Sandor Szekely

Dear all! I have made the presentation to the Hungarian Geological and Geodezical Institute, and we have aggreed to make a cooperation on the upcoming Balaton lake and over land laser curvature measurements! We are now applying for director approval and then setup the first measurement on the lake. https://www.mfgi.hu/en/node/456 We will show our plan for the experiment after it has been properly designed and animated so we can discuss the hints and tipps before the measurement is done. 1) This should start with a standard aims and objectives statement. The aim of the experiment is to measure the curvature of water surface at the lake Balaton. 2) Then provide an estimate of the expected range of measurement values and accuracies required so suitable equipment and experimental methods can be devised. We are aiming to take measurements from 10km up to 77kms on the lake surface. Detailed description will include all measurement calculations and experimental methods. 3) Offer a system of control or reference points, established to a higher standard than the survey itself and preferably established by a different method, independent of the survey measurement technique. We are aiming to fixed objects on shore in different heights as planned. 4) Provide a proper method statement for the survey itself. This is not yet ready. I'd like to add one comment to the lake: the Balaton does not have an all time functional outflow, because it is blocked and opened only once in a few years.

I don't have a degree in math, but I get along well I worked as a cameraman long time ago and became an inventor 2 decades ago. I get along with technical English, but I am thankfull if you correct me! I use dictionary to search terms that I am not familiar with, but I may use them incorrecty. "the combined addition for curvature and refraction" thanks this makes it perfectly clearly understandable I'd like to calculate the amount of curvature that we are looking for, so we know what precision we have to do in our measurements. I see that it would be very hard to determine the difference of few centimeters on these distances, but looking for meters of difference should be very well measurable.

I have a confusion here: your chart says 4.9kms is 1.68 meter the curvature of earth in the 4.9 kms distance is 1.88 meter. so is the refraction here 0.2 meter or 1.68? "I do not intend protracted discussion about refraction here since it small in your case and largely irrelevant." in the case of 0.2 meter, maybe but I still don't see how it can be standardised as it deends on the local condition change. "One interesting point is that the variation of refraction with the frequency of the EDM leads to a phenomenon called dispersion which allows accurate measurement of the refraction over the whole observed line of sight with polychromatic light. Monochromatic sources do not allow this but special two colour laser systems such as 'Georan' are available to exploit this." Please tell me more abut this, I think this is exactly what I figured out with the dual colour laser too. So as I understand there are eqiupment like this? "Your objective is to measure the actual shape in space of the surface of the lake, is it not? You should be aware that the surface of water bodies on Earth is rarely level, flat, equipotential etc." My objective is to find out the shape of the water surface, if it is flat or curved. I think there is a huge difference in the outcome of the 2 models already at a shorter distance of 10kms, and a huge difference on the 77kms of the lake. This should be significant enough to exclude one of the models. I am not aiming to make the most precise measurement just to the accuracy that we can determine the shape of the surface: is it flat or curved? Is it possible to have 465 meters drop of curvature on the lake Balaton? Yeah maybe some Bull's blood would be good for me but I never drink alcohol

We will use a board big enough to capture the whole beam in the upcoming experiment. Way more easy than to get the same size of any detector. temperature is such that de My question is : how can anyone estimate, or use a standard value for terresterial refraction? Refraction is caused by change in ambient conditions like pressure, temperature, density or humidity (...) In the case of atmospheric refraction, light coming from thousands of miles from vacuum through more dense, humid, warmer and pressured air it has a well definable "standard" value. Change is more-less the same. But in the case of terresterial refraction like in our experiment the laser beam is going within a short height difference above water, conditions are nearly the same all the way. In this case the refraction can not be pre-determined as it depends on local changes. Refraction is also not a curve but a bend at certain points (where conditions change) and connected with straight path of light. So in my opinion terresterial refraction can only be measured, but not calculated with a standard formula. What is your opinion on the best way to measure it? (mine is to use different colours, but we did not have the collimator for the 2nd)

Hello Studiot I've been sick for the last days therefore had a lot of reading on the refraction subject. Please note here at end of page 26 "Assuming 17 levelling setups along a levelling line of 1 km, the total systematic devia¬ tion caused by refraction is 0.75 mm/km. For comparison: the standard deviation of height differences obtained by precise levelling using digital levels is about 0.3 to 0.4 mm/km (double run levelling) as reported, e.g., in [iNGENSAND. 1995J. There¬ fore, the refraction influences should be taken into consideration." "In order to obtain a hypothesis-free reduction of refraction influences, it is necessary to determine the refraction influences integrally along the propagation path" Summary of page 29 http://e-collection.library.ethz.ch/eserv/eth:23778/eth-23778-02.pdf Please explain in your referenced table what is the 2nd column and what it is it measured in? (meter?) In general I think terresterial refraction can not be calculated with a formula, especially not correspondent to the earth curvature. In other words: refraction has nothing to do with curvature. In my opinion terresterial refraction can be measured but not calculated, as terresterial refraction is due to LOCAL changes. Unlike atmospheric refraction where the ambient data can be estimated and the change of conditions are more alike. Refraction is bending the light due to CHANGE of the medium. I see no constant or presumable change on horizontal distance measurement. It is not like sunshine coming from near vacuum and entering into more dense, humidand warmer atmosphere - where we can estimate the effects roughly. Terresterial refraction is caused by LOCAL changes and temperature/ pressure differences, like a hot spot. That is a bending point of the laser, but NOT a continous curve at all. At the moment I see that refraction may be measured with different color of laser beams, and it can not be estimated nor calculated. so we have to look for theautoconvective laps rate condition: In my opinion the laser beam is going in a straight line between the bending points, therefore that is not a curve. The suggested laser beam refraction is 1/7th of the curvature in this example on this page (or the horizon distance is +7%) http://mathscinotes.com/2013/08/distance-to-the-horizon-assuming-refraction/ here some interesting data on convective stability http://meteorologytraining.tpub.com/14312/css/14312_53.htm Kalynos, I am a cameraman... a ccd is a device that has lenses and other stuff too.. that is called the camera. All sensors have optics.

Opps, whitch one I forgot to answer? I've not watched the video. I did fear this might be the case. You can get "bright" spots off of thr beam path, and you'll be killed by any beam divergence or laser wobble. I don't really think this experiment is within the reach of a hobbyist. Although it looks simple as soon as you start actually thinking about it there are so many subtleties that will make your results meaningless. so I should answer: no I can't get "bright spots" off the beam path. "killed by" what is that term? "Although it looks simple as soon as you start actually thinking about it there are so many subtleties that will make your results meaningless." what does this sentence mean? you say surface can't be measured with laser? well... this is your opinion and I have mine That's a terrible way to measure. You could do something similar with a camera sensor but where you measure the intensity from each pixel. But you'd need a large area CMOS or ccd and some clever way of removing ambient light. IS that a terrible way? LOL have you seen Stephen Hawking Genious video (attached here before)? my favourite part: But you'd need a large area CMOS or ccd a digital camera IS MADE OF A CCD please point me to your important suggestion, it looks like I did not find it

I think your calculation is far off from reality. PLease explain that excel with words too: you suggest, that at c37 6000meters: beam diameter is 11.75 meter? you say, that the calculated bottom of the beam is at -2.97 (meter?) How is that possible? then it should be visible on the board and it shall hit the water NONE of that is recorded... Please clear your calculations. your calculation is way wrong starting with a false assumption on the leveling. C1 - C4 is NOT measurement points. How do you come to this divergence calculation anyway? do you realize that the beam was reflected from the metal frame and therefore it spreads the beam? "This beam is spreading at an increasing rate of divergence rather than some fixed divergence angle. " how did you come to that conclusion? I think your calculation on beam divergence is way wrong

Michael you are wrong. Read through the lidar experiment again, Balaton lake DOES NOT flow like a river. It is a "trully level surface". " It has a level +150.55 at inflow (left on the picture) and 149.65 at outflow, a difference of 90cm from level." Very wrong and missleading.. NO the highest point of the lake is NOT at the inflow, and the lowest point is NOT at the outflow. (just to tell you for a less "misspresentation of the lidar experiment" I have been banned from an other forum... amm... just to inform You all: the RIVER Danube has a 26 cms drop over the COMPLETE route in Hungary. You say seriously that the lake has 3x more on a distance of 1/10? lol As a moderator I think you should be concerned to avoid discussions like this from the forum: "I suppose so it's just there to catch attention to YouTube video, to earn money on advertisements from Google. Scientists seeking for the truth don't behave like that. " IS this personal or has to do with the experiment evaluation?!

Hello Mordred We did think about using dual colour laser (and used it on the pre-test) to calculate reftraction by the difference of the blue / green beam. The cons are not a problem, indeed I'd like to add more types of equipments to improve the measurement accuracy. Actually we have only one problem with this: we have only 1 collimator that is on the green laser. We might be able to get an other one too. Could you please explain this in greater details? "The above may work better if the two lasers were aimed to a common point. Forming two sides of our triangle, this can help in leveling and distance from emitter calcs. (KEY NOTE do not mount the two lasers onto the same mount backboard. We don't want to add material expansion/contraction problems)" no, wedo not have laser scanner (mirrors) in this laser unit. As I pointed out, the horizontal vibrating effect was due to the laser beam hitting the water surface at the 3rd measurement (reflexion) I think there is a confusion on the meaning of "level". Here are some definitions, copy Nr1 here: "Level \Lev"el\ (l[e^]v"[e^]l), a. 1. Even; flat; having no part higher than another; having, or conforming to, the curvature which belongs to the undisturbed liquid parts of the earth's surface; as, a level field; level ground; the level surface of a pond or lake. [1913 Webster]" http://onlinedictionary.datasegment.com/word/level+surface Okay so you have NOT watched the video? then what are we arguing about? "not within the reach of hobbist"... come on.. please be more serious in commenting the experiment! Sensei, I did not answer this post because I found it unrelevant and unpolite. you asked for it so I'll answer. "And honestly must say, you spend the more time flying helicopter and playing volleyball than thinking and preparing for gathering data during the experiment. what is this very first sentence? I'm usually not replying to intriques... helicopter was supposed to enter the measurement, but we had to cancel that due to the storm. On the 3rd (THIRD) day we made some test flights for the upcoming measurement over land. We did not play volleyball... that is a videoclip from someone else... OMG... this is like facebook... I am here for scientific debate - I'll leave all coments like this unanswered in the future. About the size and position of the board : I answered that already, so I will not repeat my self - look back in the comments here. I am sorry, if you have not seen the GoPro mounted camera on the board... 4k is not need Captain WAS doing just fine job. I see you have no idea about a real measurement... I see you still do not understand that WE DID NOT USE the tape measure... it was at the leveling process and NOT the measurements. I am bored to answer questions like this... NEVER EVER AGAIN COMMENT ON MY BELIEFS! AND NEVER EVER mention like "It will obviously put you in "crackpot zone"" I give respect to people here and I DO WNAT THE SAME. If it starts to be like the other forum I will leave you too... "I suppose so it's just there to catch attention to YouTube video, to earn money on advertisements from Google. Scientists seeking for the truth don't behave like that. " REPEAT AGAIN: NEVER EVER TALK TO ME LIKE THAT! I AM NOT YOUR FRIEN, NOR A PARTNER. I AM GOING TO IGNORE YOU FROM NOW.

I will share - and cooperate - with scienceforum on the experiment setup and methodology as I think this is in the interest of my university partner as well. We (Zack, Steve, me) would like to have an open source measurement and a cooperation in the evaluation too - that is the reason I have the post here on scienceforum (ONLY) and let me share with you a PBS production : Genius with Stephen Hawking. The very first part of the film starts with a laser measurement and a boat. There is absolutely no scientific approach in this film - just a mainstream TV production - as they have not given any parameters or real measurements. You might like to check this film to understand better our motives to make a correct scientific approach to the question of curvature on water surface. https://www.youtube.com/watch?v=oNZOh4SUWUc

right 1. on the methodology I think it would be good to combine different techniques. I noted suggestion on various leveling equippments already, please advise how these different techniques can be used simultainosly to improve accuracy and exclude systematic errors from the measurement. Like how could a theodolite (possibly more in different positions) help to measure the laser beam height (maybe divergence too)? In this case of multiple theodolite laser height measurement we could make the measurements at the very same time (not like the boat 2.5 hours). Please share suggestion on this or any other possible method. What is your opinion on measureing on the frozen lake surface? (theodolites can be placed on the surface. refraction at night time or day time? is any posiible duct?) 2. human error will be best reduced with the help from professional geodezysts 3. instrument error may be reduced using multiple techniques?

Thank You MrMarker very well summarized. "As I see it, the experiment was a POC and what Sandor is trying to do here, coming to this forum, is getting ideas and suggestions on how to get it right the next time." Exactly I am here for this reason, and I am very pleased with the REAL scientific approach from most of You here! I am reading through the comments (taking the notes ) and as well organizing the real scientific team and the new measurement. Excuse me that I comment less now - I am listening carefully to the comments and I "try to catch up" with the terms and the explanations. (my profession is a cameraman) Klaynos: "I've not watched the video. I did fear this might be the case. You can get "bright" spots off of thr beam path, and you'll be killed by any beam divergence or laser wobble. I don't really think this experiment is within the reach of a hobbyist. Although it looks simple as soon as you start actually thinking about it there are so many subtleties that will make your results meaningless. " Thanks for sharing your thoughts on refraction, I think this is the most important "uncertainity" factor of the experiment.

MrMaker, as I pointed out that this 3rd measurement at dawn (4AM to 6AM app.) was a very unusual. Later we foulnd out at modelling that our laer hit the water around 1500 meters from the shore. So this is not refraction, but reflexion! (I named the folder reflexion on the google drive not to make confusion with the other ones) we went off the corse of the laser path and missed the point where it was hitting the water, as we got back on track the beam was very low. In a short distance it was rising upwards and passed above our heads. From the Canon camera it looked like a huge refraction, but from the laser position it was fine. So the horizontal trembling laser was reflected on water surface and therefore did not have vertica movements (significant). I absolutely agree that beam distorsion is the key of the measurement precision. Scienceforum is my notepad I will discuss the subjects mentioned here from the forum directly with the Hungarian scientist too. Thank you for the very usefull and extensive information to all.

I aggree I will not look for that article of 0.4mm/km as it was probably not the same question we are discussing here. The 11mm volume seems reasonable to me. I only have a worry if the refraction can be estimated or not - as it varies very much in local conditions. The calculation of refraction on each measurement would be preferable as the measurement route is more than 2 hours. Conditions change a lot over time. "This is why I keep recommending obtaining the services/advice of a professional surveyor." Absolutely aggreed and I am taking that advice

Okay I give the definition for "we" used in the above text. WE as: Leader of the experiment: Sandor Szekely My partners in developing and evaluating the experiment: Zack M'rabbet (AutoCad and film), Steve Torrence (3D animation) Special guests on the experiment: Dave Moor and Nicu Buricu Laserist Mina (goldlaser.hu) and her employee Sandor Szemendri, the captain of theBoat and some other people. laser curvature experiments, as this was nr.2 as title of the video. We had a pre-test measurment 1 month before (video on the same channel) We will continue to make more measurments (improved with ideas from here as well) on the lake Balaton and over land also. EDIT here to make it more clear: This section above is "we". this next section is the theoretical expansion of the "we" in the future: We will more likely work together with a university - if that cooperation agreement is signed I will proudly present it. I have spoken with the leader of the LIDAR experiment 2 days ago - as I heard that he had been disinformed. (He is not even working at the same university as I am in contact with.) He told me that he will send me the complete (open access) database of the very same route LIDAR measurement as we had in our experiment. I will share for evaluation here as soon as I have them. As his office is located near the site of the experiment he said he might be able to visit us on the next upcoming experiment. We always announce our experimental dates and locations and we WELCOME everybody who has the possibility to visit us.

yes I undertand that the light we see gives an apparent image and not the real position of the object. this caught my attention: "assuming no change in refraction" this is what I am pointing out, that refraction is not a constant but a continuocly changing index (? not sure about the correct term here) so we can evaluate a picture at an exact moment (with sufficien ambient data) but we can not use this momentary refraction as a constant in terresterial refraction calculation. Here I'd like to ask a question about a semi - related subject. (refraction) The sun is not where we see it: we see an apparent sun and the only observer who sees the real sun has it 90 degrees overhead. I'd like to attach a picture here, but I am restricted on any attachments to my comment! - why is that? Is there a formula to correct for the sun true position from the specific observer positions angle? I read about the reciprocal leveling in your attached image. This would be a good idea but the boat is not a stable position so we can't like shoot a laser backwards to position A. We tried this and we had a "backwards hit", but this is not a stable position so it takes time to get a direct hit. I'd like to add pictures to this as well, but I can not... this makes explanation quite hard. My question: Is there a triangulation leveling method, that uses multiple positions to get the most accurate height reading on the object? As here was suggested before too, I am going to use different methods in the upcoming experiment. I could place a theodolite in a different position than A, let's say like from a side view on the island there. (picture would be great here too...) Do you have any setup in mind that would make the measurement more precise with using different techniques in different positions as well?

SNAPHAT behave your self! and prove if you have such a claim! This is my only and last comment about METABUNK I am not going to answer anybody who does not respect me (I am disappointed to see the metabunk and fb trolls showing up here too) "You were banned for lying about being in contact with the folks from the 2013 LIDAR experiment you referenced in your OP here" NOPE I have been banned for trolling! (how can I troll on my thread? hmm) WHY I can not upload any files / pictures here? AM I restricted? (just like at meta...) I HAVE NEVER SAID ANYWHERE THAT I AM IN CONTACT WITH THE PEOPLE WHO MADE THE 2013 LIDAR EXPERIMENT! (INDEED I said I will not give my contact details until I have not signed the cooperation agreement) "misrepresenting their experiment;" DID I ? exactly where? this is a lie too "Mick contacted the lead author and the author said he had no contact with you" YES! Mick from metabunk DID contact him and made me a BIG SHAME! I spoke with Andras Zlinszky SINCE THEN! and cleared the missunderstanding that MICK MADE CONFUSION! I think he did this on puprose. MICK LIED to me : he said he did not ask about me, just the experiment : it's a LIE! SO to make it clear for you and other people reading this: I never said I am in contact with Andras Zlinszky. I have not even knew about the LIDAR experiment until GivemeClouds (as I remember) shared this document! I spoke with Andras 2 days ago, when I realized that Mick was contacting hi to make confusion. I AM in contact with university in Hungary since I said so - BUT I WILL NOT GIVE ANY DETAILS OR MY CONTACTS I think you can understand it after that creepy move from MICK WEST) "Your OP here similarly misrepresents/misleads regarding the authors' work seemingly as if you were involved," QUOTE HERE where exactly I said I am INVOLVED in the LIDAR experiment? THESE ARE SERIOUS CHARGES ON ME! I'd like the moderator to decide and give opinion : if this is a normal conversation style here from Snapshot, than sorry I will NOT be able to participate in such a debate "Misrepresentation of other authors' work is extremely troubling and academically dishonest."

I will answer the above posts in the morning, thanks for sharing the thoughts! I found a way to present the videos here - I uploaded them to my google drive and share the path here https://drive.google.com/open?id=0B2gyF12ygRBjT1NVYmMzREplTEU Here is the "Balaton laser reflexion" folder This was the experiment at dawn, when the laser hit the water surface at around 1500 meters from the shore. As I checked now this was the very same measurement where we had the horizontal vibration of the beam: so the solution is that the water surface was reflecting it like a vibration. Good to know that laser vibration points to reflexion problem. The name of the files contain the date and time stamp (Samsung videos and pictures that contain GPS as well) The "famous" picture from the Canon 650d 1200mm (400x2x1.6crop) teleobjective. First it was obvious that we see a huge refraction, but than we found that it is only the distorsion of the teleobjective lenses. In reality it was a straight line hitting the water at a 0.016 degrees (yube film at 6:35) angle that we did not notice on board. 4:51:50 picture shows the beam 4:52:29 video shows the laser beam before hitting the water - note how collimated is the beam before hitting the water. 5:00:24 picture shows the beam on the board with some distorsion - note that here the beam is already reflected on the water surface (GPS pos on the pic) 5:00:34 video shows the beam on the board looking like an amoeba - this is the effect of water reflextion 5:06:46 picture with GPS 5:07:13 video shows the vibrating laser beam reflected on the surface (that is why it is horizontal) 5:10:34 video shows some more laser beam swinging 5:10:58 picture GPS 5:29:57 video is showing the way back. The beam is not a direct hit at longer distances but from closer we can see the direct beam again. I include moere pictures, as well RAW picture files from the Canon for these pictures here I write the exact time of photo taken - note how interesting that the pictures are nearly taken at the same time from slightly different distances from the laser at position A. some pictures show a straight line while others are curved DSCN 1897 at 4:08:10 DSCN 1898 at 4:08:30 DSCN 1899 at 4:09:00 DSCN 1900 at 4:09:40 DSCN 1904 at 4:10:28 DSCN 1905 at 4:10:44 DSCN 1906 at 4:11:16 DSCN 1907 at 4:11:30 DSCN 1908 at 4:11:58 DSCN 1953 at 4:54:26 Sunrise DSCN 1971 Sun with clouds DSCN 1980 at 4:58:18 Boat arrives back to position A I am interested on your comments on this 3rd measurement. The laser was at 50cms 4.1 feet above water, the air temp was very cold like 16C. this is the animated 1200mm teleobjective perspective How can I measure the height of this ducting zone? Or to what humidity % level should I look for? I have a concern how I can make accurate environmental measurements at each point. Do I have a fast way to determine the values quickly? The distance of 10kms takes about 1.5 hur in one way + the measurement stops - this might extend the timeframe very much. Is there a datalogger precise, all functions included and fast enough? Please advise I'd like to collect more data too, you are right it makes the measurement more precise and understandable "I would recommend on your backboard you have reference grid lines both horizontal and vertical." This is correct, we'll do so Agreed with all points 1 to 4 this is a very good idea - I haven't made now but important "a detailed list or error margins on critical data points."

I 'd like to make the curvature experiment perfect, that would probably take a few more attempts but I am very persistent in my works Thanks for sharing the ideas to improve the measurements! I am about to sign a cooperation agreement with the top geodezist and geophysics in Hungary and I will point them to this forum to review the suggested ideas. "Regarding the board, I wouldn't use a semi-transparent material anymore." "Regarding the board, I wouldn't use a semi-transparent material anymore. I have only one concern: that the camera from the starting position is probably not going to be able to capture the beam on the boar all the way (we plan to do 10kms next time). In this case we can have a camera on the opposite shore, but that will not see the laser hit if the board is not transparent. We might as well use a camera in a boat that is following the measurement boat from the side.We will have a camera onboard facing the board to make the exact readings, but we can confirm the position only with timecode (that may not be well proved). We have to check now in a test if an opal surface or a retroreflective surface (like a moviescreen) is better to capture the beam. Please tell me your opinion on all this. About the movement of the laser beam: it was noticed only at the measurements upto midnight. The beam was moving ONLY sideways! It looked like someone was moving it on purpose, an unusually high horizontal vibration: quite high frequency and movement. I would like to attach a video here but I can't - can someone give me an idea how to? What could be the purpose of the only sideway movement? (at this time the laser was at 50cms 4.1 feet) We will definitely put the laser higher next time and use a big enough board to measure the beam. Bigger boat is not a problem, we can have powerboat, or a sailing boat with engine. The sail is a huge but not an ideal recording surface (in no wind conditions of course). The beam dispersion can be automatically validated if the board is functioning well. The board would be the best indicator for refraction as well. Water and air temperature measurements are quite hard to accomplish with the moving boat. I am not sure how we can make that accurate. Perpendicular and measured board (the height of the board may be varied here to match the exact height from water surface - the exact height is still a question so it is 1.5 on the picture for now)

Please model the beam size on the boat clip. I explained that it is not possible to have 2 meter of the laser at the bottom of the beam, because that would make the beam like 10 meters diameter. Make a drawing that shows that the beam is 2 meters at the 1.8 meter height and it is not extending to the white board, and the beam center is at 3.4 meters. This is not possible. on the 118.5 cms / 132 cms debate I attached a video that was deleted from meta. Zack clearly explains the math with autocad: the beam should be at 3.19 meters (instead of the 4.32 meters) That makes marginal difference in the outcome as the beam was recorded at 1.8 m - still a huge 1.4 m difference here I lost all the huge sript I made so far so I have to rewrite it again. does this usually happen on the website? no saved copy I attach here a picture: the first hit of the loop and the last direct hit of the loop. My question: if the beam was spread out to more meters as you suggest, how come that the beam is not seen on the retroreflective surface few inches below, but only in the camera lenses? I have explained that NONE of the measurements were taken with the tape. At C1, C2 and C3 leveling process Dave used a tape to tell my laserist a number to calculate the increment of raising the laser. It has nothing to do with the measurements! Dave could as well say only "raise up". We have explained in 2 video already that the photoshop measurements are inaccurate. I can not upload them here. Admin - any suggestions? 1st video: explaining the GE and FE calculated expected beam height. The 3.19 meters beam center is still not possible on the GE model. 2nd video: presenting on a real capture of a box why the picture can not be evaluated like Mick did. Your calculation on the board height from angle is inaccurate. "There is very good reason here to believe that this mark was placed incorrectly. That throws everything else about your calculations off." So you believe in something that throws my calcualtion off... " Assertions do not make the data reliable." Please provide me your unrefutable datat that shows that my divergence was not as I said with the 0.08 mRad collimator. Unless you make a model of beam divergence that is coherent with the photo evidences, your claim is only an opinion. Check the above pictures and my concerns on your guess of beam divergence. I see no evidences supporting your argument, you have not even modeled it if it possible. Please refrain from comments like "I know that's painful to hear" You are telling your opinion, do not make it look like you are the teacher here... I lost a lot of script here on the explanation of the terresterial refraction. so I conclude here: You wrote: "But refraction doesn't require some kind of dynamic 'change' to make it happen. Everything could be entirely stable." this is wrong, refraction is caused by CHANGE in the medium light travels through: In a constant density, pressure , temperature medium there is no refraction - only retardation. atmospheric refraction is a near constant value depending on the sun angles as sunlight coming from near vacuum and entering more dense, humid, and warmer air with more pressure and CO2 this should be - but not - taken into account when measureing the sun shadow lenght terresterial refraction can not be calculated like this as local conditions effect the outcome very much. A local turbulance or a mirrage effect can never be calculated like this, so this calcualtor is wrong. How come, that we make a good understandable definition of what we experience: the NUDTZ non uniform density transition zone - and it is criticized. How come you suggest a calculator without any references to it's accuracy? I think this calculator is deceptive - I ask other people here not to take that into concideration. Especially terresterial refraction is impossible to calculate like that on the many different aspects of modifying properties. Standard refraction used in geodezical terrain measurements is 0.4 millimeter / kilometer. Dubble run leveling in 1999 by Swiss authors I have to look for that link) "In order to obtain a hypothesis-free reduction of refraction influences, it is necessary to determine the refraction influences integrally along the propagation path. In the scope of this research work, the evaluation of the measured signal only is assumed to provide a satisfying estimation of the refraction influences. This estimation is based on image processing techniques which use the image data from built-in geodetic image sensors. Additionally, to estimate the refraction influences, the image processing techniques must be combined" http://e-collection.library.ethz.ch/eserv/eth:23778/eth-23778-02.pdf please read section 7 on the laser refraction experiment. your comments on the avarage amount of refraction and the refraction calculator are wrong. I agree with you that the pixel calculation is not an exact measurement. the best way is to mark all the sublines on the board too. In my measurements this gives some inaccuracy over long distance. in Mick's calculation it gives a greater difference. Of course AutoCad can calculate the lenght of an arc Yes I think the ducting made some strange effects like the beam swinging sideways horizontally in our measurements from sunset to midnight as the laser was at 50cms (4.1 feet). This effect was not so much at the 4AM measurement this effect was reduced, no horizontal swinging of the laser beam. We agree that the best timing is after sunrise when all temperature parameters are similar. We agree that raising the laser to higher position reduces this problem, we thought of raising the laser to 3 meters. After sunset the water until the morning is very calm, low or no waves and low wind factor (on the 16th of Aug).

We did do approximation on the refraction at different times of the day that is how we came to the conclusion to do the experiments at night time and dawn. It is very hard to model (actually impossible) to model the terresterial refraction as it is due to change in small local conditions. Like for example a turbulence is not possible to aviod if present. We should try to define the best possible timing. As daytime has more changes in ambient conditions (more sunlight energy, wind factor) and we can see mirage only at daytime and laser is not well seen in daylight: I figured out that this is not the good time for the laser test. Thank you for posting some examples so we can evaluate the data for the best possible timing of the measurement.

Hello Darkstar I don't agree with your assumption that the laser beam is spread out like 2 meters at that distance in the boat loop video. The laser center height should be over 3 meters so therefore that slice of the circle - that is 2 meters wide - would suggest a huge laser beam like 10 meters. In this case we would see the laser hitting the board too, but it is not. SO I think that the 1200mm optics is tricking us here. WE have no error at the slope correction laser leveling. Mick was wrong and instead of admitting it he banned me from metabunk (for "trolling"). We proved in the autocad video that his 118.5 cms leveling theory will result a 3.19 meters beam height instead of the 3.45 meters (not a significant difference). I answered to Mick's comments until I was not kicked from meta. I will not answer them again, as you copy pasted them here, PLS copy paste my answers too. Thanks for sharing the meta calculator, but I am banned from meta. (reason: I am trolling... can someone explain me how I can be trolling on my own thread?) so Mick case is closed, I am not debating with him. (unless he is here) 3) the reflective patch and camera lens glints are pretty much self explanatory as being invalid. I don't see them invalid. the refraction calculator is a joke... refraction is DUE to CHANGE. so how can we estimate a "standard" constant change? where can I put : time of the day, temperatures, humidity values and so on into that calculator? what is the change here? only distance? this calculator was made to give the near same value as curvature. but this is not how terresterial refraction is calculated. The sun is not where we see it, we see an apparent sun (exept when the sun is directly 90 degrees above us) - that is a huge atmospheric refraction. That is constant due to atmosphere conditions. But the terresterial refraction caused by local differences that curve light, it can not be calcualted with that calculator... Cool if you are trying your self too! Please share your findings, and as well your difficulties with making such an experiment, like leveling with this accuracy. I forgot to write that you can get pretty good collimators cheap for hand held lasers too, that is much more important than the power of the unit. We have discussed the safety aspects of the laser with my laserist well ahead of the experiments. As this it was used as a 3W version it was safe to look into with the naked eye from over a kilometer distance. Actually we tried the sunglasses but at night time let's say it is impossible to wear in a boat. A camera CCD is more sensitive to the laser beam but none of the cameras had any problem eighter. We used green and blue dual lasers at the pre-test but we had collimator only for the green now. It would be good to use the blue to see the refraction (as the 2 colours have different refraction). Our laserist and the Goldlaser company we work with is the biggest Hungarian outdoor laser show (and laser theater). They do events every week and well aware of the safety aspects. We named the zone that we non uniform density (that is the water vapour above the lake surface) transition zone (meaning the zone - height above the surface) I see this is the best explanation to what we experience. why do you think it is invalid? "far too many systematic errors" is not someting I can argue about, pls nem that you think is not accurate and pls define your point how much it effects our outcome. I don't like this: Mick said this already at meta... first of all I can not see those posts, second the opposion claims should be explained here not referenced. Mordred, please explain more about refraction conditions that could have occured at the experiment. (or anyone who is expert in refraction) This is an interesting thought " I can't find a combination that has a refractive curve upward from the Earths surface." I assume that with inverted conditions from day to night the direction of refraction should change too. Of course there are many other factors to consider too. But this would really suprise me that refraction is always curving downwards. Actually I am not sure if there is a possiblity to gather all ambient data - like we should measure the temp / hum factor all the way too. So I think we should find at least the best possible timing of the experiment. We have to concider that a strong sunlight makes the laser invisible. Please share advices on timing and weather conditions to look for in the upcoming experiment.

1. Thanks that is my intention! 2. Yeah I did find the beast possible geodezists and geophysisists to work with (not "she" but all "him"). I will name my partners after we have signed our cooperation agreement. 3. I love that laser and we are improving it. We will have a much finer increment adjusting of the beam and as well we will calibrate it in a longer distance. 4- We will surely use geodezy equipments in the next experiment with professional stuff. 5.-7. I am thankfull if you write your ideas of the proper or best possible method of making the measurements. We will model and make real test of the best ones. 8. Thank you again! I am commited to find the truth. 9. Time is an illusion (think about the one hour you spend at the dentist - or your loved ones) I am answering in time order (to the comments I can) but this comment caught my eye. "Bizarre. That would make the beam go left & right, " that is exactly what happened in our 2nd experiment! It was before midnight, and the beam was like waving left to right in a very noticable amount viewing from the boat. I even called the laserist on the shore if they are moving the laser? she said of course not the laser is not touched. The effect was exactly as you described it - a huge (like 10 meters) swing looking at the beam from the boat. We saw this effect at the midnight measurement only. Yes, I would also say : "bizarre" Well let's start with the board. It is plastic with 0.5 cm inner square tubing (sold in Praktiker garden shops) I am not sure this is a good solution for the board as it leads the lights internally well so the beam looks bigger. Next time I would use a normal plastic sheet or a retroreflective material - not sure what would be the best. Our opinion is that the beam was not spreading out very much over the long distance. Here I attach my comparison on the beam divergence at 2 distances. Fine calibration of the laser beam can be an issue, next time we do it on longer distance. (it was now calibrated on about 100 meters distance) "With a 0.08mRad, at 5.038m distance, the spot diameter would be around 44cm." this could be realistic in my opinion. "But at 400m, it looked like the spot was already at 20cm, so at 5km distance I would estimate it to be 205cm, or 2.05m." Then the beam center would be about 1 meter (radius) so the beam should be visible at a height of minimum 2.45 meters (3.45 - 1). The beam was recorded at 1.7 meters so it is still a big difference (0.75 meter). I think our beam was well collimated. The motion gif picture is a high speed very distorted image (1200mm optics) that shows the reflexion in the camera lens when we are pointing it directly into the laser. here I attach the corresponding dat, C18 at the last row: Balaton-laser-exp-816-data-sheet-4th-measurement final.pdf

Studiot "All the flight paths were along the edge." Correct, this was confirmed by the leader of the LIDAR experiment today. I will get soon the flight path measurement data on the exact same route as our boat measurement. I will share for review. I fully agree with everything else you wrote here.

Dear Stuiot and the other members I am sorry I have not been here for a day, I will catch up now with the comments and answer them. I am researching the GE vs FE theory since years now but here I would like to focus on the lake curvature experiment in the thread. "Sandor's results, if the survey was properly conducted, will be correct. The water surface departs from following the Earth's curvature; it is essentially flat." our 16th of august experiment was the first measurement we have done so far with the laser so it has some things to reconsider and make better in the upcoming measurements. We will work toghether with a Hungarian university on the study so the results will be more precise and definite too. Studiot, I have learned about the bottom of the lake from your information here! Sorry, for your question at post #6 I have to gather information from the university as well. "How can the water surface not be as flat as the ground on which it is resting? This is not support for the flat earth view, just modern science sorting the fact from the fiction and properly acknowledging real facts." This shall be our motto for the thread! Exactly right question Hello Mr Marker I have uploaded all the measurement evaluation pictures here: https://drive.google.com/drive/folders/0B2gyF12ygRBjU0NSSmIxbXU4bVk so you can check them individually and see how I marked the laser hits. We had laser direct hits on the reflective jacket and as well in the camera optics too. The collimator on the laser beam is 0.08 mRad in our measurements. Studiot, please note: our collimator was 0.08 mRad this time (on the longest range measurement it will be probably 0.003 mRad) and I say we need an accuracy of 0.001 degrees for laser leveling.