2. Background

In this section we define the Touchdown task and high-
light a preceding challenge of aligning and localising over

Figure 1: Outline of VLN as a supervised classification task a).
Linguistic and visual inputs both refer to entities indicated in red.
We address a challenge to align and localise over unsynchronised
inputs b) by focusing on entities represented in both modalities.
APriorityMapforVision-and-LanguageNavigation withTrajectoryPlansandFeature-LocationCues