SOLID STATE FLIGHT DATA/VOICE RECORDER

SOLID STATE FLIGHT DATA/VOICE RECORDERS (SSFD/VR) USE EXPENSIVE SEMICONDUCTOR MEMORY DEVICES TO STORE SENSOR PARAMETER DATA AND VOICE DATA FOR ANY GIVEN FLIGHT. THE RECORDING TIMES FOR LARGE CIVILIAN AIRCRAFT CAN BE AS MUCH AS 25 HOURS FOR CONTINUOUS RECORDING OF SENSOR PARAMETER DATA AND 30 MINUTES FOR THE COCKPIT VOICE CHANNELS. THIS DATA REQUIRES VERY DENSE (AND CONSEQUENTLY EXPENSIVE) SEMICONDUCTOR MEMORY DEVICES TO CONTAIN THE RAW RECORDED DATA. ONE METHOD OF REDUCING THE REQUIREMENT FOR LARGE AMOUNTS OF SEMICONDUCTOR MEMORY IS TO COMPRESS THE DATA BY APPLYING DATA COMPRESSION TECHNIQUES CURRENTLY AVAILABLE. SPECTRUM SCIENCES, INC. PROPOSES TO EVALUATE DIFFERENT COMPRESSION TECHNIQUES FOR SENSOR PARAMETER DATA BY COLLECTING PERFORMANCE DATA DURING ACTUAL EXECUTION OF PROGRAMMED ALGORITHMS. VOICE COMMUNICATION REQUIRES A DIFFERENT APPROACH TO DATA COMPRESSION. LARGE AMOUNTS OF SEMICONDUCTOR MEMORY CAN BE USED UP QUICKLY IF COMPRESSION TECHNIQUES ARE NOT UTILIZED. A NEW FEDERAL STANDARD ALGORITHM FOR LINEAR PREDICTIVE CODING (LPC) HAS RECENTLY BEEN RELEASED. THE ALGORITHM REDUCES THE VOICE COMMUNICATIONS TO A LOW 4800 BITS PER SECOND DATA STREAM WHILE STILL MAINTAINING INTELLIGIBILITY. A SECOND PROPOSED TASK IS TO PERFORM A TOP LEVEL SYSTEM DESIGN TO DEVELOP THE METHODOLOGY FOR IMPLEMENTING THE NEW FEDERAL STANDARD.