Algorithm 1 The GP-PHD algorithm

Input:  ${\left\{w_{t-1}^a,m_{t-1}^a,P_{t-1}^a\right\}}_{a=1}^{J_{t-1}}$, $Z_t$, $T_p$, $T_o$  1:Predict  2:(1) predict newborn targets  3:$a=0$  4:for  $j=1:J_{\gamma ,t}$  do  5:   $a=a+1$  6:   $w_{t\left|t-1\right.}^i=w_{\gamma ,t}^j$, $m_{t\left|t-1\right.}^i=m_{\gamma ,t}^j$, $P_{t\left|t-1\right.}^i=P_{\gamma ,t}^j$  7:end for  8:(2) predict existing targets  9:for  $j=1:J_{t-1}$  do 10:   $a=a+1$ 11:   use (29)–(33) calculate the predictive parameters $m_{s,t\left|t-1\right.}^j$ and $P_{s,t\left|t-1\right.}^j$ for the birth targets 12:end for 13:$J_{t\left|t\right.-1}=i$ 14:Update 15:for  $j=1:J_{t\left|t\right.-1}$  do 16:   $w_t^a=\left(1-p_{d,t}\right)w_{t\left|t-1\right.}^a$, $m_t^a=m_{t\left|t-1\right.}^a$, $P_t^a=P_{t\left|t-1\right.}^a$ 17:end for 18:$q=0$ 19:for  $b=1:length\left(Z_t\right)$  do 20:   $q=q+1$ 21:   for $j=1:J_{t\left|t\right.-1}$ do 22:       $w_t^j=p_{d,t}{w}_{t\left|t-1\right.}^j{q}_t^j\left(z\right)$ 23:       use (36), (38)–(48) calculate the update parameters $m_{t\left|t\right.}^j$ and $P_{t\left|t\right.}^j$ 24:   end for 25:   use (37) calculate the update parameters $w_t^j$ 26:end for 27:$J_t=q{J}_{t\left|t-1\right.}+J_{t\left|t-1\right.}$ Output:  ${\left\{w_t^i,m_t^i,P_t^i\right\}}_{i=1}^{J_t}$