function [guideAccel] = getGuidance(Mt,missileState,targetState)
% This function computes the acceleration command to the missile required to
% intercept a target
missileState = missileState(:);
targetState = targetState(:);

% Compute proportional navigation (PN) guidance command
PNGain = 0; % PN guidance gain
terminalPNGain = 4;
KVP = 0.5;
blindRng = 2; %Seeker blind range (m)
acqRng = 5000; % Acquisition Range (m)
g = 9.8066; % Acceleration due to gravity (m/sec^2)
gLimit = 40.; % Lateral acceleration limit in gees
relState = targetState - missileState;
relRng = relState(1:3);
relVel = relState(4:6);
mslVel = missileState(4:6);
% Velocity pursuit guidance
if Mt>0.5
    nHat = cross(mslVel,relRng);
    accelCmdVP = KVP*cross(nHat,mslVel/norm(mslVel))/norm(relRng);
else
    accelCmdVP = [0; 0; 0];
end
if norm(accelCmdVP)>gLimit*g
    accelCmdVP = gLimit*g*accelCmdVP/norm(accelCmdVP);
end
% LOSR is line-of-sight rate
LOSR = cross(relRng,relVel)/dot(relRng,relRng);
if norm(relRng)<acqRng
    PNGain = terminalPNGain;
    accelCmdVP = [0; 0; 0];
end
%accelCmd = -PNGain*norm(relVel)*cross(relRng/norm(relRng),LOSR);
accelCmd = -PNGain*norm(relVel)*cross(mslVel/norm(mslVel),LOSR);
if norm(accelCmd)>gLimit*g
    accelCmd = gLimit*g*accelCmd/norm(accelCmd);
end
guideAccel = accelCmd + accelCmdVP;
if norm(relRng)<blindRng
    guideAccel = [0;0;0];
end
end