Suppose we assume that crop circles are made my human beings working at night. Suppose further that they are using GPS devices to guide them. Do GPS readings have any characteristic errors that would show up in the patterns?

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"Never let the task you are trying to accomplish distract you from the study of computers."

Commercial (less expensive) GPSRs typically have an error range of up to 10 meters. It makes Geocaching interesting. More expensive models that use extra satellites have smaller error ranges. The problem is that the error range drifts. One time it might be to the NW, another to the south.

Typically, you can make a decent crop circle with pegs, ropes, and boards. Add some planning and pre-build diagramming, and you're golden.

Fred

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"For shame, gentlemen, pack your evidence a little better against another time."
-- John Dryden, "The Vindication of The Duke of Guise" 1684

Are you talking about absolute or relative errors? If we are talking about the location of of two points relative to each other ( and not about their absolute location relative to coordinates on the earth) does the relative location have a 10m std. error? In addition to my curiosity about crop circles, I'm thinking of getting a GPS unit to help plan the grading of my yard.

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"Never let the task you are trying to accomplish distract you from the study of computers."

Absolute error.

With an absolute error of +/-10m for each of two points, the theoretical relative error in their separation is +/-20m. But in practical terms, if you measure the location of both points at the same time, or at times very close to each other, I think the error in separation would be close to 0m. (You'd get the same error in both measurements, so you could ignore it for your landscaping purposes).

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Search for ‘differential GPS explained’ on Google. The 10 meter error is the absolute error the relative error is less than 1 meter. And if you do your work in a short amount of time; without a major change in atmosphere you would probably have a relative error of less than 30 cm.

There is nothing I know of in the GPS system that would end up giving you some kind of pattern.

As far as using a GPS to create crop circles; it would be a major task. As Nowhere Man say’s; some rope, pegs, boards and a good plan would be faster and easier.

Jim

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Have you noticed that Polish and Russian crop circles are rather small, simple, and crude?

http://www.hufos.net/images/polish_crop_circle.jpg

http://www.rense.com/general66/PolishCrop8Jun05.jpg

http://www.nationalufocenter.com/art...july06_001.jpg

http://news.bbc.co.uk/2/hi/world/mon...rts/804079.stm

Why are only the best and most artistic “aliens” making crop circles in England, while less talented “aliens” are making crop circles in Poland and Russia??

I agree that England has the most intricate crop circles. But the Russians are supposed to be good at mathematics and geometry. What would explain the difference except access to some technology? Or do these circles appear in remote areas where people have less education?

Another thing I wonder (it doesn't seem to warrant starting another thread) is if there is some chemical that could be sprayed on the ground so that the circle would form quickly but a day or two after the spraying. That would make the phenomenon look even more mysterious.

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"Never let the task you are trying to accomplish distract you from the study of computers."

My understanding is that a lot of the imprecision in consumer GPS units is due to random signal delays caused by density and thickness variations in the earth's atmosphere. Many of the more sophisticated GPS units (even my little old Garmin Summit) allow you to subscribe to a local radio service that broadcasts a steady stream of "correction factor" information based on the local atmospheric conditions in real time. More than five years ago, when I was living in the UK, I listened to a documentary on Radio 4 where they were managing to get imprecision of only a centimetre or two using this system. The correction information was being broadcast on a sub-carrier of Classic FM.

clop

I'd say none of the above. They just haven't been at it as long so the art is not as developed. The technology for circles is not advanced, just ropes and boards as mentioned above. It's practice that makes perfect.

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Cum catapultae proscribeantur tum soli proscripti catapultas habeant.

As Trebuchet said, it's still a young art form in those countries.

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‘To those who regard “crime fiction” as some sacred icon which must follow a rigid formula, I will always be the man who writes 18-syllable haiku.’Trying to make sense of computers, The Error Log.

Far more likely they're using anchor points and ropes.

Far more accurate with respect to the anchor point than a GPS.

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If I set the budget, we'd have Ares and more. Unfortunately, I don't set the budget, and Ares is just too expensive and too far out for us to accomplish our goals within the budget we were given.

If we halt the ISS, all versions of Ares, and transport Orion and Altair aboard DIRECTv3's Jupiter family of Shuttle-Derived Launch Vehicles, we just might make it back to the Moon by 2020.

I've had the experience of laying out driveways using old fashioned optical surveying equipment and it's not easy to do this in the daylight. I suppose with GPS and computerized equipment that it's an easier job nowadays. I think it would be a difficult job to establish the relative location of the centers of circles and endpoints of lines at night. It's certainly not impossible to do it with strings, but if you've ever done such work in daytime, you realize how much tramping around it takes. It's much more efficient to have an device like a transit that can accurately measure angles.

Saying that people create crop circles with boards and strings is like saying that people build automobile engines with metal and grinders. It could be true, but it doesn't really explain how it's done. The boards-and-strings theory needs elaboration. One possibility is that the layout is done with GPS and other modern technology. Another possibility is that that certain landmark points are put down days before the crop circle is completed, so the work goes quickly. Another possibility is that the design of the circle incorporates certain nice geometric coincidences that makes laying it out easy.

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"Never let the task you are trying to accomplish distract you from the study of computers."

Boards and strings is not "just a theory". It's been demonstrated for the cameras multiple times, including by the guys who created most of the earlier circles, some of them extremely elaborate, in the UK.

You're making this much more complicated than it really is. No surveying equipment, GPS, or aliens are involved.

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Cum catapultae proscribeantur tum soli proscripti catapultas habeant.

I would be interested to know how they established the correct points for the centers of circles and the end points of lines. Is everything referenced from a central axis?

I'm not familiar with the crops and planting methods in Britain. If I must walk through the crop to establish a reference points, is it easy not to accidentally tramp down places that one wishes not to damage?

If new technology is available, why wouldn't the crop circlers use it? Is this like a sport where there are certain informal regulations on what equipment is allowed?

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"Never let the task you are trying to accomplish distract you from the study of computers."

If you stop and think about it, using a rope and a board is much faster than walking a few feet, looking at your GPS, shifting a half step back, checking again, then stomp, then move in the direction you think you need to go, then realize, oops, a step to far that way, better upright that area of crops... oh crap, lost a satellite, now my fix is only good within 3 feet....

A board and a rope is way simpler and faster, at least for certain abstract geometric designs...

Now, if you wanted to make a specific picture, then a GPS could help you, I suppose.

CJSF

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Two years ago moved from my town
I was looking up past the city lights
But the city lights got in my way

See the constellation ride across the sky
No cigar, no lady on his arm
Just a guy made of dots and lines

-from "See The Constellation"
by They Might Be Giants

Again, you are making it too complicated. There's no "correct" point for the center of the circle, you just walk out into the field, pick a spot, and drive in a stake. The radius of the basic circle can be determined by the length of the rope you happened to bring with you. Once you've laid that out, you can easily start by dividing the circle into six sectors using the same rope and begin making patterns from there. New technology isn't used because there's no need.

Crops are pretty resilient. The circle makers have to mash them down pretty firmly with the board to get them to stay bent. It's not difficult to walk through a field without leaving major traces, especially if you follow the lines left by the tractor tires.

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Cum catapultae proscribeantur tum soli proscripti catapultas habeant.

I understand that once the center of a circle is established, a rope can be used to walk a given arc about the center. Once two ends of a line are know, a rope can be used to define the line. Those procedures are used in ordinary surveying work using tape measures ("chains") instead of ropes. The relative location of the reference points (centers and endpoints) to each other is main problem. I agree that crop circles do not have to bear any relation to existing features such as the roads, fences, pipes etc. that are part of the design of driveways and roads. The designs do have certain symmetries and this imposes some constraints on them.

If I think of laying out crop circles as complicated, at least I'm doing it from the perspective of having done surveying field work myself. I haven't heard a convincing explanation yet about why making crop circles is so simple. I understand that there could be situations where the design is a spontaneous artistic creation. This could happen if the workers can be directed from some vantage point that can see the design. I understand that with a low crop, the reference points could be set using an ordinary surveying transit since you have line-of-sight to places that you want to drive a stake. However, thinking about how I would do it in a tall crop and without some direction from an observer, I would use modern equipment like a GPS unit and a programmable calculator. Store the reference points in some coordinate system and when you get to the field, convert the coordinates to the location that you select.

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"Never let the task you are trying to accomplish distract you from the study of computers."

Disclaimer: Not suggesting anyone should actually do this. The point of the post is to demystify the simple prank that is "crop circles" (as the indications are).

It is simpler than surveying 3D terrain with a surveyor's integrity at stake.

The hardest part of making crop circles is coming up with an interesting pattern. Once you have that,

*- Draw it using the CAD software of your choice.

*- Select any arbitrary 2 pioints A & B noting the distance in between

*- dimension all critical points of the design/pattern from these 2 points using aligned (not orthogonal [i.e. not x,y]) dimensions. This will give you the distance of all the critical points directly to each of the two points A & B (two dimensions per point)

*- Find a flat piece of a field

*- Take any point as A

*- Measure the distance AB at any direction to Mark point B

*- Recreate/Mark all critical points measuring with two tape-measures/threads/chains/ropes pinpointing them at crossing points of the measured distances. If point C is 2 meters from A and 10 meters from B, then stretch a 2 meter thread from A and 10 meter thread from B and Mark C when both threads are stretched straight and when you are on the right side of the AB line.

*- then use a board attached to a rope to flatten the field in the desired pattern.

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"They reasoned that an object situated at the center and related equally to the extremes in every direction can have no impulse to move in any specific direction. In fact, they compared the situation of such an object with that of a man violently but equally hungry and thirsty, standing at the same distance from food and drink and unable to decide in which direction to move." - Aristotle

As a pure geometry exercise, I agree with your method if the crops are low lying crops and you can walk through them without tramping them down in places that you don't want the flattened. A modern transit would be much simpler to use in that case since you can locate points from the reference line by angle and range. In your method, if crop is tall then you'll have to lift your ropes above them with poles. GPS would be less awkward to use.

Another question is how you label the reference points. I know that once a surveyor gets ten or so stakes on the ground, things get confusing. You forget which stake is which. They have to be labeled carefully. In crop circle making, I suppose they must all be pulled up afterward - not a requirement in surveys. You can try only staking out a few things at one time, but that will also get confusing unless you have an observer who can tell you if you forgot to do something.

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"Never let the task you are trying to accomplish distract you from the study of computers."

You're joking, right? You do realize man-made crop circles predate GPS deployment by several decades...

Not necessary.

Bingo, and with a single length of rope, at that. Fully capable of bisecting angles, creating triangles, and subsequently smaller circles.

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If I set the budget, we'd have Ares and more. Unfortunately, I don't set the budget, and Ares is just too expensive and too far out for us to accomplish our goals within the budget we were given.

If we halt the ISS, all versions of Ares, and transport Orion and Altair aboard DIRECTv3's Jupiter family of Shuttle-Derived Launch Vehicles, we just might make it back to the Moon by 2020.

Does anyone know a way to contact the people known to have made crop circles without GPS? That might sort this out.

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Gillian

"Now everyone was giving her that kind of look UFOlogists get when they suddenly say, 'Hey, if you shade your eyes you can see it is just a flock of geese after all.'"

"You can't erase icing."

"I can't believe it doesn't work! I found it on the internet, man!"

How to make a crop circle
How to make a crop circle - with pictures
circlemakers.org
That was about 5 seconds of Googling.

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At night the stars put on a show for free (Carole King)

One Earth, One Sky - IYA 2009
All moderation in purple

I skimmed through the thread, but sorry if I missed this:

Has anyone mentioned that the phenomenon of crop circles, even complex ones, very much predates the practical availability of personal GPS devices?

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I'm like one of those idiot savants...well, except for the savant part.
"In order to increase awareness of the homeless, security have been given binoculars."

The chronological argument doesn't convince me that modern crop circlers disdain GPS. The circles have grown more complicated haven't they?


I'll certainly repsect the opinion of anyone who has actually tried to lay out a set of reference points with a rope and done the same job with GPS. ( I agree that it's easier to tramp down a circular arc with a board anchored by a rope to a stake than it is to read a GPS while you walk with a board - I'm talking about setting reference points like the center of the circles and points marking where a circular arc begins and ends.)

The fact the geometric constructions can be done with a rope doesn't convince me that this is a simpler way to do things than with GPS. I've done work with 200 ft tapes and it isn't simple to maneuver these around in the daytime. How long are the crop circlers ropes?

A interesting question is whether the rope must be help above the crop or whether you can let it drag on the ground as you maneuver it.

In addition to talking about ropes, I would like to hear someone explain why they think using GPS would be complicated. Suppose you have a reference point that is 250 ft from a known point A and 300 ft from a known point B. Which is going to be simpler: Have one person walk to that point with a GPS meter? Or have four people mainpulate two ropes and have the people with the free ends of the rope pull the ropes taut while they walk toward each other?

A still unanswered question (for me) is whether the complicated crop circles of Britain are always done in low crops. When I think of USA crops, I think of a cornfield. You can get lost in a cornfield in the middle of the day. How would you use a rope in such a field? Hold it up with poles?

No one has made a cultural/educational argument agaist GPS. To me, that argument would be more plausible than saying GPS is too complicated. You could argue that ropes are traditional or that the people who supervise crop circle constructions are unfamiliar with new fangled technology.




.

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"Never let the task you are trying to accomplish distract you from the study of computers."

Well, since they first appeared, yes. But not since the introduction of GPS units; instead, they've gotten more complicated since people got better at making them. You can look things up, really, which you clearly haven't. There have been exceedingly complex circles for at least twenty years and probably far longer.

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Gillian

"Now everyone was giving her that kind of look UFOlogists get when they suddenly say, 'Hey, if you shade your eyes you can see it is just a flock of geese after all.'"

"You can't erase icing."

"I can't believe it doesn't work! I found it on the internet, man!"

tashirosgt,
Just out of curiousity, why is this such a big question for you? My impression is that no one here has actually made a crop circle, so we are not going to debate the experimental details of how best to make one. Why does it matter so much if some/all/any/none are made with or without GPS?

Maybe the people circlemakers.org (link above) would be able to give you more details.

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At night the stars put on a show for free (Carole King)

One Earth, One Sky - IYA 2009
All moderation in purple

Thanks for explaning a bit more of your thinking, tashirosgt. I will agree with you that for the planning of some crop circles, a GPS might help. I still don't think it is necessary for very complex circles, but that doesn't mean some people wouldn't use GPS to get things set up.

CJSF

__________________
Two years ago moved from my town
I was looking up past the city lights
But the city lights got in my way

See the constellation ride across the sky
No cigar, no lady on his arm
Just a guy made of dots and lines

-from "See The Constellation"
by They Might Be Giants

It doesn't matter much to me how people make crop circles.

What? I'm only supposed to talk about things of vital importance?

I suppose how people make crop circles has about as much practical significance as the "magesteria of science" or the other threads. The thing that stimulated my interest in the last few posts is trying to figure out whether the people advocating the simplicity of the board and ropes method really have any practical experience in laying out figures in the field. Or are they just ivory tower theorists, armchair geometers, etc. - visions that stimulate me to argue with them. They might be entirely correct that ropes and boards are easier (and they might be secret crop circle makers). I'd like to understand why ropes and boards are superior to GPS.

I think this depends on rather specific details. How high is the crop. Can you drag the ropes over the ground? What is the relative accuracy of GPS? The only article that I've read about making a complicated crop circle with boards and ropes said that it was done in the daytime over two days. It didn't convince me that using boards and ropes was simple. Since the author refered to the participating crop circle making group as if it were well known and established, it did suggest to me that the tools of the trade might be influenced by tradition.

Another way to understand my motivation: I've stopped watching television entirely, so now I waste my time on the internet!

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"Never let the task you are trying to accomplish distract you from the study of computers."

Not at all. I'm busy wasting my time at work. If you really want a time waster, come over to Fun And Games!

I wasn't giving you a hard time. As I said, it might be helpful to talk with some of the actual practitioners of the art for a detailed insight.

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At night the stars put on a show for free (Carole King)

One Earth, One Sky - IYA 2009
All moderation in purple

I think what people are trying to tell you, is that the creation of crop circles has been documented, and the best documented crop circle makers have used ropes and boards. Whether or not GPS would be easier, faster or more precise is irrelevant to that fact.

Do some crop cirlce makers use GPS? Probably. Which is better? Who knows? It probably depends on the people doing it, what the design is, and, as you properly noted, what type of crop.

Some reasons for why boards are better?

1. Low tech - less prone to fail
2. Stealth - no backlit screen lighting up the field
3. Less equipment - you'd still need a board and perhaps a rope even WITH GPS, depending on how you were making the pattern
4. Legacy - people have done this in this way for a long time, and you can find documentation on how to do it.

Does this mean I think there are no advantages to using GPS for crop circle making? Not at all. I can think of reasons why it would be a plus. I think for most crop circles, it just hasn't been necessary or that clear of an advantage to use GPS to make them. Perhaps that will change as more people are familiar and comfortable with GPS. Time will tell.

CJSF

__________________
Two years ago moved from my town
I was looking up past the city lights
But the city lights got in my way

See the constellation ride across the sky
No cigar, no lady on his arm
Just a guy made of dots and lines

-from "See The Constellation"
by They Might Be Giants