How do You use Google Earth??

[hagg_koos]

Hey All,
It seems that most stuff I read on here and other places about Google Earth is how to get your data working in GE...but I'm interested in getting what's in GE into my database.
I'm curious as to how others are using GE, and if how I use it is the best way...

So this is how I do it:
I have the free version- so no real high res image output compared to the pro version
If there is a spot where I like the imagery, I put some small- (only noticeable to me) points (placemarkers) on the map at even lat's & longs, export it as an image, and the use those in the georeferencing Plugin to create a referenced raster in qgis- using linear georef mode.

Benefits I see:
-easy enough to scan and find a spot you need in GE
-Free
-reasonable quality imagery

Drawbacks I see
-can be tedious
-chance for errors (non ortho/non north, 'sphere-ing' at higher viewpoints)
-limit to the resolution you can get

What other ways are there for working with Imagery from GE? How do you use it?
post away!

Koos

[cfarmer]

Hi Koos,

Technically what you are describing is (likely) against the GE licensing agreement (illegal). However, having said that, there has been some discussion lately on the developers list about GE data in QGIS. I think the consensus is that it's not possible given the GPL license of QGIS, but it might be worth checking out...

Carson

[Sisophon2001]

I was playing with this yesterday and this morning. In Google Earth you can use the short cut key r to orientate the display north up with zero tilt. Then turn on grid lines (Ctrl-L) and save the screen as a jpg image (Ctrl+Alt+s). Without changing the view, save a second copy with a different name but without the grid. It is easy to georeference the screenshot with grid lines in qgis, and once you have created the world file, just rename it to the same base name as your screenshot without the grid, and load the image.

Google Earth provides the menu item to save the screen as a bitmap, so their intention must be that you use this menu item if required. I would treat the image as I would any other copyrighted image on my computer. I make use of it as needed, but do not redistribute it.

If you are a window user there are two shareware programs that will georeference GE snapshots automatically .

Garvan

[nhopton]

I'm always curious about why people would want to calibrate captured Google Earth images in the first place. In my (very limited) experience any GE view that covers a reasonable area doesn't have enough resolution to be of much use for tracing in GIS software.

It's much more convenient to trace features as points, lines and polygons directly in GE (where you can zoom to full-resolution and out again, as required) and export them as KML for converting to projected shape files which can be used in QGIS (or any other GIS package).

I've written a daft little mini-tutorial about one way of doing this:

http://www.confound.me.uk/maps/Beginning_MM_1.pdf

Regards, N.

[FiReSTaRT]

I've seen the images used to make report covers look pretty. It would show the general study area and then either the grid(s) of interest or even a graphical representation of the data. I guess low-res images can be used for the same purpose in school reports.

[Sisophon2001]

nhopton,

Nice tutorial. I use Linux, so I did not try the programs you recomend, but the same idea works in qgis which will happily read a GE kml file. I did not realise you could save a kml trace from GE.

Garvan

[vsheremeti]

nhopton,

Thank you for your tutorial.
I come from Kosovo, and .SHP maps here are very outdated, so being able to see roads on Google Earth makes drawing really easier. I have few questions if you can help me please:

1. I followed your instructions carefully, but when I clicked ‘File’ and from the drop-down menu selected ‘View in Google Earth’ in MM the GE poped up but it zoomed the view somewhere in Atlantic Ocean and did not match the polygons that I have created with the ones that exist on GE. I retried the same procedure, but again same problem.

2. Using GE I can successfully create KML files and I tried to make main road thicker and with different color than secondary roads that I make thinner, but how can I make the 'lines' show with colors and size when I import them on MM?

3. I do posses older .SHP files for Kosovo, can you maybe advice what is the best method to update existing .SHP files rather than creating new ones from scratch using the procedure that you have provided in attachment?

I thank you in advance for your help

Valon.

[nhopton]

Hi Vallon,

I only mentioned the tutorial to illustrate a way of tracing objects in Google Earth. With QGIS you'd be better off tracing the points, lines and polygons in GE and saving them as KML. Garvan mentioned above that QGIS can import KML files and I'm sure this is a much more efficient way of doing things. Use the plugin 'OGR Converter' to convert from KML to SHP, load the shape file into QGIS and then set the coordinate reference system (under 'Project properties') to which ever system you use in Kosovo.

Shape files don't have any information about how the shapes they contain should be represented on the screen in QGIS, you have to decide this. Right-click on the file name in 'Layers', select 'Properties' then 'Symbology' and then pick a line colour, line width, fill colour, et cetera.

You could display your old shape files in QGIS and then add new layers traced from GE to them.

To any of the experts, does what I have written above look about right?

Regards, N.

[FiReSTaRT]

Valon, I think the main issue is in defining the datum and the projection. The CRS used in former Yugoslavia was fairly exotic, and I wouldn't be surprised if the shapefiles for the Kosovo province will need a custom CRS definition. Here is the link to the article that outlines all of the parameters that you will need: http://pedja.supurovic.net/datum-i-proj ... ih-karata/. Since I have mostly been working with more common systems, I wouldn't know where to begin on how to do it in Quantum or ESRI for that matter.

Edit: Once you're done with your OSD, by editing the attribute tables, you will be able to change their attributes and display the lines based on the attributes (like an ordinal scale for road category).

[Jhelebrant]

Maybe this could be helpful for you:

gMapMaker

gMapMaker enables you to make OziExplorer compatible maps (image + calibration file) and giant merged images from Google Map tiles (satellite, hybrid, driving, terrain maps)
http://damiendebin.net/archives/gMapMaker/

http://www.mgmaps.com/cache/

http://forum.mgmaps.com/viewtopic.php?t=1116

[mickeyy]

How many places can I pin on Google Earth? I have Google Earth, and I have been happily pinning places I've been to and read about. I have about 170 pins, and now Google is not accepting any more pins. Is there a limit? And how do I get rid of the limit?