Phase coherent Kinematic applications, such as attitude determination, survey, and phased array multiple antenna systems, place extreme requirements on the Constellation Simulator hardware and controlling software.  For multiple RF outputs with common satellites on each RF,  precise control of the initial value for carrier phase as well as the relative value is required. The X14-DSPM and Tapestry controlling software have collectively solved this problem by implementation of our combined digital signal with a common RF up-conversion stage the avoids the uncertainty of the initial carrier phase value. We have tested this system in a 4-RF configuration with a Trimble ADS system and the results were excellent. Our Tapestry software provides the following features which support multiple RF output carrier phase applications.   

·        The Tapestry system allows for the creation of two vehicles simultaneously within one scenario. The two vehicle motion profiles can be completely independent with each vehicle modeled to its own separate RF output. In this system one vehicle can be dynamic and the other stationary (base station) or both vehicles can be dynamic. Our software automatically manages the GPS uploads and satellite selection independently for both modeled vehicles. 

·        We have constructed an 8 RF output system in which we have mapped each satellite to a separate RF output. This system has been used as input to a wave-front delay matrix for injection into a Controlled Reception Pattern (CRPA) antenna system. We are in the process of incorporating all of the phase-delay matrix elements within our system. 

·        4-antenna lever arms. These are defined in the vehicle BODY frame with both position offsets from the vehicle center-of-mass as well as the capability to define the cone-angle, and orientation of the main antenna beam lobe.  The antenna motion experienced under dynamics is fully modeled by the Tapestry software continuous through angular jerk. Our system includes a terrestrial and spaceborn 6-DOF motion generator that includes full attitude maneuvering.  Included is mutli-element satellite selection algorithm. The user can either force common satellites on each antenna element or configure each antenna independently. This was extremely useful for a spaceborn application in which the spacecraft was rotating a 1 rev/min with 4 antenna elements spaced 90^o apart in look angle. In this case we selected new satellites every 5 seconds independently on each antenna element as there was minimal common sky coverage.  4-element vehicle silhouette masks are provided. The user may develop independent vehicle silhouette effects for each antenna. These masks are 1^o x 1^o  (default is 5 ^o x 5 ^o) with both upper and lower hemisphere patterns.

Navigation Laboratories Inc. (949) 766-0444, (949) 495-9551, Fax (949) 713-2479