GOOGLE EARTH LIMITATIONS

GOOGLE EARTH LIMITATIONS.                       Google earth images does not come in high resolution although some technique can be employed to increase the resolution of the images. Such techniques includes and not limited to breaking the area of study into a well planed overlaying strip layers. This helps you download images with a small area that will be of a bit high resolution and this requires that for that given study you may have up to 30 image layers. Remember google earth images lacks spatial reference and this means that there is need to Georeference all these 30 image layers and thereafter you do image mosaic to merge all the 30 overlapping image layers. This is cumbersome to say the least and also introduces alot of errors. What are then the sources of errors here? Before downloading such images from google earth, you have control points you want to use for georeferencing (can be monument or landmarks you know their coordinates or you can choose those points on google earth and extract their coordinates) .These points while georeferencing, you may not be able to get the exact point having that coordinate in the images and this shift have introduced an error, imagine where such accumulates over those 30 image layers and see the error you have just in your georeferencing. This results to tilt in the image after georeferencing. When digitizing also, there may be some shadows on the structures as a result of low resolution data, and you may trace the shadow thinking it's the structure outline. This also a source of error. These and many more are the limitations of google earth images but fear not as am about to introduce you to amazing that can offer you much more and eliminates such limitations as observe in google earth imagery.