\section{General Design Requirements \& Standards and Coordinate Systems}
\label{sec:interface}

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\subsection*{R-SC-AHEPaM-040: SI units}
\label{req:R-040}
The AHEPaM shall use the SI international system of units in accordance with ECSS-E-31C except where explicitly agreed with the Agency.

\paragraph{Justification:} 
Compliance.
\paragraph{Verification:}
Review of design documentation.

\paragraph{Comments:} 
None.

\paragraph{CAU Response:} 
The instrument design complies with the requirement.

%--------------------------------------------------------------------------------------------
\subsection*{R-SC-AHEPaM-041: Right-handed coordinate system}
\label{req:R-041}
The AHEPaM shall use only right-handed Cartesian coordinate systems.

\paragraph{Justification:} 
Compliance.
\paragraph{Verification:}
Review of cad model.
\paragraph{Comments:} 
None.
\paragraph{CAU Response:} 
The instrument design complies with the requirement.

%--------------------------------------------------------------------------------------------
\subsection*{R-SC-AHEPaM-043: Moments of Inertia}
\label{req:R-043}
The AHEPaM \ac{MoI} shall be determined referring to a coordinate system parallel to the AHEPaM\_PCS and with the origin at the AHEPaM \ac{CoG}.

\paragraph{Justification:} 
Compliance.
\paragraph{Verification:}
Review of cad model.
\paragraph{Comments:} 
None.
\paragraph{CAU Response:} 
The MoI values provided comply with the requirement.

%--------------------------------------------------------------------------------------------
\subsection*{R-SC-AHEPaM-330: Space environment}
\label{req:R-330}
The AHEPaM shall be compatible with the Space environment, as governed by [ATHENA - Environmental Specification].

\paragraph{Justification:} 
Compliance.
\paragraph{Verification:}
Analysis/ Test of specific requirements.

\paragraph{Comments:} 
None.
\paragraph{CAU Response:} 
AHEPaM is designed to comply with the given requirements.

%--------------------------------------------------------------------------------------------
\subsection*{R-SC-AHEPaM-341: Margin policy}
\label{req:R-341}
The AHEPaM shall conform to the margin policy described in [Margin Policy Document] during all development phases.

\paragraph{Justification:}
TBC compliance.

\paragraph{Verification:}
Review of design documentation.

\paragraph{Comments:} 
The document \textit{Margin Policy Document} which is stated in the requirement's description is not known to the interface team. Therefore compliance can't be stated. \newline
However the instrument team likes to comment that a design policy is applied which baselines ECSS-E-ST-10-02C Rev.1, 1 February 2018, Table 5-1. The detailed description can be found in \cite{ahepam-ddv}.

\paragraph{CAU Response:} 
\acs{TBC} compliant, after ESA's review of the the applied margin philosophy in \cite{ahepam-ddv}.
%--------------------------------------------------------------------------------------------
\subsection*{R-SC-AHEPaM-342: \acs{ECSS} Standards}
\label{req:R-342}
The AHEPaM shall conform to the published list of ESA approved \acf{ECSS} for the E, Q, and M branch.

\paragraph{Justification:} 
Compliance
\paragraph{Verification:}
Review of documentation referencing to the relevant \ac{ECSS} documents.

\paragraph{Comments:} 
None.
\paragraph{CAU Response:} 
Compliant.

%--------------------------------------------------------------------------------------------
\subsection*{R-SC-AHEPaM-343: Radiation design margin}
\label{req:R-343}

The AHEPaM shall use a \acf{RDM} factor 2 for the assessment of the Total Ionizing Dose effects. %Radiation Design Margin

\paragraph{Justification:} ESA-ATHENA-ESTEC-PL-SP-0001, ATHENA AHEPaM Specification

\paragraph{Verification:} Design/Analysis

\paragraph{Comments:} 

\paragraph{CAU Response:} We will use the state of the art space qualified microcircuits with the highest available radiation tolerance/rating.


%--------------------------------------------------------------------------------------------
\subsection*{R-SC-AHEPaM-346: MIL-STD-1553 IF}
\label{req:R-346}
The AHEPaM shall support the MIL-STD-1553 interface to/from the spacecraft.

\paragraph{Justification:} ESA-ATHENA-ESTEC-PL-SP-0001, ATHENA AHEPaM Specification

\paragraph{Verification:} Design/Analysis

\paragraph{Comments:} From specification document: "There are four different
interfaces, MIL-STD-1553, SpaceWire, CAN, Serial. MIL-STD-1553 is the baseline interface to the SC and the other three are offered as options."

\paragraph{CAU Response:} Unit uses Serial UART over LVDS as its standard communication interface and want to use it as one of the offered options in specification document.
A persistence of the use of MIL-STD-1553 will require an additional interface board in AHEPaM unit.