Question about Google Earth "elev" and perpendicular

[allenr]

I hope somebody with more Google Earth knowledge can help me.

Can I discover the low and high points of my land by looking at the "elev" "ft" number at the bottom - middle of the picture?

Oddly the higher ground seems to have a higher number, yet given that the "eye alt ft" number remains the same shouldn't the higher ground have a lesser number?

Or is the "elev ft" referring to elevation above sea level.

Is the elevation figure accurate enough to guide me as to where the start and end point of a drip hose of say 200m (660ft) should be to minimize the friction loss over that length?

And how can I know when I'm perpendicular (directly above ) my land?

 

[DANOCHEESE]

Google earth is not designed to be that accurate. The cheapest way to do this is with a transit. You can buy a simple one for less than $100 on ebait

Typical elevations are shot from a ref mark. Above sea level is a ref. Above or below the becnmark at the center of the propery. Then they are exspressed above or below.

 

[woodchuckie]

If you or someone you know has a good gps it will show elevations. I use an old fashion topo map. It has 20' elevation lines. Different areas show different lines.

 

[dmccarty]

Does your local or "federal" government have topographic maps?

Before this Internet thingy I used to get topographic maps for land I was looking to buy. They have elevation marked on the map. In the Internet Age my rural county has a GIS aka mapping office that is online. They show property lines, topographic maps and even areal photos overlayed on the property lines.

I know the UK made VERY accurate surveys decades/century ago. I think they were called ordinance surveys. Maybe the same happened in Australia.

Later,
Dan

 

[kwin]

You can do it with Google Earth with the add on to make it a topo map
below is my land
Sorry I see your down under so I don't know if it will work as mine is for the lower 48 states. They also call it Trail maker software for hiking.

 

[allenr]

Thanks guys, for the information.

I'll check into the options suggested.

Kwin, what do you mean by "Florida soon Texas?

 

[Gryantaylor]

I hope somebody with more Google Earth knowledge can help me.

Can I discover the low and high points of my land by looking at the "elev" "ft" number at the bottom - middle of the picture?

Oddly the higher ground seems to have a higher number, yet given that the "eye alt ft" number remains the same shouldn't the higher ground have a lesser number?

Or is the "elev ft" referring to elevation above sea level.

Is the elevation figure accurate enough to guide me as to where the start and end point of a drip hose of say 200m (660ft) should be to minimize the friction loss over that length?

And how can I know when I'm perpendicular (directly above ) my land?

The alt eye elevation is the elevation that your looking from (the airplane) and it doesn't change when you move the cursor around the screen. Teh elev ft (or meters) is generally ft above sea level depending on your settings. The alt eye elevation is also MSL but should not effect your search for high and low points.

P.S. I would have to agree with the other posters that google earth is great for a lot of stuff but it isn't always that precise. Its great to find the general area, or if something will generally work but I would definatally take additional measurments (gps, etc) before actually building something.

 

[CurlyDave]

I have a very good handheld GPS and it will only give about +/- 25 ft (say 8 m) on the best of days for elevation, and many days it is about twice that.

However, the best GPS units have a built in barometric altimeter which will be able to measure differences, which is what you are concerned with to about a meter, if you learn how to calibrate them.

Since you already have the line and a water source, with a transparent section at one end and a large reservoir at the other, you could easily make a water level, and measure differences in elevation to a few mm over 200 meters.

 

[allenr]

Since you already have the line and a water source, with a transparent section at one end and a large reservoir at the other, you could easily make a water level, and measure differences in elevation to a few mm over 200 meters.

Yes, I have done that in the past, very accurate, just looking for something quicker - and easier.

But to everybody, how do I now when I'm perpendicular (directly above) - and does that add to the inaccuracy of the elevation figure?

 

[allenr]

Does your local or "federal" government have topographic maps?

I know the UK made VERY accurate surveys decades/century ago. I think they were called ordinance surveys. Maybe the same happened in Australia.

Later,
Dan

Yes I believe we have all of the above, but the governments don't do anything for nothing!