The geoid is defined as the more smoothed representation of the Earth and is described as the surface that would be assumed by the undisturbed surface of the sea. Therefore water surface is following the geopotential surface and by that we have the common understanding that water surfaces follow the curvature of Earth. Topographic surface is measured with different surveying methods all based on the assumption of the WGS84 model.
Through our previous experimental attempts at Lake Balaton we have found inconsistency with the curvature of the geoid model and we assume that the theoretical calculation of curvature on the surface of large bodies of water is non-existent. We are researching whether Lake Balaton has a geopotential surface anomally or all water surfaces are non uniform with the geoid surface.
In order to achieve a long distance curvature measurement on water surface a Terrestrial Laser Targeting (TLT) method is used. Super Accurate Laser Aiming Device (SALAD) and high precision collimation of 0.08mRad laser device are developed. Through analyzing the error source models of curvature testing, optical configuration of the testing devices have been optimized. Several target distances, in different ambient conditions at different locations have been tested. Environment readings are referenced and calculated to reduce the errors caused by the ambient conditions.
The required accuracy depends on the needed deliverable output. Accuracy refers to how closely a measurement or observation comes to measure a true or established value, since measurements and observations are always subject to errors.
Through the above processes, the relative accuracy of the measurements are meeting the experiment design requirement. The TLT method used in the experiments has high accuracy and practical advantages.
The general objective of this research is to evaluate and compare the results of TLT measurements over the surface of the lake with the calculation of the geoid curvature to determine the shape of the lake surface.
Our secondary objective is to study the effects of terrestrial refraction in different ambient conditions, at very low incidence angles close to the Non Uniform Density Transition Zone (NUDTZ) above the surface of the lake.
After many months of planning and preparation FECORE Inc. has conducted successful curvature and light refraction experiments at Lake Balaton from February 21-27, 2018
The high powered laser devices and the cutting edge collimators (focusing devices) have been custom built for this experiment.
The purpose of the week-long series of experiments was to determine if Lake Balaton is flat or convex due to the curvature of the Earth. While all bodies of water are presumed to be convex, because of the shape of the Earth, this assumption goes against our measurements and observations at the lake.
We had arranged to use a hotel in Balatonvilágos which was closed for the winter. This hotel is in the optimum position to have a sight to the most of the lake.
FECORE’s goal was to sight the laser up to 66 km (41 miles), but the adverse weather caused significant visibility issues and equipment problems. The team was forced to warm its custom built collimated laser to get it into optimal operating range. The first day, the laser crystal was fractured because of the heat required to warm up the device, but the FECORE team pressed on with a laser with more power but without the proper collimation.
The FECORE experiments were also conducted to study how light refraction is affected by measurable and observable weather conditions, such as temperature and humidity.
During a two-day window of clearer weather, the team accomplished the Hungarian record using a hand held blue laser.
The Hungarian Records Official associated with Guinness, certified an FECORE laser test at 7.7 km (4.78 miles) from a laser height of 1.5m (4.9 feet), which set the Hungarian record.
The FECORE laser tests provided evidence that the water surface on the lake is flat, because at 12km distance, with a laser height of 2.2 meters, the laser beam should’ve been hidden by the Earth’s curvature. Instead, it was observed and recorded at a 1.5 meter height.
On the 26th of February we had the high powered green laser four floors up in the hotel (in Europe ground floor +3 floors) so about 12 meters high. The blue laser was at 2.2 meters above the lake mounted on the SALAD.
The wind was strong, ambient air temperature was down to -11°C and the lake was at 0° C or below. At one location there were large chunks of ice and slush covering the moving water. At other locations the entire surface was frozen.
We went to the 12 km location at Siofok and we saw the green laser. It was very exciting to see it directly in our eyes and see it reflecting off the person next to us.
The blue laser beam was seen and photographed at 1.5 meters above the lake. According to curved water surface model the lowest ray of the beam should have been blocked 3.5 meters above the lake by a convex water surface. It was not, with some refraction upwards the beam extended down below any possible curvature.
After the 12 km observation success we headed for the 21 and 23 km locations. The weather was getting worse with wind, fog and water vapor condensated into ice crystals. We could not see the laser anymore to make other observations, so we decided to termitate the experiment.
We had two successful measurement attempts on the 12 km distance on two different days. They were fully documented by the film crew and will be released for viewing shortly.
FECORE project full report with all data, calculations and documentation is accessible here: