Can anyone point to a resource that lists the accuracy of measurements taken in Google Earth?
Apparently, the measurment ruler is not accurate over long distances > 5,000 km.
Google's offical stance says, "makes no claims as to the accuracy of the coordinates in Google Earth. These are provided for entertainment only and should not be used for any navigational or other purpose requiring any accuracy whatsoever".
In 2011 two brazilians published an article about it, and they concluded that:
*the error is just 0,44% for line measurements; *the error is just 3,54% for polygon measurements; *the error is just 1,39% for perimeters calculation;
Based on these results they concluded that you can use Google Earth as a good source for mapping in scales smaller than 1:150000, assuming the planimetrical error as 0,1 mm.
Of course this is just a case of study, and these results depend on your area of study. I suppose that in the US the results may be even better.
Source: Lopes, E. E.; Nogueira, R. E. Proposta Metodológica para validação de imagens de alta resolução do Google Earth para produção de mapas. In: Simpósio Brasileiro de Sensoriamento Remoto, 10, Curitiba, PR, 2011. Anais: São José dos Campos: INPE, 2011.
Source link (in portuguese): https://www.researchgate.net/profile/Ruth_Nogueira/publication/266032536_Proposta_Metodologica_para_Validacao_de_Imagens_de_Alta_Resolucao_do_Google_Earth_para_a_Producao_de_Mapas/links/54ff4e900cf2672e224563eb/Proposta-Metodologica-para-Validacao-de-Imagens-de-Alta-Resolucao-do-Google-Earth-para-a-Producao-de-Mapas.pdf
After just installing a break water and knowing all the dimensions, i checked it on google earth to see how close the eye in the sky is, on 470 ft it showed 477 ft, I tried google earth pro it did not make a difference. I have used it before and it seemed the accuracy was better. The location used was 48d38'59.33"N x 123d33'07.23"W The long leg of the east to west break water sections is accually 470'7" x 20' wide.
I have measured The University of Kentucky's Commonwealth Football Stadium in Lexington, Ky.
Goal Line to Goal line is supposed to be 100yds or 300'
Google had the distance, goal line to goal line up the hash-marks at Commonwealth at 299.09'. Off by .0030%.
Have measured base paths (90') at MLB stadiuons and found same degree of accuracy.
Google Earth with Landsat GeoCover scenes over a global sample of 436 control points located in 109 cities worldwide. Landsat GeoCover is an orthorectified product with known absolute positional accuracy of less than 50 meters root-mean-squared error (RMSE). Relative to Landsat GeoCover, the 436 Google Earth control points have a positional accuracy of 39.7 meters RMSE (error magnitudes range from 0.4 to 171.6 meters). The control points derived from satellite imagery have an accuracy of 22.8 meters RMSE, which is significantly more accurate than the 48 control-points based on aerial photography (41.3 meters RMSE; t-test p-value < 0.01). The accuracy of control points in more-developed countries is 24.1 meters RMSE, which is significantly more accurate than the control points in developing countries (44.4 meters RMSE; t-test p-value < 0.01). These findings indicate that Google Earth high-resolution imagery has a horizontal positional accuracy that is sufficient for assessing moderate-resolution remote sensing products across most of the world's peri-urban areas.