  In the trace reconstruction problem an unknown string ${\bf
x}=(x_0,\dots,x_{n-1})\in\{0,1,...,m-1\}^n$ is observed through the deletion
channel, which deletes each $x_k$ with a certain probability, yielding a
contracted string $\widetilde{\bf X}$. Earlier works have proved that if each
$x_k$ is deleted with the same probability $q\in[0,1)$, then $\exp(O(n^{1/3}))$
independent copies of the contracted string $\widetilde{\bf X}$ suffice to
reconstruct $\bf x$ with high probability. We extend this upper bound to the
setting where the deletion probabilities vary, assuming certain regularity
conditions. First we consider the case where $x_k$ is deleted with some known
probability $q_k$. Then we consider the case where each letter $\zeta\in
\{0,1,...,m-1\}$ is associated with some possibly unknown deletion probability
$q_\zeta$.
