جستجوی مقالات مرتبط با کلیدواژه "satellite data" در نشریات گروه "فیزیک"

Nowadays, one of the essential needs of human societies is the need for energy. Our country has also turned to new sources of energy supplies, i.e., the establishment of nuclear power plants in the direction of industrialization and energy supply. In this research we are reporting the discovery of radioactive elements in the western part of Kerman province. The study area is located at 160 km southwest of Kerman and 40 km north of Sirjan. This range is longitudinal, 55° 30' 00'' - 56° 00' 00'' eastern and 55° 30' 00'' - 56° 00' 00'' north latitude in 100,000 sheet of Pariz geological map. In this study, various methods such as mixture tuned matched filtering (MTMF), and orthogonal subspace projection (OSP) were applied for the process of the remote sensing data, and single-variable methods were also used to process the radiometric data. The results have indicated the high potential of the Sentinel 2 in showing the alterations associated with the uranium deposits. Also, due to the geology of the area and the alteration holes and the cross-sectional study of the mixture tuned matched filtering regulation, the MTMF method has been able to show the argillic alteration in the Sentinel 2. According to the geology of the area, these images have the proper potential to separate sandstones and silica gravel from other units. Finally, the promising areas for radioactive elements were identified and preserved. Also, due to the process validation, the previous field surveys from the area were also investigated, and the presence of high levels of radioactive elements in the area was confirmed.

Reliable and sufficient information of 10-m wind and temperature fields over open seas and near coastlines is a necessary and important data that has impact on many marine activities. Assimilation of NWP models can be used to assess an estimation of these fields. This study reports the performance of the weather research and forecasting (WRF) model to hindcast 10-mwind and temperature fields that were evaluated under two different physical options of planetary boundary layer (PBL) and surface layer (SL) for an area over the Gulf of Oman and the Arabian Sea. The case study includes 16 simulations of 8 different days from WRF model version 3.7.1. The WRF model is configured with two nests. Parent nest has 0.3 degree and the inner nest has 0.1 degree horizontal grid resolution. The grid spacing of the inner domain is almost 11-km. The Lat-Lon (latitude-longitude) method is used as the map projection method. For all domains and all runs 39 terrain following vertical levels are set. The validation of the simulated fields is done considering two observational datasets (the weather stations for 10-m wind and 2-m temperature and satellite instruments just for 10-m wind). Near-surface observations of 2-m temperature and 10-m wind speed and direction are collected from 55 weather stations, located within the chosen area. The measurements from satellite instruments have become an important source of data in the regions that in-situ observations are sparse like seas and oceans, hence observations from two different scatterometers (ASCAT and OSCAT) are also used to evaluate 10-m wind simulations. Moreover, in order to better understand the model performance for different choices of the physical schemes, sensitivity of the model has been investigated. There is plenty of choices for the combination of parameterization schemes available for WRF model; for the current study two configurations are taken from other’s previous published research works. The physical parameterization that used in this study are Revised MM5 and Monin-Obukhov for surface layer and MRF and MYJ for planetary boundary layer. These choices are used to create two different configurations called Phys1 and Phys2. Comparison between winds from satellite scatterometer and simulated winds show very little difference and hence good agreement with observations. Acceptable accuracy has been obtained from statistical analyses. These analyses demonstrate that the maximum average RMSE of wind field is 2.39 m/s, based on results of comparing with ASCAT data and it is 2.37 m/s, based on results of comparing with OSCAT data. The analyses also show that simulation of wind fields have better results over offshore regions than coastlines weather stations. The outcome shows that the simulated 10-m ‎wind‎ present acceptable general skills over the sea. The validation of 2-m temperature presents that the model has a proper estimation about temperature field over the coasts and near coastal station within the simulation domain. The maximum average RMSE of temperature field is 2.6 degrees of centigrade. Finally, without any justification to run WRF for longer periods from a quantitative and qualitative assessment of the results, it can be concluded that for the WRF model has an acceptable performance to simulate 10-m wind and 2-m temperature over the Gulf of Oman and the Arabian Sea. It should be noted that to verify these results for longer periods more similar experiments must be tested.