| Today, aerial maps are used in dozens of | | | | be turned into a topographical map. This date can |
| different online mapping and driving direction | | | | be used in a wide variety of applications, from the |
| services, including MapQuest, Google Earth, Google | | | | creation of topographical maps to "fly through" |
| Maps, and specialized applications to show the | | | | simulations. This three-dimensional mapping |
| location of various features. Nearly every online | | | | system is very popular for engineers, planners, |
| use for online mapping is based on aerial | | | | mapping technicians, GIS professionals, and |
| photographs or maps. Geographic Information | | | | surveyors. Compared to similar methods for |
| Systems, or GIS, is a technology using | | | | three-dimensional information gathering, it is very |
| sophisticated maps created with aerial imagery via | | | | accurate, relatively fast, and cost-effective. |
| satellites to provide information about the terrain | | | | While LiDAR and related methods represent the |
| and specific land features. This imagery is available | | | | cutting edge of aerial surveying, the idea of aerial |
| in many different scales, in both color and black | | | | mapping and surveying dates back to the middle |
| and white formats, to highlight a range of | | | | of the nineteenth century, when hot air balloons |
| features depending on the specific application. | | | | allowed surveyors to take the first aerial |
| Today there are thousands of geospatial and GIS | | | | photographs. Aerial surveying grew in popularity |
| aerial maps in use. | | | | after the turn of the century. The 1957 launch of |
| Aerial mapping is also very important to land | | | | Sputnik marked the beginning of the satellite |
| surveying. While most parts of the earth have | | | | imaging era.One of the earliest forms of remote |
| been photographed at altitude to create a map, | | | | sensing used for the creation of maps was |
| most land surveying applications require a more | | | | photogrammery, a technique still used to the |
| detailed image of the land at a larger scale, along | | | | present day. This is the ability to determine |
| with the collection of more precise data points. | | | | measurements by using photography. Aerial |
| While aerial maps for general applications are most | | | | photogrammery, achieved with a camera in an |
| often created through the use of satellite | | | | airplane, involves the taking of photographs of the |
| imagery, land surveying applications are most | | | | ground every few seconds as the plane flies in a |
| often undertaken with the use of an airplane or | | | | straight line. This technique was first used with |
| helicopter. | | | | film cameras, although today digital cameras are |
| The main benefit of aerial methods of mapping | | | | used. By matching adjacent images, a complete |
| and surveying is that they are unobtrusive, and | | | | picture of the area can be created. Aerial |
| do not require setting foot on the actual terrain. | | | | photogrammery is used for terrain mapping, while |
| This is advantageous in situations with limited | | | | close-range photogrammery can be used for a |
| access to the land or dangerous terrain, such as | | | | survey of building facades or other features. By |
| areas with steep slopes. It is also important to | | | | taking photos from two slightly different angles, a |
| note that aerial surveys involve the creation of | | | | three-dimensional model (or Digital Elevation Model) |
| three-dimensional maps through precise | | | | can be created from the data collected. |
| measurements of elevation and location, in | | | | Aerial surveying and mapping methods are often |
| contrast to aerial photography, which generally | | | | preferred because they allow for the collection of |
| does not contain the same level of detail or data, | | | | data from a wide area in a short period of time, |
| although three dimensional models can be created | | | | particularly when compared to traditional surveying |
| using aerial photos. | | | | methods. The digital data collected using these |
| The most common aerial surveying method is | | | | methods is useful for surveyors, engineers, |
| LiDAR, which uses laser beams to create a | | | | geologists, city planners, and many other |
| three-dimensional map or image of the land. When | | | | professionals who require highly precise visual |
| combined with GPS equipment, LiDAR collects | | | | maps of an area. |
| information about elevation and location that can | | | | |