Flight Tracking and Messaging Systems

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Flight Tracking and Messaging Systems

Communications Group

Final Project Report

Joshua McCamey

Samuel Hurne

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Abstract

The FTMS team is working with an organization named JAARS to upgrade their in-flight

Automatic Flight Following System (AFFS). The original AFFS system requires a hardware

upgrade to allow for continued manufacturability. FTMS team members Joshua McCamey and

Samuel Hurne are addressing this issue by integrating an upgraded microprocessor with the

AFFS interface. The team has made progress towards developing a testing environment and

system firmware for the upgraded unit. The work done on this project will ensure the

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Introduction

For mission aviation organizations, there is a general need for adequate flight tracking

systems. In the 1990s, JAARS developed the Automatic Flight Following System (AFFS) in order

to meet the need of a standard flight tracking system for mission aviation organizations. MSI

and UIM also showed some interest a more flexible version of the system, since each

organization uses distinct communication methods. However, the microprocessor of the

original AFFS system is now obsolete and can no longer be manufactured. As a result, the Flight

Tracking and Messaging Systems (FTMS) project team has identified two main objectives for the

system: 1) Upgrade the original AFFS system to allow for manufacturing of new systems, and 2)

Increase the modularity in the system for use with other communication methods. To date, the

upgrade of the original AFFS system is underway and progress has been made in developing the

system with other communication systems.

Background

Mission aviation organizations serve to facilitate missionary transport, humanitarian

relief and community development for remote rural locations throughout the world. For those

organizations, there is a general need for flight tracking systems, since the remote locations

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to for a flight monitor to follow changes in flight itinerary while en route, and a safety

contingency in the event that a plane fails to arrive at its destination due to accident or other

unforeseen circumstance. Also, desirable is a means to pass simple text messages involving

critical flight information between the pilot and the flight monitor on the ground. For tracking

the system can utilize the Global Positioning System (GPS) technology, but the way to transmit

that location and other critical flight information varies with the particular mode of

communications used by an organization.

In the 1990s, JAARS, one mission aviation organization, developed a low-cost flight

tracking system entitled the Automatic Flight Follow System (AFFS). The system uses a

High-Frequency radio communications method with a wireless modem in order to communicate with

ground stations. Ground stations are outfitted with a program developed for the system

entitled AFFSWin. The program allows for tracking of flight coordinates by overlaying flight

paths over maps. It also provides an interface for ground stations to communicate with pilots

via text messaging. JAARS received a large amount of feedback from pilots, and the system was

designed to house a control unit within the airplane cockpit (one of the most highly regulated

environments in the world).

Other mission aviation organizations took notice of the system, including Mission

Aviation Fellowship (MAF) and UIM Aviation. These organizations desired to use the AFFS

system with different communication systems. JAARS would continue to use the Pactor radio

modem interface, MAF desired to work with a Codan radio, and UIM desired to interface the

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Unfortunately, due to passage of time and changes in the electronics market, the

central microprocessor within the AFFS system became obsolete. This prevented additional

units from being manufactured. Thus, the system requires an upgrade so that new units are

available for the JAARS aircraft fleet, and adaptable to the needs of other organizations. As a

result of the need, JAARS has allowed Messiah College to work with the AFFS hardware and

software under a Non-Disclosure Agreement (NDA) to develop an upgraded AFFS system that is

ready for continued manufacturing. In addition to the upgrade of the obsolete components of

the system, JAARS has expressed its openness to developing interfaces with other

communication methods, including the Codan radio interface for MAF and the satellite modem

interface for UIM.

The FTMS team of 2009 and 2010 took on the task of both upgrading the obsolete

components of the original AFFS system and investigating an interface with a Stellar ST2500

satellite modem provided by UIM. The team made good progress and developed a prototype of

the upgraded AFFS system, including a new microprocessor and progress on the actual port of

the original system code. In addition to the prototype, the team also began testing of a loaned

satellite modem and determined that the modem functioned properly and may be a viable

communication method.

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The FTMS team of 2010/2011 began project work essentially where the previous team

left off. In the fall of 2010, the team focused primarily on developing and investigating the

interface with the ST2500 satellite modem provided by UIM. Some testing had been completed,

but a more thorough analysis was necessary before development could continue with the

modem.

The Stellar ST2500 modem is an ORBCOMM low earth orbiting satellite transceiver. The

satellite modem sends messages via satellite through the ORBCOMM system, through the

internet, and finally to a specified e-mail address. Preliminary tests showed that the messaging

capabilities worked as described, and the team was able to send messages to specified e-mail

address. However, the modem required connection with a PC running the Microsoft Windows

operating system, as the modem utilized StelComm, a windows application. Additionally, tests

showed inconsistent satellite reception and signal strength, which was a concern considering

the purpose of flight tracking.

Despite these concerns, the team continued to research in order to learn how to

interface the modem with the new upgraded microprocessor. Documentation regarding the

modem was found, although descriptions and instructions on third party programming were

inadequate and confusing. In an attempt to understand the instructions better, the team

contacted Stellar directly. From Stellar, the team learned that the ST2500 satellite modem itself

was no longer support and had become obsolete. This posed a challenge to the team, as there

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In a final attempt to determine the programming capabilities of the satellite modem,

the team communicated with John Paepcke, a consultant for UIM from Time Critical Decisions.

John investigated the ability of third party programming for the modem, but also failed in

finding any sort of documentation or support. Because of the difficulties with the ST2500, the

team was forced to adjust the goals of the FTMS project until either more support is provided

or a more recent modem product could be provided.

Beginning in the spring of 2011, the FTMS team redefined the main objective of the

project. Instead of attempting to upgrade the AFFS system and interface the system with a

satellite communications system, the team decided to focus entirely on only upgrading the

AFFS system for manufacturability. In order to finish developing the system, the team identified

three sub-objectives: 1) Investigate original hardware composition and functionality in order to

ensure emulation of the original system, 2) Continue development on the firmware port for the

new system, and 3) Begin developing a testing environment for future testing of the new

system.

Investigation of the physical composition of the original AFFS system control unit led to

the discovery of an intermediate display and interface board. Further investigation showed that

the display board serves as an interface for the microprocessor, the Pactor modem, and all

other components. While the new microprocessor is physically smaller than the old

microprocessor, this was of concern because the new microprocessor contains a different

pin-layout than the original. As a result, the team determined that an interface board between the

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the functionality of the AFFS control unit showed that previous work done on the firmware did

indeed emulate the system.

Following investigation of the original AFFS system control unit, the team then moved to

developing the firmware of the new system. In accordance with stakeholder desires, the team

continued to ensure that strict emulation was followed while coding the new system

microprocessor. Work was necessary on the actual user-interface sections of the code, so the

team finished that first. Following the user-interface code, the team then moved to porting the

Pactor modem interface, beginning with the modem initialization. Finally, after completing the

modem initialization, the team then focused on beginning the port of the main modem and GPS

functionality. Significant progress was made, especially in the development of the emergency

button latch code. However, a large part of the code remains to be ported, and will likely be a

focus for future work on the project.

For the testing environment, the team began by adding a power switch to the prototype

in order to help emulate the original pilot interface. In addition, the team worked with JAARS to

obtain a second SCS PTC-IIpro Pactor modem for testing purposes. After speaking with Martin

Beels, a previous Messiah Graduate student that had worked with the AFFS system, the team

learned that a potential modem-to-modem interface would involve an audio patch cable,

entirely removing the initial need for a radio interface. Future testing would indeed require the

radio interface to be part of the system, but initial testing with an audio patch cable would

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Project Plan

In the fall of 2010, the Flight Tracking and Messaging Systems team had planned to

integrate a satellite modem with the AFFS 1.0 control unit in order to create SatAFFS. The

original plan involved having this system in the testing phase by December of 2010. However,

during the research phase it was discovered that the satellite modem we were attempting to

integrate with the AFFS control unit was not going to be a viable option for a SatAFFS system.

Programming of the satellite modem proved to be impractical based on the testing the team

did. Further research showed that the modem was no longer supported by the manufacturer

and that our contacts who had experience with the modem had never known of an instance

where it was programmed for specialized use.

In the spring of 2011 revised the schedule and plan to begin work on AFFS 2.0 instead of

SatAFFS (i.e. integrating the new microcontroller into the original system with the pactor

modem rather than with the satellite modem). Currently the project is in the research phase as

the code is being ported from the original microcontroller to the new one and the testing setup

is being configured. Work left to be done on the code porting side includes a small amount of

porting of the modem code as well as the entirety of the GPS code. On the test setup side the

ground station test modem must be successfully connected to a PC and a patch cable must be

connected between the ground and cockpit units. When that work is completed the project

should be prepared to enter the testing and design phases. The testing phase will involve first

testing AFFS 1.0 to analyze its functionality and then connecting the new micro to check that it

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adapter to connect the new microcontroller to the AFFS display board or designing another

creative and effective way of connecting the two.

The current schedule expected the testing phase to start in April 2011 and the design

phase to start in September 2011. However, the testing phase has now been pushed back to

the Fall of 2011 because the code porting and test setup ended up slightly behind schedule.

The code porting ended up slightly behind schedule due to the sheer quantity of code needing

ported. The job is simply taking longer than we initially anticipated. The test setup is still

incomplete because we have, as of yet, been unable to get the ground station modem

connected to a PC. This may either be a serial port assignment issue or the modem may not

work through a serial-USB converter. Once these two tasks are resolved the next stages of the

project can begin.

Currently all resource needs for the project are met. We do not anticipate a need for

any additional resources in the near future based on current project resources and status. The

project resources currently consist of the original AFFS control unit, a stand-alone pactor

modem, our updated replacement microcontroller, a breadboard-based prototype, and various

cables and serial-to-USB converters.

Because all of our resources needs are met now and for the foreseeable future, we have

no current financial challenges or expected expenses. The project is well within budget and is

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Future Work

Project work in the immediate future will involve the testing and design phases as

mentioned in the “Project Plan” section of this report. Once the testing and adapter design

phases are complete, the project should be ready for the prototype phase. However, if the

adapter is effective, the prototype phase should simply be an AFFS unit with the new

microcontroller and no other significant modifications.

The immediate overall goal for the future is to get a finished “AFFS 2.0” product to

JAARS as soon as possible while ensuring all requirements are met. Once the immediate goal is

achieved, additional communication interfaces such as the codan radio and satellite modem

could be considered for implementation in separate versions of the AFFS system. The exact

requirements/specs for these separate systems would need to be discussed with Mission

Aviation Fellowship (MAF) and United Indian Missions (UIM).

Conclusion

The Communications Group Flight Tracking and Messaging Systems team seeks to fulfill

the need for aircraft tracking in remote locations through the upgrade and expansion of the

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new microcontroller for the AFFS unit could not be completed at the present time. However,

since revising our project objective to focus on the upgrade of the AFFS system to AFFS 2.0, we

have made great progress and are almost ready to begin the final stages of this portion of the

project. Once all of the microcontroller code is ported and the test setup is ready, we will be

ready to finalize the design of the upgraded system. Although things didn’t always go smoothly

for the FTMS team this year, we’ve made some great strides toward a finished product. There

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Appendices

Figure 1: AFFS Communication Method

Figure 2: AFFS Satellite Modem Communication Method Figure 1: AFFS Communication Method

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Figure 3: Stellar ST2500 Satellite Modem

Flight Tracking and Messaging Systems