However, if you just want to do a preliminary study of the site, in order to propose preliminary roads and drainage layouts, and you donвЂ™t have surveyor data ( because it is still in a very early stage), and all you need is just relative contour lines ( not absolute contour values) and topological features, then Google Elevation Import maybe a good choice because Topographic maps are already sufficient for this use.For neighbouring sites that donвЂ™t have the surveyor data, use your judgement whether you want to use Google Elevation data, bear in mind that you may or may not have LiDAR ( we donвЂ™t know, Google doesnвЂ™t disclose) level vertical accuracy.It is recommended that you donвЂ™t use Google Elevation Import if you have the surveyor data.Then, when to use/ not use the Google Elevation Import function? The accuracy would be significantly less. 8 years have passed, so now the data accuracy can only improved.ДЇor the places that Google doesnвЂ™t use LiDAR, SRTM ( or the interpolations) steps in. Unfortunately Google doesnвЂ™t want to disclose at where. We do know that Google doesnвЂ™t use surveyor data.Д«ut it should be noted that Google starts to use LiDAR since some 8 years ago, at some places, which gives it a vertical accuracy of 5~25cm error. So, where does Google Elevation stand?ДЄll we know is that Google uses multiple data sources, ranging from LiDAR to SRTM to some other unknown sources. The vertical accuracy can be in mm, depending on where you put the machinery. Without a doubt, surveyor data is the MOST ACCURATE of all, simply because the surveyors are there on the ground ( pun intended) to take the reading. LiDAR configured to see the ground C: Surveyor data In Malaysia, the vertical accuracy ( both absolute and relative) stands at between 6-9 m, as shown below: The accuracy of SRTM Data can range from 5 to 10 meter, depending on where you are. However, Google Earth improved the results by using (in house) interpolation algorithms to mix and mesh SRTM data with other data in order to derive accurate results for these area. The elevation datasets are affected by mountain and desert no-data areas, thus the results could be inaccurate if the voids are large or the voids are completely covering summit or ridge area. Two radar antennas were outfitted in order to capture the topographic data. In 2009, SRTM consisted of a specially modified radar system that flew on board the Space Shuttle Endeavour during the 11-day STS-99 mission. SRTM stands for Shuttle Radar Topography Mission. Naturally, the question is, how accurate is Google Earth Elevation import, and given the range of validity, what can we use it for?Д«efore we tackle this issue, we need to understand what are the different ways one can obtain elevation levels. MiTS 2 has a function called Google Earth Elevation Import, that allows you to read the elevation points directly from Google Earth, without relying on SurveyorвЂ™s input.

Import gpx into google maps