What is Orthoimagery?
Orthoimagery is an accurate representation of the Earth’s surface (source). When images are taken from aerial or satellite positions, distortion occurs (source). This means that the image taken is not an accurate representation of the space. This can be corrected through a process called orthorectification. After correction, distances can be accurate to the nearest four centimetres (source).
What are some common uses of Orthoimagery?
Orthoimagery is used in geographic information systems (GIS). GIS is a way for people to analyze the world. It makes use of data such as pollution density or building locations, to create maps for the user. The user can gain valuable insights by using different combinations of data layers.
Orthoimagery is used in GIS because of its ability to provide accurate spatial data. The user can make observations and conclusions, such as monitoring the changes occurring in a certain area (source). For example, Niwot Ridge Long Term Ecological Research program is monitoring changes to better understand ecosystems in mountainous regions (source). In the photo, layers of data collected from past decades are shown to visually represent the changes in the landscape. Some other examples that use orthoimagery include: road safety analysis, urban growth, disaster management, and location identification (source).
What are some advantages of Orthoimagery?
Orthoimagery is accurate and helps users conduct precise analyses. It can also provide the user with a high degree of detail, depending on the level of resolution. The higher the resolution, the higher the detail (source).
What are some challenges of Orthoimagery?
One of the challenges of orthoimagery is coordinating the collection of data. Many different groups value and use the data collected (e.g. federal government, municipalities, industries). As a result, sometimes the same areas are captured multiple times. This overlap of acquiring data is an inefficient use of resources in society. There are also different standards and objectives within each group around quality and technique. For example, an individual looking up the distance from their house to the grocery store, and a company assessing land allotments would require different levels of quality and accuracy. There is also an ongoing issue within private and public sectors around which parties should have access to certain GIS data sets (source).