Investigation of air transportation technology at Ohio University, 1990-1991

The status of the Joint University Program is given. Brief synopsis of some areas of research follow. The study of spectrum efficient methods for transmitting weather information to aircraft has resulted in definition of an improved amplitude and phase modulation process which permits reutilization of voice channels for both voice and data. The system is being implemented for testing. Multisensor navigation systems introduce increased flexibility and performance for aviation, at the expense of increased complexity. Insuring a high level of system reliability and integrity requires that faults not only be detected, but also isolated to specific elements, so that the remaining capabilities of the system may be used with confidence. An algorithm was developed. The JUP has served as a vehicle for reporting work accomplished in evoked potential vision tracking experiments to determine the engineering parameters of this input and control method. Application of GPS in an interferometric mode permits accurate measurement of differential motion; aircraft attitude may be determined using GPS only, with multiple antennas

Loran-C approach considerations

The use of Loran-C during approaches to landing is investigated. The Avionics Engineering Center has evaluated such approach applications at Galion, Ohio Municipal Airport and at Mansfield, Ohio Lahm airport. Loran-C data were referenced to ground tracker data to determine that the Loran-C approach path was straight, flyable, and parallel to the runway centerline. The Loran-C operational issues that were investigated are listed

Processor-controlled timing module for Loran-C receiver

Hardware documentation is provided for the modified Loran-C timing module, which uses direct software control in determining loop sample times. Computer loading is reduced by eliminating polled operation of the timing loop

Modified timing module for Loran-C receiver

Hardware documentation is provided for the modified Loran-C timing module, which used interrupt-driven software control in determing loop sample times. Computer loading is reduced by eliminating polled operation of the timing loop

Microprocessor-to-system/370 interface

The design and operation of a microprocessor interface unit which allows use of a computer terminal for communication at 110 or 300 baud both with a central host computer and with the microprocessor monitor are documented. Additionally, the interface permits the host computer to load the microprocessor memory directly with object code, avoiding the use of intermediate data storage such as paper tape. The central computer, containing an assembler language processor for the target microcomputer, can be used from the terminal with all the flexibility offered by the virtual machine facility, producing object code for the micro plus program listings and supporting outputs. The object code can then be loaded directly to the micro and the same terminal device used to run the micro program, communicating with the micro's monitor routine

Loran-C flight data base

Loran-C time-difference data were collected on January 9, 1979 during a flight from Athens, Ohio to Madison VOR in Connecticut, thence to Millville VOR in New Jersey, and a landing at Atlantic City NAFEC. Portions of the return trip to Athens, Ohio were also recorded. Loran-C GRI data frames were recorded using the 99600 U. S. Northeast Loran chain stations Seneca/Nantucket (TDA) and Seneca/Carolina Beach (TDB). The GRI sequence number TDA and TDB were recorded as integer numbers, with the TD's in integer microseconds. Actual time-of-day can be determined from the data start time, plus the time per GRI and the sequence number. The low cost Loran-C receiver was used to obtain the time-difference data for each GRI. Data was recorded on digital magnetic tape and post-processed into latitude and longitude using an IBM system/370 computer

Demonstration program for Omega receiver prototype microcomputer data processing

The JOLT (TM) commercial microcomputer, based on the MOS Technology 6502 processor chip, for use in Omega navigation system is evaluated. A computer program was prepared in hand-assembled code to demonstrate receiver operation. The processor provides binary processing with interrupts enabled, a carriage return is given to initialize the teleprinter, and a jump is performed to enter the program loop to wait for an interrupt. The program loop operates continuously testing the interrupt flag. The interrupt routine reads the receiver status word and determines whether the current time-slot is the A slot. If so, the interrupt flag, which is also the data index pointer, is reset to zero. The status word is stored in the status buffer. If the time-slot is not A, the interrupt flag/pointer is incremented by one to index the phase and status to the proper buffer words for later use by the print routine

Test program for 4-K memory card, JOLT microprocessor

A memory test program is described for use with the JOLT microcomputer 4,096-word memory board used in development of an Omega navigation receiver. The program allows a quick test of the memory board by cycling the memory through all possible bit combinations in all words

A memory-mapped output interface: Omega navigation output data from the JOLT (TM) microcomputer

A hardware interface which allows both digital and analog data output from the JOLT microcomputer is described in the context of a software-based Omega Navigation receiver. The interface hardware described is designed for output of six (or eight with simple extensions) bits of binary output in response to a memory store command from the microcomputer. The interface was produced in breadboard form and is operational as an evaluation aid for the software Omega receiver

A microprocessor interface for the Ohio university prototype Omega navigation receiver

The Ohio University Omega Prototype Receiver is currently under final design and construction. As initially designed, digital and analog hardware outputs were provided for attachment of tape recorders or chart recording equipment for capture of Omega LOP data. The interface described was designed to demonstrate the concept of direct microprocessor attachment to the existing receiver to allow far more flexibility of output data handling than previously provided