PULSTRAC: POSITIONING WITH SPREAD-SPECTRUM TECHNIQUES.

Spread-spectrum radiolocation techniques offer the surveyor or hydrographer real-time extraction and correction of system biases to eliminate fixed timing errors. Pulstrac - developed by Del Norte Technology (Euless, Texas) - uses a proprietary technique with the traditional number of shore reference stations allowing an unlimited number of passive users to obtain additional lines of position as well as calibration information. The increased lines of position and continuous calibration monitoring provide a positional confidence factor to the hydrographer in real time. A single frequency can be used worldwide since 'networks' are identified by code. Adjacent networks can be indicated to the user through the system description data, thus facilitating network-to-network operation without operator intervention. Although Pulstrac's accuracy is excellent for hydrographic survey, the automation of dynamic precise positioning is most advantageous in pilotage and navigation.