GPS & DGPS
EMI is leading provider of precision measuring instruments. The company is promoted by pioneers in the field of Surveying instruments, Laser instruments, GIS GPS equipments and other high precision systems. EMI diverse product line provides complete measurement solutions for surveying, mapping and GIS, industrial measurement and construction applications. Our products have been used to complete major projects. Our products are very reliable, accurate and work years together. We have a team of factory trained engineers to provide efficient and prompt after-sales-service to our customers.
The Global Positioning System (GPS), also known as Navstar, is a global navigation satellite system (GNSS) that provides location and time information in all weather conditions, anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites. The GPS system operates independently of any telephonic or internet reception, though these technologies can enhance the usefulness of the GPS positioning information. The GPS system provides critical positioning capabilities to military, civil, and commercial users around the world. The United States government created the system, maintains it, and makes it freely accessible to anyone with a GPS receiver.
Differential Global Positioning System (DGPS) is an enhancement to Global Positioning System that provides improved location accuracy, from the 15-meter nominal GPS accuracy to about 10 cm in case of the best implementations.
DGPS uses a network of fixed, ground-based reference stations to broadcast the difference between the positions indicated by the GPS satellite systems and the known fixed positions. These stations broadcast the difference between the measured satellite pseudoranges and actual (internally computed) pseudoranges, and receiver stations may correct their pseudoranges by the same amount. The digital correction signal is typically broadcast locally over ground-based transmitters of shorter range.