In this article we show that a single transparent wedge or a plate with a wedge part can be used as a very simple and useful interferometer with numerous applications. This interferometer permits to modulate phase distribution on interference fringes to evaluate quantitatively the parallelism of a light beam and aberration of a wavefront, to specify the spectral line shape in a wide range, to measure the light wavelength and refractive indices of solids and liquids. In addition, it provides suitable beams for holographic study of phase objects and fabrication of diffraction gratings.

. The radar interferometric technique is a powerful tool in estimating subsidence with accuracy within mm using phase observations. In this article, Sentinel 1A satellite data from 2017 to 2021 have been used in order to monitor the subsidence that happened in Mashhad. Also, Sentinel 2 images of 2020 were used to monitor rainfed and irrigated crops in the region. The results of the radar interferometric studies showed that during the statistical period, 44 cm of subsidence occurred in the studied area. Further, in order to find the cause of subsidence, the information of piezometric wells in the area was collected and their changes during the period of 1370-1398 were examined. The amount of subsidence recorded for each period was 6 cm for 2017-2018, 12 cm for 2018-2019, 15 cm for 2019-2020 and 11 cm for 2020-2021. According to the results, the underground water level in the areas with land subsidence has been accompanied by a drop. Especially in the villages of Mehdi Abad, Shahr Danesh, Mashhad Qoli, etc., which have the highest drop in the underground water level and are also in the risk zone of high subsidence. One of the main reasons for land subsidence in the study area is the excessive extraction of underground water resources.

Seismic Interferometry is the process of cross-correlating seismic traces recorded at different locations at the Earth's surface with the aim of retrieving information about the subsurface.The field of Interferometry changes our opinion about parts of seismic data that is usually discarded due to being considered as noise. Some examples of such noises are seismic codas (the multiply scattered parts of seismic waveforms) and background noise (whatever is recorded when no identifiable active source is emitting, and which is superimposed on all recorded data). In this study the efficiency of Interferometry is shown trough some examples.

Subsidence is a downward motion of ground surface with small horizontal displacement vector. It may happen due to natural factors or human activities. In Iran, subsidence may occurbecause of the human activities and excessive extractionof groundwater resources. In this study, we applied Synthetic aperture Radar Interferometry (InSAR) to investigate the rate of subsidence. We estimatedthe rate of subsidence in Khoramdareh plain using Permanent Scattering (PS) for the duration time 2003-2005. The mean velocity map indicated that the subsidence is occurring with the rate of 35 mm/yr in direction of Satellite Line of Sight. Afterward, we used Geospatial Information System (GIS) to evaluate the risks of subsidence. The results show some parts of the railways, main roads and highways are affected by subsidence.

Purpose: To evaluate the refractive outcome of silicone oil removal and intraocular lens (IOL) implantation using laser Interferometry. Methods: Thirteen silicone oil-filled eyes of twelve patients were included in the study. IOL power calculation was performed using laser Interferometry (IOL MasterTM V1.1, Carl Zeiss, Jena, Germany). All of these eyes underwent silicone oil removal and cataract extraction with IOL implantation. Post-operative refraction was evaluated. Results: The mean deviation of the final post-operative refraction (spherical equivalent) was -0.30±0.91 D (Range, -1.87 to +1.3) at 12 weeks. The mean axial length of the eyes was 22.99±0.84mm (range, 22.07 to 25.24 mm). No major complications occurred intra or post-operatively. Conclusion: Laser Interferometry appears to be a feasible and satisfactorily accurate method to calculate IOL power in some silicone oil-filled eyes. Further studies comparing this technique to others are warranted. .          

Among the different surface plasmon-based measurement techniques, the detection of phase of surface plasmon is one of the most accurate and sensitive methods. The phase can be measured accurately in different interference based techniques. In this study, the phase and intensity of the surface plasmon was simulated and then the phase shift of surface plasmon wave was experimentally measured by heterodyne polarization Interferometry. The response of sensing head to the refractive index change of surrounding medium were obtained. According to the obtained results, the average sensitivity of the phase in the solution of water/alcohol was 0. 4426 degree/%gr/ml and for the solution of water/glucose was 1. 4765 degree/%gr/ml. The detection limit for solution of water/alcohol and the solution of water/glucose were measured 0. 49 %gr/ml and 0. 14 %gr/ml, respectively.

Tectonic and constructional movements have always played an important role in geomorphological changes. Identifying the nature of recent constructional movements has been of importance in understanding and interpreting landforms. In this research constructional movements in Eshtehard and Qazvin, located in the south and southwest of Tehran and southern slope of Alborz Mount, are investigated using Radar Interferometry and geomorphological map of the basin. This technique is done using the images of Sentinel 1, which is located in band C radar range, with the average wave-length of 5/6 GHz. Geomorphological map of study area is provided in ArcMap GIS software, using Google-Earth images, DEM, Geological map, field visit, and sampling of landforms. Sentinel 1 Radar images are received from European Satellite site. Monitor changes are applied in SNAP software. According to the results of Radar Interferometry from 2015/10/3 to 2017/10/2, the whole study basin is tectonically rising. However, the rate of uplift in west and northwest of basin is greater than eastern and southern parts. Investigating geomorphological evidences such as consecutive alluvial fans, deviation of alluvial fans and remnants of lake terraces is totally in accordance with results from Radar Interferometry indicating a high tectonic deviation speed in northwest of basin, that is around the city of Qazvin and Takestan, comparing with south and south-western of the basin. Extended Abstract 1-Introduction Neo-tectonic movements have created new surface landforms and controls their shapes and positions. So in the areas locating in tectonic activities’ range, there are forms which have been created under the influence of these activities. By investigating the forms mentioned above, it is possible to understand tectonic movements in most regions. However, using geo-morphological evidence for investigating tectonic movements is not useful in all regions, especially in the regions where erosion and other factors may reduce tectonic effects on geomorphology. In such regions using geo-morphological evidence is either inapplicable or very difficult and the results come with great doubts. A way used in computing displacement of events on earth’ s surface, is Radar Interferometry including unique capabilities in terms of dimensions, cost, time and accuracy over other techniques. However, it should be noted that the use of this technique yields accurate results, especially in obtaining tectonic displacement rates, depending on the special features such as the base line, the polarization, the time interval between the two images, the time taken to take two images, passing sensors and so on. By following these tips, you can get great results from this technique. Therefore in this research we try to assess the rate of movements and its evidence in Qazvin and Eshtehard Plains in the past years. 2-Materials and Methods In this study, sentinel 1 images and geomorphology map are used to investigate tectonic dynamics. The date in which first image was taken is 2015/10/02, and the second day is 2017/10/03 with 731-day interval. The baseline rate is 47 meters than the original image that shows an acceptable rate in doing Radar Interferometry. For both images vv polarization has been used which is suitable for surface change measurement. In order to draw geomorphological map of the study area for recognizing geomorphological shapes, we used geological map of the region, Hill-shade, Satellite images, Google Earth images, Aerial Photos and Digital elevation Model (DEM). So, basic information about geomorphological landforms was obtained and an initial map of the geomorphology of the region was drawn. Then, in a field visit of the area, the landforms drawn on the map, were matched within the landforms on the earth and the items that were hard to detect on the map, were recognized. Finally, the supplementary map was detected. And in another field visit, the map bugs have been fixed. 3-Results and Discussion Consistency between images is more than 0. 2 and in a range between 0. 23 and 0. 25. The pixel density above 0. 6 is very small including 10% of all pixels. The phase difference values for pixels in Radar Interferometry, are between 3. 14 to-3. 14. Extensive patterns of fringes are related to tectonic movements in the region that are visible on plain margins and highlands. However, obtained maps of the phases are very complicated and in order to show them in real forms, they must be unwrapped. Opened phases indicate the general trend of phase changes in the region. But to investigate tectonic evidence reflected in landforms, the region’ s geological map has also been used. The major sequences of alluvial fans are seen in the north basin and around Qazvin and Takisatan. Between these two cities sequence of three young alluvial fans and one old alluvial fan are noticeable. 4-Conclusion Having a look at this study, we conclude that the rate of tectonic uplift in northern margins of Qazvin and Eshtehard Plain Basin is more than that of southern parts. However, in the whole northern margins of the basin, this uplift is not the same; in northwest and west is more than northeast and east. In other words Qazvin and Eshtehard Plains around the cities of Qazvin and Takestan have the most uplift resulting in 3 new consecutive alluvial fans and an old one. In the north of Eshtehard plain there are low stretched hills that are 5 meters higher than surrounding areas. These parallel hills are stretched from south to the north with a west to east direction consisting of clay without layers that include a very calm and low slope deposition not so long ago. The erosion and direction of these clay deposits shows tectonic uplift in the west and north of the study area.

Introduction: According to the US Geological Survey, the phenomenon of land subsidence involves the collapse or downward saturation of the earth that can have a slight displacement vector. Earth subsidence is a geological phenomenon that causes the earth to descend slowly and horizontally. This phenomenon is due to a variety of factors including natural factors such as earthquakes, volcanoes, fault activity, subsidence caused by sea level rise, dissolution in rocks, oxidation, compaction of organic sediments, pit development in karst lands, or human activities, Includes unseasonable harvesting of fluids from the ground such as oil and gas water. In recent years, in Iran, with the increase in the amount of subsidence due to buildings, runways, bridges, tunnels, streets, rail and road transport, agricultural facilities change the direction and direction of river movement. The canals and canals and fertility of agricultural lands have been damaged and also damages the flow pattern of hydrology, tilting and diversion of power towers and so on. Buildings that are larger and taller are more vulnerable, such as railways, earthen dams, canals, power towers and telecommunications. Research Methods: The method of this study is analytical and field research. In this study, ground data consisting of 18 piezometers from 1382 to 1396 for the calculation of groundwater loss rates, groundwater levels in the minimum and maximum periods were prepared by interpolation of their interpolation maps. Exploration wells were used to calculate aquifer discharge levels and radar data including Sentinel 1 images were used to calculate subsidence rates from 2015 to 2018 and finally between the groundwater and subsidence factors in the correlation area. It was obtained from field survey data of their validation Discussion: In this research, differential radar Interferometry has been used to determine the extent and extent of subsidence in Noorabad plain. In order to produce spatial pattern maps of the extent and amplitude of the meeting, a pair of radar sensors were used at different time intervals to perform Interferometry. Due to the variability of the amount and amplitude of the meeting, caused by water harvesting as a positive factor as well as the role of natural endowments (precipitation) as a moderating factor, images were processed over time periods consistent with the crop calendar and rainy seasons. . The findings confirm the occurrence of a maximum annual subsidence of 3 cm in an area of 186 square kilometers. The occurrence of such phenomena is largely contemplated due to agricultural structures in other parts of Iran, because in Iran, due to the existence of a special agricultural calendar for irrigation in spring and summer, as well as the possibility of recharge in winter and early spring, The relative importance of the table and its impact on meeting rates for later periods is accepted and relatively inclusive. With the output of radar imagery output over 4 years, the results show that from 2015 to 2018, the aquifer level will increase substantially, with areas in the central and eastern parts of the aquifer having the highest aquifer rate in the regions. The residential and agricultural area has been developed in such a way that the effects of these meetings are evident in the residential and agricultural land and the blue areas show signs of uplift when descending to a subsidence area. It does not occur, but rather a double or elevated aquifer surface. In the analysis section, we study the status of the subsidence rate in the study area using radar images during the years mentioned, by examining the status of the piezometers and the rate of subsidence during these years showed that the situation of the subsidence area which is very high in 2015 is 8 km Which is 34 km in comparison to 2014 and in 2016 is 40 and 86 in 2017 and 2018 respectively. Based on the maps we see in these 4 consecutive years that we see the sum of each year The level of the plain has been increased and thus the summit on the plain has become a danger. Conclusion: The average subsidence rate is about4 cm per year. The average subsidence over the four years is about 36 square kilometers of aquifer area, which covers about 5% of the area, with wells concentrated and the highest groundwater abstraction and concentration of existing cities and villages. In these areas, due to the water supply of the residential community including Nourabad and the surrounding areas, as well as the supply of water to the industrial sector, including factories and agricultural activities, the availability of more water resources and the availability of groundwater is very high. The high drop has been attributed to the high potential of these areas in the subsidence debate with the involvement of arid climates in the area, and has been identified as one of the critical areas of the city in the subsidence map. Radar Interferometry results show that excessive withdrawal from the surface of the underground reservoirs has caused the downstream portion of the aquifer to collapse, as well as the presence of numerous aquifers at the aquifer level causing damage to residential sites. One of the areas most exposed to flooding in the plain is the groundwater loss in the eastern, central and southern part of the aquifer within about 14 m of about 14 m in the same well and the results of R2 coefficient correlation of 72% The significance level of 99% was obtained indicating that there is a direct relationship between these two parameters.

Phenomenon of land subsidence in recent decades has created many problems for agricultural lands, residential areas, roads and water channels in some of the plains in Isfahan province. The southern Mahyar plain is located in 50 km of southeastern Isfahan. It is one of the areas where the excessive withdrawal of ground water resources (mainly in the agricultural sector, based on available information) has substantially grown in recent years. The amount of water extracted from underground has increased from 58.8 million cubic meters (from 217 wells) in 1369 to 85.5 million cubic meters (from 446 wells) in 1388. The decline in water table increases the effective stress that causes consequences such as land subsidence and cracks in some parts of the southern Mahyar plain. To determine the effectiveness and ultimately to estimate the rate of subsidence, radar Interferometry was used in this study. It is a reliable method to measure changes in the land surface, with very high accuracy, wide coverage and high spatial resolution. Maximum rate of subsidence was calculated at 8.2 cm/year using ENVISAT satellite radar images in the period of 2003-2006. The results of time series analysis showed that the land surface in the zone of danger is falling as a result of a decline in water table levels at a constant rate.

Subsidence is an environmental phenomenon caused by the gradual subsidence or sudden subsidence of the earthchr('39')s surface. The phenomenon of subsidence in residential, industrial and agricultural areas can cause catastrophic damage. In most parts of Iran, there is a high correlation between land subsidence and the decrease of groundwater level and consequently the density of soil layers. In this study, using two time series of radar images with artificial apertures from Sentinel sensors belonging to 2014 and 2019, the amount of subsidence in Damaneh plain (Frieden city) was calculated. Wells were studied in the period 2014 to 2019, the results of the study of the correlation between land subsidence with changes in groundwater level at the level of 95% was significant. In the continuation of the research, using the logistic regression model, the subsidence trend in the study area was predicted and a subsidence probability map was prepared and created as a dependent variable for the logistic regression model. The independent variables used included altitude, slope, slope direction, geology, distance from the road, distance from the river, land use, distance from the village, groundwater level, piezometric wells. The output of the model is subsidence risk zoning map which was created in five classes. The accuracy and validation of the logistic regression model was evaluated using the system performance characteristic curve and the accuracy (0.89) was obtained. The good accuracy of the logistic regression model in producing the probability map Subsidence is in the study area. In the output of the model, it was found that the area of ​​1980 hectares, equivalent to 7.9%, has a very severe subsidence that has put the situation in a dangerous situation and the need for control and management to reduce this destructive effect.