The All-Weather Volcano Topography Imaging Sensor remote sensing instrument is a custom-built millimeterwave (MMW) sensor that has been developed as a practical field tool for remote sensing of volcanic terrain at active lava domes. The portable instrument combines active and passiveMMWmeasurements to record topographic and thermal data in almost all weather conditions from ground-based survey points.We describe how the instrument is deployed in the field, the quality of the primary ranging and radiometric measurements, and the postprocessing techniques used to derive the geophysical products of the target terrain, surface temperature, and reflectivity. By comparison of changing topography, we estimate the volume change and the lava extrusion rate. Validation of theMMWradiometry is also presented by quantitative comparison with coincident infrared thermal imagery.