A digital threat generation node for a SIMNET/DIS tactical aircraft network

Abstract

The Flight Simulation Laboratory (FSL) at General Dynamics, Fort Worth Division, is continuing to develop a SIMNETIDistributed Interactive Simulation local area network. This network was developed to support engineering studies and aircrew training simulation. The latest upgrade to this network includes a digital threat generation node to provide a unique combination of evaluation and tactics training scenarios. Although the SIMNETIDIS protocol provides an inexpensive approach to networking many simulators together, there is a need for an automated force structure in addition to the manin-the-loop network nodes. This capability will allow increased flexibility in the blue vs red test and training scenario combinations, while reducing required test support resources. The threat generation model used for this study was re-hosted from a Harris H-1000 computational platform to a Motorola 88100 VME computer system. This threat model has been tested and used extensively in the FSL for engineering studies and F-16 aircrew tactics training. This paper will discuss the initial configuration developed at General Dynamics, which used a dual simulator F16 configuration to test the SIMNET protocols for tactical aircraft. The results from this baseline developed the rationale for additional investigation into the use of a threat node on the network to generate Airborne Interceptor (Al) aircraft and Surface-to-Air missile sites. The three steps used to integrate this threat node on a network will also be discussed. These steps are: 1) the threat model re-host task between the two computer platforms, their differences and performances, 2) the integration techniques used in installing the digital threat generation node on the General Dynamics local area simulation network, and 3) the addition of any protocol extensions or computational platform modifications necessary to complete the integration. General Dynamics' interest in the SIMNETIDIS approach to network simulation began with discussions with the Armstrong Laboratory (ALHRA) personnel at Williams AFB. These discussions concerned the need to test many of these protocols for tactical aircraft. Dr. H. Bell and Maj. Kamrowski offered to loan General Dynamics network interface equipment to investigate the SIMNET protocols in the FSL. There was some initial skepticism by the FSL of the viability of using an ethernet network to provide real-time updates to high fidelity flight simulations. These concerns centered around the following: update rate, bandwidth saturation, position errors induced from the extrapolation routines, and visual fidelity of the networked aircraft. However, there were many advantages to researching these concepts and collecting hard data specifically for tactical aircraft simulation. Copyright O 1992 by General Dynamics Corporation. All rights reserved. Published by the American Institute of Aeronautics and Astronautics, Inc. with permission. This was also seen as an opportunity to find a low cost solution to network F-16 based training system products. Similar communication strategies could potentially be used as a standard means to communicate between the various engineering simulators in the FSL. If validated, these methods could further be extended to include the other Fort Worth facility laboratories. The investigation was broken down into three concerns for using the SlMNETlDlS methods. First, could the SlMNET Network Interface Units (NIU) connected through ethernet provide updates to the host computer systems at a sufficient rate? Second, would the visual scene presentation of the networked aircraft be of high enough fidelity for gun sight evaluations? Last, could actual end-game calculations be performed to determine the outcome of an aircraft engagement? J v 1 SlMUl ATlON CONFIGURATION Figure 1 shows the 1991 baseline configuration that was developed in the FSL. It includes two F-16 high fidelity flight simulators using Harris H-series host computer systems, Silicon Graphics 4D-series graphics generators for cockpit displays, and an Evans and Sutherland CT-6 visual scene generation system. The simulation host computer systems were connected using ethernet to the Network Interface Units (NIU) Motorola 147 processor. This connection was updated at the host computer's maximum frame rate of 50hz. The NlUs used the VME backplane as the means of communicating the SlMNET protocols. The ethernet packet communications protocol was maintained on the VME backplane to allow the configuration to use a Local Area Network (LAN) between the NlUs in the future. 24' DOME 1 24' DOME 2