대한민국 해군 세종대왕급 이지스 구축함(DDG) SPY-1D(V) 다기능 위상배열 레이다 종말 다중표적 요격 지령 송신 및 1,000Hz 0-Alloc C# 실시간 업링크 스케줄러 엔진

using System;
using System.Numerics;
using System.Runtime.CompilerServices;

namespace ZeliDesk.Defense.Navy.Aegis
{
    public readonly record struct MissileTrack(
        int MissileId,
        Vector3 Position,
        Vector3 Velocity,
        int TargetId,
        float TimeToIntercept
    );

    public readonly record struct TargetTrack(
        int TargetId,
        Vector3 Position,
        Vector3 Velocity,
        bool IsBallisticThreat
    );

    public ref struct UplinkCommandFrame
    {
        public int MissileId;
        public Vector3 AccelerationCmd;
        public float TargetPredictedRange;
        public byte SubcarrierChannel;
        public bool MidcoursePulseAck;
    }

    public static class AegisSpy1dInterceptionUplinkEngine
    {
        private const float NavigationConstant = 3.5f; // N'
        private const float SpeedOfLight = 299792458.0f; // m/s
        private const float CarrierFrequency = 3.3e9f; // S-Band 3.3 GHz

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static int ScheduleUplinkBatch(
            ReadOnlySpan<MissileTrack> missiles,
            ReadOnlySpan<TargetTrack> targets,
            Span<UplinkCommandFrame> outputFrames)
        {
            int frameCount = 0;
            int maxFrames = Math.Min(missiles.Length, outputFrames.Length);

            for (int i = 0; i < maxFrames; i++)
            {
                ref readonly var m = ref missiles[i];
                
                // 표적 추적 데이터 매칭
                int targetIdx = -1;
                for (int t = 0; t < targets.Length; t++)
                {
                    if (targets[t].TargetId == m.TargetId)
                    {
                        targetIdx = t;
                        break;
                    }
                }

                if (targetIdx < 0) continue;
                ref readonly var tgt = ref targets[targetIdx];

                // 상대 기하 벡터 계산
                Vector3 r = tgt.Position - m.Position;
                float distSq = r.LengthSquared();
                float dist = MathF.Sqrt(distSq);

                if (dist < 1.0f) dist = 1.0f;

                Vector3 rHat = r / dist;
                Vector3 vRel = tgt.Velocity - m.Velocity;

                // 접근 속도 Vc = - (r dot vRel) / dist
                float vClosing = -Vector3.Dot(r, vRel) / dist;

                // 시선 각속도 벡터 w = (r x vRel) / |r|^2
                Vector3 omegaLos = Vector3.Cross(r, vRel) / distSq;

                // 비례항법 가속도 지령 ac = N' * Vc * (omega x rHat)
                Vector3 aCmd = NavigationConstant * vClosing * Vector3.Cross(omegaLos, rHat);

                // 고G 기동 한계 클램핑 (SM-6 최대 35G)
                float maxAccel = 35.0f * 9.80665f;
                float aCmdMag = aCmd.Length();
                if (aCmdMag > maxAccel)
                {
                    aCmd = aCmd * (maxAccel / aCmdMag);
                }

                // 업링크 프레임 할당
                outputFrames[frameCount] = new UplinkCommandFrame
                {
                    MissileId = m.MissileId,
                    AccelerationCmd = aCmd,
                    TargetPredictedRange = dist,
                    SubcarrierChannel = (byte)(m.MissileId % 16),
                    MidcoursePulseAck = true
                };
                frameCount++;
            }

            return frameCount;
        }
    }
}