The principal use by which digital mapping has grown in the past decade has been its connection to Global Positioning System (GPS) technology. GPS is the foundation behind digital mapping navigation systems.
How it works
The coordinates and position as well as atomic time obtained by a terrestrial GPS receiver from GPS satellites orbiting Earth interact together to provide the digital mapping programming with points of origin in addition to the destination points needed to calculate distance. This information is then analyzed and compiled to create a map that provides the easiest and most efficient way to reach a destination.
More technically speaking, the device operates in the following manner
GPS receivers collect data from at least four GPS satellites orbiting the Earth, calculating position in three dimensions.
The GPS receiver then utilizes position to provide GPS coordinates, or exact points of latitudinal and longitudinal direction from GPS satellites.
The points, or coordinates, output an accurate range between approximately “10-20 meters” of the actual location.
The beginning point, entered via GPS coordinates, and the ending point, (address or coordinates) input by the user, are then entered into the digital mapping software.
The mapping software outputs a real-time visual representation of the route. The map then moves along the path of the driver.
If the driver drifts from the designated route, the navigation system will use the current coordinates to recalculate a route to the destination location.
In recent years, with digital maps and geographic information systems technology development and application of electronic maps came into being. With further development, many geographic information system applications will also be in the form of electronic map. Currently, the existing electronic map systems have achieved some results on research and application, but there are some issues leads to system can not play to their highest performance. How to design and develop scientific and efficient electronic map information system is a necessary requirement. In this paper, the design of data organization and functions are analyzed and studied to solve some practical problems. In some areas there will be of great practical significance.
The mapping lab is responsible for digitizing the geology, adding the necessary map components, performing layout tasks, and finally seeing the map through to publication. The lab collects and maintains metadata for each geology data set. The lab also maintains all generated geologic map data.
Geology is either digitized by hand on a high-accuracy digitizing tablet or scanned by high-resolution scanner with subsequent data conversion and extraction. IGS digitizes by tablet most new maps because this process can be accomplished entirely in-house. CADmappr semi-automates the digitizing process through a series of dialog box-driven routines. Digitizing proceeds unit-by-unit.
Only one copy of each contacts or fault-contact is digitized. Remaining dangling faults are then added. After that, geologic attitudes (strike and dip, foliation, etc..) and the other geologic symbols are digitized. Finally map unit labels are added including label points (points necessary for topology in a GIS.) Once digitizing is complete, a unit-by-unit visual on-screen check is done.
The map is plotted on Mylar for further line work inspection. Lines should look drawn, not digitized. Necessary additions and changes are then made. The digitizing of this database version of the map, takes place in Idaho State Plane Coordinates. Key metadata information is noted for each work