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Chinese Chang'e-3 was launched on 2nd December 2013, and it has successfully landed on the moon. The rover was successfully deployed from the lander, and touched the lunar surface on 14 December. One of the payloads on board the Chang'e-3 rover is the Lunar ground-Penetrating Radar (LPR), aimed at observing the lunar subsurface geology at frequency channels of 60MHz and 500MHz. The LPR has worked...
Atmospheric disturbance can strongly influence the accuracy of Ground-Based synthetic aperture radar differential interferometry (GB-InSAR). In this paper, a comparison of different techniques for compensating the atmospheric artifacts in Ground-Based SAR is presented. The way the fluctuation of atmospheric parameters like temperature, pressure and humidity among successive scans affects interferometric...
Subsurface exploration of the Moon by an orbiting HF radar is reported. Lunar Radar Sounder (LRS) is an FMCW radar which was installed on a lunar exploration platform of Japan, Kaguya, in 2007. LRS operated in a frequency range of 4–6 MHz. A 30 m long dipole antenna was used as the transmitting/receiving antenna. A weighting function was applied to the transmitting pulse waveform so as to suppress...
The martian shallow crust has been studied through two subsurface sounding radars, MARSIS and SHARAD which operate at 3–5 and 20 MHz, respectively. The capability of radar to resolve the subsurface structures and the stratigraphy relates both on the radar features and the electromagnetic parameters of the shallow crust. For small grain size sediments, like clay minerals, the dielectric properties...
A Lunar Penetrating Radar (LPR) based on time domain Ultra Wide Band (UWB) technique is currently within the scope of China's Chang-E 3 (CE-3) lunar mission, with the purpose of studying the subsurface structure of the Moon. Exploring the UWB microwave radiation and transfer properties of lunar regolith and establishing a reasonable inverse model are essential for the estimation of the thickness of...
The need for more effective road condition management policies and practices has been growing rapidly over the last few years. A key word in this development is “focus” and for that more accurate and reliable continuous NDT survey methods, such as GPR, are needed. In asphalt thickness surveys a problem has been how to calculate/estimate the dielectric value of the asphalt. Thus far this has been done...
Fracture is an important geologic phenomenon which is crucial for petroleum and geothermal exploration and exists in various scale and geometry in nature. Borehole radar is an important tool which can image single fractures several to tens meters away from borehole in thousands of meters depth. However, the detectability of various fractures is not clear. We analyzed the radar response to a thin fracture...
An update on the development of a self-correcting method of calibrating pavement layer depths is presented. The approach is applied to multi-offset simulations of a forthcoming 3D noise-modulated ground penetrating radar (NM-GPR) system. The expected response of a series of wide angle reflection and refraction (WARR) datasets produced by this equipment is modelled for typical road pavement configurations...
GPR is a recommendable non-destructive technique for thickness measurement of pavement layers because data acquisition takes place at normal traffic speeds, making GPR a cost-effective technique. On the other hand, the large collected data, when the GPR system is mounted on a moving vehicle, is difficult to process. Given that processing is conducted by qualified practitioners, it is a key to obtain...
Deterioration on asphalt pavements is affected mainly by traffic and moisture. The traffic on road pavements is responsible by the occurrence of cracks that promotes the pavement deterioration. The moisture decreases the driving comfort and reduces the asphalt-aggregate bond leading to the degradation of the asphalt materials. Additionally, moisture, and especially the moisture inside the asphalt...
Time slices of very dense GPR measurements carried out at concrete with a real point distance of less than 10 mm in x and y direction show weak reflection patterns besides the strong reflections of reinforcements. A repetition of these measurements with the same local geometrical precision at the same specimen shows the same reflection pattern. We suppose that the heterogeneity of concrete given by...
The hydration reaction between water and cement governs both the rate of strength gain in fresh concrete and also the final strength of hardened concrete. These strength properties are typically assessed by casting small samples (often cubes) taken from the fresh concrete and conducting destructive strength tests at selected days after casting.
As a nondestructive method, GPR is widely used in detection the distribution of the broken rock zone surrounding laneways. For deep coal mining engineering, the rock surround laneways would experience several damages. The broken rock is a special composite medium by rock, fracture which is filled with water or air. Although, a lot of researches about the electromagnetism of rock have been done, mostly...
Due to complex subsurface situation, echo signals surveyed with Ground Penetration Radar (GPR) often contain a lot of clutters, including direct-coupling wave, random noises and multiples. Existence of these clutters submerges measured feature signals of rock structures with GPR, so suppression of them is often essential conduct for rock feature extraction. For extracting rockmass structure features...
In life detection with ultrawideband (UWB) radar, the high signal-to-noise ratio (SNR) is very important for good performance. In this paper, the m-sequence with a carrier is applied to life detection, and SNR can be improved by pulse compression and linear average. The hybrid sampling technique is used to improve the sampling resolution and reduce the cost. The peak-to-sidelobel ratio after pulse...
The reduction of “float” coal/rock dust contaminated with quartz along with toxic and radioactive metals must be minimized at its source, that is, at the rock/coal crushing cone directly under the bit-tip. Biochemical reduction and compaction concentrate the upper floodplain river mud-water load of toxic and radioactive metals into a thin coal layer adjacent to the seam boundary rock during the deltaic...
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