My lat/long points have an offset (2-3 meters) in both X and Y – about 2m SE in my region (-120.644,35.260) – from where the points used to be (unless my memory is failing.) I'm using Google Earth 7.1.
They (exactly lat/long points in GE) plot correctly on an OSM and other GE overlays. OSM shows the point in the correct place on the image but in GE the point appears offset to the SE. OSM streets also have the same offset.
All the historical layers are offset as well.
Has something happened in the last few months to caused GE to plot points incorrectly?
Best Answer
Aerial imagery from sources such as Google Earth have some horizontal positional accuracy problems. A 2013 paper from the Earth Institute at Columbia University showed that the Root Mean Square Error (RMSE) can be significant (8.2m for Google Maps in the study). The RMSE of horizontal accuracy appears to vary greatly between studies. Reasons for this may include different methodologies, different study areas/control points, and time between studies (Google Earth accuracy has become better over time).
More studies on the positional accuracy of Google Earth:
2014 paper in Artificial Satellites has a summary section of previous research on the topic
Page from the University of Cologne
2013 paper in the International Journal of Multidisciplinary Sciences and Engineering: "Positional Accuracy Testing of Google Earth"
Here are two similar answers: Google Earth, Google satellite, and Bing aerial accuracy
How accurate is the google maps latitude and longitude I am using?