Topographic map for housebuilding plans

[SEANT]

Despite the closing of all matters related to measure and calc, I invested some effort so will post anyway.

 

The impression I’m getting from this “Bilateration” process is something like this. The attached is 2D only, but could accommodate a 3D elevation via the laser level and Pythagorean Theorem.

BiLat.zip

[Ferronovum]

look for "Pointset reconstruction"

Is this for the data points or?

 

Please use the quote button for replys so ppl and I can track what you are refering to.

 

Best Regards,

/Ferronovum

[Ferronovum]

Despite the closing of all matters related to measure and calc, I invested some effort so will post anyway.

 

The impression I’m getting from this “Bilateration” process is something like this. The attached is 2D only, but could accommodate a 3D elevation via the laser level and Pythagorean Theorem.

Well, thank you for your effort!!!

Ready solutions are welcome. Your formulas looks alot like mine but some differs and layout are different but hey, we don't share brain .

I also post my solution of "Bilateration" for public eye. The calculation cells are hidden so it looks nice. Just unhide for checking the formulas. I have made some notes so you can follow my thoughts in the calculations.

 

/Ferronovum

Bilateration.zip

[eldon]

its simply the one with the shortest distance that is the correct one.

 

That is one of the most foolish statements that you have made. To think that the shortest measurement MUST be correct is very dangerous.

Although measuring with a tape is low tech, there are still many sources of error that you must not ignore.

1. Misreading the tape.

2. Reading the tape correctly, but writing down the figures in the wrong order.

3. If someone else is writing down the figures, they do not hear correctly and write down the wrong figures.

4. Zero point of the tape is not at the correct place.

5. The tape is not straight.

6. The tape is not level.

7. The tape is not at the correct temperature.

8. The tape is not at the correct tension.

9. The tape is old, and has been stretched.

10. When entering the figures into a computer, the figures are entered in the wrong order, or are wrong.

There may be other sources of error, but all these can apply to any measurement.

 

I only signed off from surveying posting, because I thought that someone would chide me, but I cannot let a statement like that go unchallenged.

[Ferronovum]

That is one of the most foolish statements that you have made. To think that the shortest measurement MUST be correct is very dangerous.

Although measuring with a tape is low tech, there are still many sources of error that you must not ignore.

1. Misreading the tape.

2. Reading the tape correctly, but writing down the figures in the wrong order.

3. If someone else is writing down the figures, they do not hear correctly and write down the wrong figures.

4. Zero point of the tape is not at the correct place.

5. The tape is not straight.

6. The tape is not level.

7. The tape is not at the correct temperature.

8. The tape is not at the correct tension.

9. The tape is old, and has been stretched.

10. When entering the figures into a computer, the figures are entered in the wrong order, or are wrong.

There may be other sources of error, but all these can apply to any measurement.

 

I only signed off from surveying posting, because I thought that someone would chide me, but I cannot let a statement like that go unchallenged.

 

God I'm tired of this.....

As you self said, 1/2 mm on the map is like 100 mm in reality.

 

And by the way, my tape is like 50 years old, that must have some effect too!!! Its also made of steel, does that have any effect too? (yes, the temp makes a significant effect, I know that)

 

Take a look at the drawing, there you will see that even with some error in the measurement there is a significant difference in length between the intersections. And I did said that during some conditions there could be missreadings, especially when 3 or more points line up.

 

Do you got any more to complain about?

Bilateration.dwg

[eldon]

Do you got any more to complain about?

 

I am sure you will give me more ammunition

 

Just do not underestimate all facets of the job you intend to do. As you are starting with no knowledge, you have to be given advice on everything to make a proper job.

[Ferronovum]

I am sure you will give me more ammunition

 

Just do not underestimate all facets of the job you intend to do. As you are starting with no knowledge, you have to be given advice on everything to make a proper job.

 

Well I shall try to keep you posted during the the time

[rustysilo]

And for help getting x,y,z points imported just see my tips and tutorials link below (in signature) OR get the lisp from Jeffery P. Sanders as linked previously.

 

If you have x,y,z ascii point file then no need for xml.

[Ferronovum]

Time for an update.

I bowe for the experts. My plan of method fall out pretty bad. Seams like I didn't meassured enugh accurat with the tape. Was pretty stressed and dark outside so instead of -/+ 3 cm I got an aprox error around 1-2 meters in xy-plane. Z-error inatead got around +-2 cm.

The plan now is to skip everything with elevation and just use a flat map. Deadline is this weekend. Yikes...

[rustysilo]

Sorry to hear that. Hope it goes well from this point forward.

[eldon]

I can only admire your character for having a go. Perhaps next time, you will be perfect

[Ferronovum]

Well I had to try. Sadly it didn't went the way I hoped.

But I learnt some stuff:

Don't do it this way in the winter.

Have time.

Bring a laptop and add the number directly and check apperance if it looks good, otherwise, redo the meassure. Include angels.

Use a laser for distance too. I only had a waterlevel with laser for the elevation. Pretty nice when you light that up a dark winter evening. Very easy to read the level but hard to type it on paper.

Use a headlamp when its dark.

 

That's it for now.