Exploring MODIS band 23 for urban remote sensing: Seasonal and view angle effects

Spanning 3–5 microns, the middle infrared (MIR) region (3–5μm) of the electromagnetic spectrum has received little attention in terrestrial remote sensing. Here we explore the potential of MIR for urban remote sensing. We focus on MODIS band 23 (4.02–4.08 μm) at a spatial resolution of 1 km. By capturing both the solar reflectance and terrestrial emittance, the MIR offers some new approaches for monitoring urban areas. We are interested in the seasonal contrast created by MIR-dark vegetation and MIR-bright impervious surfaces, which allow urban areas to emerge from the surrounding vegetated landscape. We found (1) Viewing geometry and (2) land surface phenology (LSP) due to distinct spectral characteristics of impervious surfaces and vegetation to be two major influences on the dynamics of MIR brightness. Analyzing the dynamics of MIR brightness in relation to seasonal and view angle effects, is a key consideration for future image processing and compositing, urban morphology monitoring, and analysis.