What do you think was done right on the below syystem architecture and functional description? Any positive notes or suggestions? Proposed Project Overview

My proposed project is Best Glide Ratio System $($BGRS$).$ BGRS is a system that reduces pilot workload during emergency descents by using the current Global Positioning Satellite $($GPS$)$ data to determine aircraft altitude and ground speed to provide a sorted list of reachable airfields. Additionally, it provides a countdown of remaining time in the air.

System Architecture

BGRS system architecture is depicted in Figure $1.$ The system requires a lock with four GPS satellites to derive aircraft $3-$D positional data. This is depicted in the upper right corner. The system consists of a GPS antenna, coaxial cable, and a head unit. The head unit contains, a switchable power supply which is capable of operating the unit from either $14$ volts direct current $($VDC$)$ or $28$ VDC$.$ This is necessary as general aviation aircraft can have either $14$ VDC or $28$ VDC electrical systems. This will satisfy the BGRS constraint requirement BGRS$-01,$ BGRS shall be capable of using $14$ Volts Direct Current of $28$ VDC Power.

The power supply provides the necessary power for the remaining boards within the head unit. A GPS receiver within the head unit provides the interface to the antenna and provides digital I$/$O to the processor board. The processor board contains the CPU and volatile and non$-$volatile memory necessary for BGRS operation. The processor board provides display I$/$O to the display processor which is responsible for producing the display graphics. The display board outputs video to the display board and responds to inputs from the operator such as manually initiated Built$-$In$-$Test, airfield selection, on$/$off selection, and other inputs.

Lastly, the system contains a maintenance interface connector on the head unit for programming GPS almanac data. This database contains vital airfield information such as longitude, latitude, and elevation as well as the airfield International Civil Aviation Organization $($ICAO$)$ codes. Sofware running on the processor board uses this data to calculate the nearest reachable airfield$($s$).$

Figure $1$ BGRS System Architecture

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Architecture Relationship with Requirements

As previously noted, a selectable power supply addresses the constraint requirement related to power. The head unit contains a GPS received which addresses the system functional requirement BGRS$-02,$ BGRS shall utilize Global Positioning Satellite $($GPS$)$ data for calculations. The head unit contains both hardware and software to address various functional and operational requirements. A few $($not inclusive of all requirements$)$ are listed below:

Requirement No$.$ Requirement Type

BGRS$-03$ BGRS shall display the message "AIRFIELD NOT REACHABLE" in red font when an airfield cannot be reached. Functional

BGRS$-04$ BGRS shall update display data at $5$ Hz$.$ Performance

BGRS$-05$ BGRS shall execute a Start$-$up Built in Test $($S$-$BIT$)$ at power on$.$ Functional

BGRS$-06$ BGRS shall provide a method for the operator to command a Manual BIT $($M$-$BIT$).$ Functional

BGRS$-07$ BGRS shall complete S$-$BIT in less than $1$ minute. Performance

BGRS$-08$ BGRS shall display a near english message for BIT failures Functional

BGRS$-09$ BGRS shall display a total time remaining in the air in hours, minutes, and seconds format. Functional

BGRS$-10$ BGRS shall display a sorted list of reachable airfields. Functional

BGRS$-11$ BGRS shall start time remaining in air and nearest airfield calcuations when commanded by the operator. Functional

BGRS$-12$ BGRS shall allow the operator to select a different destination when multiple airfields are available. Functional

BGRS$-13$ BGRS shall provide a track to the selected airfield. Functional

BGRS$-14$ BGRS shall display the message $"$GPS NOT AVAILABLE" in red font when fewer then four GPS satellites are locked. Functional