  Given a network of receivers and transmitters, the process of determining
their positions from measured pseudoranges is known as network
self-calibration. In this paper we consider 2D networks with synchronized
receivers but unsynchronized transmitters and the corresponding calibration
techniques, known as Time-Difference-Of-Arrival (TDOA) techniques. Despite
previous work, TDOA self-calibration is computationally challenging. Iterative
algorithms are very sensitive to the initialization, causing convergence
issues. In this paper, we present a novel approach, which gives an algebraic
solution to two previously unsolved scenarios. We also demonstrate that our
solvers produce an excellent initial value for non-linear optimisation
algorithms, leading to a full pipeline robust to noise.
