Applied Geography

Edge detection is a common technique used in remote sensing to identify and extract the boundaries or edges of objects in an image. This can be useful for identifying changes in land cover, detecting features such as roads or buildings, and improving the overall interpretation and classification of an image. Edge detection algorithms typically use mathematical techniques to identify abrupt changes in pixel values within an image. These changes may indicate the presence of an edge or boundary between two distinct objects or areas. Edge detection is an important tool in remote sensing for a number of reasons. It can be used to identify objects or features in an image, such as roads, buildings, or vegetation. It can also be used to improve image classification by highlighting important features that may not be easily visible in the raw data. Additionally, edge detection can be used to improve image registration and mosaicking, by providing a common reference point for aligning multiple im...

Spatial filtering encompasses another set of digital processing functions which are used to enhance the appearance of an image. Spatial filters are designed to highlight or suppress specific features in an image based on their spatial frequency. Spatial frequency is related to the concept of image texture. It refers to the frequency of the variations in tone that appear in an image. "Rough" textured areas of an image, where the changes in tone are abrupt over a small area, have high spatial frequencies, while "smooth" areas with little variation in tone over several pixels, have low spatial frequencies. A common filtering procedure involves moving a 'window' of a few pixels in dimension (e.g. 3x3, 5x5, etc.) over each pixel in the image, applying a mathematical calculation using the pixel values under that window, and replacing the central pixel with the new value. The window is moved along in both the row and column dimensions one pixel at a time and the ca...

Spatial feature manipulation in remote sensing refers to the process of altering or modifying the spatial characteristics of a particular feature in an image or data set. This can be done for a variety of reasons, such as to improve the accuracy or clarity of the image, to enhance the interpretability of the data, or to extract specific information from the image. One common method of spatial feature manipulation is resampling, which involves changing the resolution or spatial extent of an image. This can be done to match the resolution of other data sets, to reduce the size of the image for faster processing, or to increase the resolution for greater detail. Another technique is spatial filtering, which involves applying mathematical operations to the image data to remove noise or highlight specific features. This can be done using convolution filters, which apply a pre-defined mathematical function to the image data, or using image enhancement techniques, such as contrast stretching ...

Filtering in Remote Sensing. Convolution. Edge enhancement. Low pass filter and High-pass filter Spatial filtering is a technique used in remote sensing to enhance the spatial resolution of an image. This is typically done by using a mathematical algorithm to process the raw data collected by the remote sensing instrument, with the goal of reducing noise and improving the overall quality of the image. Spatial frequency in remote sensing refers to the density of spatial details or features in an image. It is a measure of how quickly the intensity or brightness of an image changes over a given distance. High spatial frequency indicates a high density of fine details or edges in an image, while low spatial frequency indicates a low density of fine details or edges. Spatial frequency is an important concept in remote sensing because it can affect the ability to detect and interpret features in an image. It can also be used to evaluate the quality and usefulness of an image for certain type...

Spatial filtering encompasses another set of digital processing functions which are used to enhance the appearance of an image. Spatial filters are designed to highlight or suppress specific features in an image based on their spatial frequency. Spatial frequency is related to the concept of image texture. It refers to the frequency of the variations in tone that appear in an image. "Rough" textured areas of an image, where the changes in tone are abrupt over a small area, have high spatial frequencies, while "smooth" areas with little variation in tone over several pixels, have low spatial frequencies. A common filtering procedure involves moving a 'window' of a few pixels in dimension (e.g. 3x3, 5x5, etc.) over each pixel in the image, applying a mathematical calculation using the pixel values under that window, and replacing the central pixel with the new value. The window is moved along in both the row and column dimensions one pixel at a time and the ca...

Grey level thresholding. Level slicing. Contrast stretching. Image enhancement Lillesand and Kiefer (1994) explained the goal of image enhancement procedures is to improve the visual interpretability of any image by increasing the apparent distinction between the features in the scene. This objective is to create "new" image from the original image in order to increase the amount of information that can be visually interpreted from the data. Enhancement operations are normally applied to image data after the appropriate restoration procedures have been performed. Noise removal, in particular, is an important precursor to most enhancements. In this study, typical image enhancement techniques are as follows: Grey level thresholding Grey level thresholding is a simple lookup table, which partitions the gray levels in an image into one or two categories - those below a user-selected threshold and those above. Thresholding is one of many methods for creating a binary mask for an i...

What is an Aquifer? An aquifer is a body of saturated rock through which water can easily move. Aquifers must be both permeable and porous and include such rock types as sandstone, conglomerate, fractured limestone and unconsolidated sand and gravel. Fractured volcanic rocks such as columnar basalts also make good aquifers. The rubble zones between volcanic flows are generally both porous and permeable and make excellent aquifers. In order for a well to be productive, it must be drilled into an aquifer. Rocks such as granite and schist are generally poor aquifers because they have a very low porosity. However, if these rocks are highly fractured, they make good aquifers. A well is a hole drilled into the ground to penetrate an aquifer. Normally such water must be pumped to the surface. If water is pumped from a well faster than it is replenished, the water table is lowered and the well may go dry. When water is pumped from a well, the water table is generally lowered into a cone of dep...

<iframe style='width:900px;height:500px' src=' https://online.pubhtml5.com/fjpl/pxsm/ '  seamless='seamless' scrolling='no' frameborder='0' allowtransparency='true' allowfullscreen='true' ></iframe> https://online.pubhtml5.com/fjpl/pxsm/ Satellite Remote Sensing; Multispectral imaging; Using Discrete Detectors and Scanning mirrors- Landsat- MMS, TM, ETM+; NOAA- GOES, NOAA-AVHRR; SeaWiFS Multispectral imaging Using Linear Arrays; SPOT 1, 2, 3 HRV, SPOT 4, 5 HRVIR; IRS- LISS III and LISS IV; ASTER; Quick Bird Imaging Spectrometry using Linear and Area Arrays; AVIRIS, MODIS  Vineesh V AISHE and UGC Nodal Officer Assistant Professor of Geography, Government College Chittur, Palakkad https://vineesh-geography.business.site

International oceanographic program Intergovernmental Oceanographic Commission ,  UNESCO International Council for the Exploration of the Sea International Hydrographic Organization International Ocean Discovery Program , formerly called the  Integrated Ocean Drilling Program . InterRidge , an international research collaboration on oceanic seafloor spreading zones. North Pacific Marine Science Organization  (PICES) Scientific Committee on Oceanic Research , part of the  International Science Council . By American Geophysical Union Association for the Sciences of Limnology and Oceanography Coastal and Estuarine Research Federation European Geosciences Union The Oceanography Society India  Center for Marine Living Resources in Kerala, under the  Ministry of Earth Sciences .  CMLRE Central Marine Fisheries Research Institute, Kochi, Kerala, under the  Indian Council of Agricultural Research .  CMFRI National Centre for Ocean Information Services  in Pragathi Nagar, Hyderabad.  ESSO-INCOI...

Map scale refers to the factor by which the real world is reduced to fit on a map. A GIS is multiscalar. Map projections are mathematical formulas used to transform the three-dimensional earth to two dimensions (e.g., paper maps, computer monitors). Map projections introduce distortions in distance, direction, and area. Map Scale The world is a big place…really big. One of the challenges behind mapping the world and its resident features, patterns, and processes is reducing it to a manageable size. What exactly is meant by "manageable" is open to discussion and largely depends on the purpose and needs of the map at hand. Nonetheless, all maps reduce or shrink the world and its geographic features of interest by some factor. Map scale refers to the factor of reduction of the world so it fits on a map. Map scale can be represented by text, a graphic, or some combination of the two. For example, it is common to see "one inch represents one kilometer" or something simil...

Geodesy, Map Projections and Coordinate Systems. Warm Regards Geodesy- the shape of the earth and definition of earth datum, gravity field, earth rotation. • Map Projection- Transformation of the curved earth to a flat map.(3D->2D). • Coordinate systems-(x,y,z) coordinate systems for map data.