Research Institute for Geodesy

Zdiby, Czech Republic

Research Institute for Geodesy

Zdiby, Czech Republic
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Klokocnik J.,Academy of Sciences of the Czech Republic | Kostelecky J.,Research Institute for Geodesy | Kostelecky J.,Czech Technical University | Novak P.,Research Institute for Geodesy | And 2 more authors.
Acta Geodynamica et Geomaterialia | Year: 2010

We have surveyed the Earth's surface using gravity anomalies and second-order radial derivatives of the disturbing gravitational potential computed from the gravitational model EGM2008 complete to degree and order 2159 (for selected degrees up to 2190). It corresponds to 5 arcmin resolution on the ground. Over most well known impact crater sites on the Earth we found the second-order derivatives (not available from ordinary gravity surveys) offered finer discrimination of circular features than the gravity anomalies themselves. We also discovered that some of the sites show evidence of double or multiple craters which will need further ground verification. Some of these signatures (in hilly or mountainous terrain) may also need to be corrected for the gravitational effect of topography to sharpen their hidden features.

Klokocnik J.,Academy of Sciences of the Czech Republic | Kostelecky J.,Research Institute for Geodesy | Kostelecky J.,Czech Technical University | Pesek I.,Czech Technical University | And 5 more authors.
Solid Earth | Year: 2010

In 2008 the new Earth Gravitational Model (EGM2008) was released. It contains a complete set of spherical harmonic coefficients of the Earth's gravitational potential (Stokes parameters) to degree 2190 and order 2159 and selected orders to degree 2190, that can be used for evaluation of various potential quantities with both the unprecedented accuracy and high spatial resolution. Two such quantities, the gravity anomaly and second-order radial derivative of the disturbing potential, were computed over selected areas with known impact craters. The displays of these derivatives for two such sites clearly show not only the strong circular-like features known to be associated with them but also other symmetrical structures which appear to make them multiple impact sites. At Popigai, Siberia, the series of circular features fall in a line from the "primary crater" in the southeast (SE) direction. At Chicxulub, Yucatán, there appears to be one more crater close to the "primary" in the northeast (NE) direction, as well as possibly others in the vicinity of the main crater (SW). Gravity information alone is not, however, proof of impact craters but it is useful in identifying candidate sites for further study, for examination by geologists and geophysicists. In the case of Chicxulub, a very recent single seismic profile suggests that a more likely explanation for the observed circular like gravity signal from EGM2008 NE of the "primary" is a pre-impact basin. © Author(s) 2010.

Charvatova I.,Academy of Sciences of the Czech Republic | Klokocnik J.,Academy of Sciences of the Czech Republic | Kolmas J.,Masaryk University | Kostelecky J.,Research Institute for Geodesy | Kostelecky J.,Czech Technical University
Studia Geophysica et Geodaetica | Year: 2011

Extant written records indicate that knowledge of an ancient type of compass in China is very old - dating back to before the Han dynasty (206 BC-220 AD) to at least the 4th century BC. Geomancy (feng shui) was practised for a long time (for millenia) and had a profound influence on the face of China's landscape and city plans. The tombs (pyramids) near the former Chinese capital cities of Xi'an and Luoyang (together with their suburban fields and roads) show strong spatial orientations, sometimes along a basic South-North axis (relative to the geographic pole), but usually with deviations of several degrees to the East or West. The use of the compass means that the needle was directed towards the actual magnetic pole at the time of construction, or last reconstruction, of the respective tomb. However the magnetic pole, relative to the nearly 'fixed' geographic pole, shifts significantly over time. By matching paleomagnetic observations with modeled paleomagnetic history we have identified the date of pyramid construction in central China with the orientation relative to the magnetic pole positions at the respective time of construction. As in Mesoamerica, where according to the Fuson hypothesis the Olmécs and Maya oriented their ceremonial buildings and pyramids using a compass even before the Chinese, here in central China the same technique may have been used. We found a good agreement of trends between the paleodeclinations observed from tomb aligments and the available global geomagnetic field model CALS7K. 2. © 2011 Institute of Geophysics of the ASCR, v.v.i.

Klokocnik J.,Academy of Sciences of the Czech Republic | Kostelecky J.,Research Institute for Geodesy
2nd International Conference on Advanced Geographic Information Systems, Applications, and Services, GEOProcessing 2010 | Year: 2010

Satellite imaging is well known as a useful tool in many scientific disciplines and various applications. Google Earth, with its free access, is now - thanks to increasing resolution and precision - such a tool. It improves the visualization and dissemination of scientific data, and opens doors to new discoveries. For example, many Nasca geoglyphs are now visible to Google Earth and so are the orientations of Chinese pyramids, which appear to be laid out with the aid of a magnetic compass. Google Earth can also "see" a previously unknown "Monte Alban II" close to the well known "Monte Alban" in the Valley of Oaxaca (Mexico), as well as prehistoric causeways in Mesoamerica (namely, in north Yucatan) and in the Chaco valley, New Mexico. We find that Google Earth can save time and resources significantly: before, during and after field measurements. © 2010 IEEE.

Bohm V.,Social Republic | Bohm B.,Social Republic | Klokocnik J.,Academy of Sciences of the Czech Republic | Vondrak J.,Academy of Sciences of the Czech Republic | Kostelecky J.,Research Institute for Geodesy
Serbian Astronomical Journal | Year: 2013

The relationship between Mayan and our calendar is expressed by a coefficient known as 'correlation' which is a number of days that we have to add to the Mayan Long Count date to get Julian Date used in astronomy. There is a surprisingly large uncertainty in the value of the correlation, yielding a shift between both calendars (and thus between the history of Maya and of our world) of typically several hundred years. There are more than 50 diverse values of the correlation, some of them derived from historical, other by astronomical data. We test here (among others) the well established Goodman-Martínez-Thompson correlation (GMT) based on historical data, and the Böhms' one (B&B) based on astronomical data decoded from the Dresden Codex (DC); this correlation differs by about +104 years from the GMT. In our previous works we used several astronomical phenomena as recorded in the DC for a check. We clearly demonstrated that (i) the GMT was not capable to predict these phenomena that really happened in nature and (ii) that the GMT predicts them on the days when they did not occur. The phenomena used till now in the test are, however, short-periodic and the test then may suffer from ambiguity. Therefore, we add long-periodic astronomical phenomena, decoded successfully from the DC, to the testing. These are (i) a synchrony of Venusian heliacal risings with the solar eclipses, (ii) a synchrony of Venus and Mars conjunctions with eclipses, (iii) conjunctions of Jupiter and Saturn repeated in a rare way, and (iv) a synchrony of synodic and sideric periods of Mercury with the tropical year. Based on our analysis, we find that the B&B correlation yields the best agreement with the astronomical phenomena observed by the Maya. Therefore, we recommend to reject the GMT and support the B&B correlation.

Hanzalova K.,Czech Technical University | Klokocnik J.,Academy of Sciences of the Czech Republic | Kostelecky J.,Research Institute for Geodesy
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives | Year: 2014

This paper deals about astronomical orientation of Incas objects in Ollantaytambo, which is located about 35 km southeast from Machu Picchu, about 40 km northwest from Cusco, and lies in the Urubamba valley. Everybody writing about Ollantaytambo, shoud read Protzen (1993). He devoted his monograph to description and interpretation of that locality. Book of Salazar and Salazar (2005) deals, among others, with the orientation of objects in Ollantaytambo with respect to the cardinal direction. Zawaski and Malville (2007) documented astronomical context of major monuments of nine sites in Peru, including Ollantaytambo. We tested astronomical orientation in these places and confirm or disprove hypothesis about purpose of Incas objects. For assessment orientation of objects we used our measurements and also satellite images on Google Earth and digital elevation model from ASTER. The satellite images used to approximate estimation of astronomical orientation. The digital elevation model is useful in the mountains, where we need the really horizon for a calculation of sunset and sunrise on specific days (solstices), which were for Incas people very important. By Incas is very famous that they worshiped the Sun. According to him they determined when to plant and when to harvest the crop. In this paper we focused on Temple of the Sun, also known the Wall of six monoliths. We tested which astronomical phenomenon is connected with this Temple. First, we tested winter solstice sunrise and the rides of the Pleiades for the epochs 2000, 1500 and 1000 A.D. According with our results the Temple isn't connected neither with winter solstice sunrise nor with the Pleiades. Then we tested also winter solstice sunset. We tried to use the line from an observation point near ruins of the Temple of Sun, to west-north, in direction to sunset. The astronomical azimuth from this point was about 5° less then we need. From this results we found, that is possible to find another observation point. By Salazar and Salazar (2005) we found observation point at the corner (east rectangle) of the pyramid by Pacaritanpu, down by the riverside. There is a line connecting the east rectangular "platform" at the river, going along the Inca road up to vicinity of the Temple of the Sun and then in the direction to the Inca face. Using a digital elevation model we found the astronomical azimuth, which is needed for confirm astronomical orientation of the Temple. So, finally we are able to demonstrate a possibility of the solar-solstice orientation in Ollantaytambo.

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