Geometric correction

Geometric correction in remote sensing refers to the process of removing geometric distortions from images acquired by a sensor. These distortions can be caused by factors such as sensor tilt, altitude, and terrain curvature. The goal of geometric correction is to produce an image that is geometrically accurate, meaning that the features in the image correspond to their true locations on the ground.

One commonly used method for geometric correction is called rectification. This involves transforming the image so that it is projected onto a uniform scale, such as a map projection or a digital elevation model. This can be done using a process called orthorectification, which involves using information from the sensor's attitude and position, as well as a digital elevation model, to correct for distortions caused by terrain relief.

For example, an image of a mountainous area acquired by a sensor mounted on an aircraft may appear distorted due to the angle of the sensor and the shape of the terrain. After orthorectification, the same image would appear as if it had been acquired from directly above, with the terrain appearing flat and the features in the image corresponding to their true locations on the ground.

Comments

Geography of Landslides. Mitigation and Resilience.

A landslide is a geological event in which a mass of rock, earth, or debris moves down a slope under the force of gravity. Landslides can range in size from small to large and can be triggered by natural events such as heavy rainfall, earthquakes, or volcanic activity, or by human activities such as construction or mining. The geography of landslides is affected by a variety of factors that can increase the likelihood of landslides occurring in a particular area. These factors include slope angle and steepness, the type of soil and rock present, the climate and weather patterns of the region, the presence or absence of vegetation, and human activities such as construction, mining, and deforestation. Areas with steep slopes are more prone to landslides because gravity has a stronger effect on loose soil and rock, making it more likely to move downhill. Similarly, areas with loose, sandy soil or weak, fractured rock are more prone to landslides because they are less stable and more easil...

Geography of Flood. Types. Charector.

The geography of floods refers to the characteristics and patterns of floods in different geographic regions. Floods can occur in various landscapes, such as mountains, plains, coastal areas, and urban environments. The geography of a region plays a significant role in determining the frequency, magnitude, and impacts of floods. Some of the factors that influence the geography of floods include: Topography: The shape and elevation of the land can affect the flow and accumulation of water during a flood. For example, flat terrain can lead to slow-moving and widespread flooding, while steep slopes can result in flash floods and landslides. Climate: Regions with high rainfall or snowmelt can experience more frequent and intense floods, while dry regions may experience flash floods due to sudden, heavy rainfall. Hydrology: The characteristics of a river basin, such as its size, shape, and water flow, can influence the severity of a flood. For example, large river basins with extensive floo...

Landslides. USGS

Landslides. TYPES OF LANDSLIDES The term "landslide" describes a wide variety of processes that result in the downward and outward movement of slope-forming materials including rock, soil, artificial fill, or a combination of these. The materials may move by falling, toppling, sliding, spreading, or flowing. The animated GIF shows a graphic illustration of different types of landslides, with the commonly accepted terminology describing their features. The various types of landslides can be differentiated by the kinds of material involved and the mode of movement.

Flood prone regions India

Floods are natural disasters characterized by the overflow of water onto normally dry land. Various factors contribute to floods, including intense rainfall, rapid snowmelt, storm surges from coastal storms, and the failure of dams or levees. The geographical explanation involves understanding the key components of flood-prone regions: 1. Proximity to Water Bodies: Flood-prone regions are often situated near rivers, lakes, or coastal areas. These locations are more susceptible to flooding as they are in close proximity to large water sources that can overflow during heavy precipitation or storms. 2. Topography: Low-lying areas with gentle slopes are prone to flooding. Water naturally flows to lower elevations, and flat terrains allow water to accumulate easily. Valleys and floodplains are common flood-prone areas due to their topographical characteristics. 3. Rainfall Patterns: Regions with high and concentrated rainfall are more likely to experience flooding. Intense and prol...

Volcano

Large magma chamber Bedrock Conduit (pipe) Base Sill Dike Layers of ash emitted by the volcano Flank Layers of lava emitted by the volcano Throat Parasitic cone Lava flow Vent Crater Ash cloud

Vineesh V, Geography

Search This Blog