the imported ground image as a base to create a layout, by creating a zone and fill it with tables. I know that the acurrancy of GOOGLE EARTH is not very high, but in 900 meters in GOOGLE EARTH from north to south I get less than 730 m in PVsyst.

I have converted the google earth images to .BMP format, so I am not able to find if there is anyway to do it right.

Best

[André Mermoud]

You can only use the background image in the Plane view in PVsyst. Therefore importing images which are not a plane view doesn't make much sense.

[DAVID DIAZ]

Hi Andre,

I used it only for the XY view. As written in PVsyst Help menu:

"In the near shadings 3D editor, you can use menu "File > Import > Import Ground Image" to import an image or a plan of the scene ground. This file must be in BMP or PNG format. Importing a ground image helps to set position and dimension of the PV and shading objects when building the global scene. The user is responsible to provide the ground image. He can use for example a Google Map in earth view of the PV system area.

Note that PVsyst is expecting a Ground Image captured in 2D and showing the ground at 90 degrees. Once imported in the PVsyst 3D editor, the Ground Image will be visible only when top view is selected. Here is an example of Ground Image captured from Google Map."

So, I think I did it as the instructions stated. But I used GOOGLE EARTH, not GOOGLE MAPS. Is there any difference between GOOGLE EARTH and GOOGLE MAPS when importing the ground image?.

Best

[Soldnerkugel]

How is the scale defined in PVsyst?

Using google maps or google earth should not make any difference as for a few years both products use the same data (afaik). In standard google maps is using geographical coordinates in WGS84 (DMS). So importing a bmp or png most probably is without any scale. Even of google maps should UTM projection (metric) saving an image will most probably get rid of the scale, additionally UTM uses a scale of 0.9996 and UTM grid north is not "true" north due to mapping a "sphere" to a plane view.

Maybe using a so called "world file" could solve this issue. Example if you use a *.tif you would also need to use a file with extension "*.tfw", wich contains onl six lines with information about scale and rotation. Such world files are common within GIS and exist also for other image formats like jpg etc.

[DAVID DIAZ]

Thanks Soldnerkugel, but that was too much for me ;).

I just was trying to do it thinking that it was just going to Google earth, importing the ground image in PVsyst (as was written in PVsyst help) and that was it, but clearly is not. Maybe for small fields it may work, but for MW scaled installations won´t due to the big unaccurancy of the measures NORTH TO SOUTH. It´s a pity.

André, can I suggest you to state this problem in the help menu?. Maybe other user may think that using imported ground images from google earth as a base for the layout is a good idea, but then they would face problems.

Thanks a lot.

[André Mermoud]

PVsyst supposes that you use an image which is a plane view. You cannot use an image seen from a not vertical view.

I don't see the problem for getting such an image from GoogleEarth.

[SE2015]

I guess the question we are having is how to change the scale of the image. Most likely we will always need to change the size of the image a bit after we import it.

I am personally very confused by the X1 and X2 parameters.

[rouge26]

The problem that I have when importing a ground image to PVsyst is scaling it. When selecting X1 and X2 and setting the distance between these points The image is not scaled to the distance I entered but always to 100 meters. When I measure the distance with the measuring tool in PVsyst I get exactly 100 meters and not the distance that I entered which in this case is 366 meter. I cannot get it to work. Any ideas?

Thanks.

[Sylvain Pepoli]

Make sure you click on "Apply" after you defined the X1 and X2 points or else nothing will happen.

[rouge26]

Make sure you click on "Apply" after you defined the X1 and X2 points or else nothing will happen.

Thanks Sylvain.

Has anyone experience problems with the ground object scaling being removed after reopening the project? I have experienced this with different projects and it is time consuming having to re-apply scaling with correct referenced dimensions. I am wondering how could I avoid this? Thanks.

[dtarin]

Make sure you click on "Apply" after you defined the X1 and X2 points or else nothing will happen.

Thanks Sylvain.

Has anyone experience problems with the ground object scaling being removed after reopening the project? I have experienced this with different projects and it is time consuming having to re-apply scaling with correct referenced dimensions. I am wondering how could I avoid this? Thanks.

 

Update to 6.64.

http://forum.pvsyst.com/viewtopic.php?f=4&t=3036&p=7765&hilit=ground+image#p7765