APPLEx

This project tests alternate configurations for remote sensing of soil moisture using a new state-of-the-art Active/Passive (ie radar/radiometer) P-/L-band (ie microwave) satellite concept through a series of airborne field experiments. Timely soil moisture information is critical to improved water management for food production in the face of climate variability. The challenge is to do this accurately over large areas with an appropriate spatiotemporal detail, and for a soil depth that closely approximates the layer which impacts crop/pasture growth and influences management decisions. The longer P-band allows deeper penetration into the soil while the active/passive combination uses the respective resolution and accuracy characteristics.

Soil moisture is a highly critical resource for the Australian agricultural economy which is stressed by climate change. Daily monitoring of paddock scale soil moisture from space represents a powerful tool to inform land management, allowing accurate crop yield and pasture growth predictions. At the continental scale, soil moisture information will result in better weather, climate and extreme flood prediction skill and the ability to assess effects of climate change on Australia. It is therefore critical that farmers and scientists have access to the soil moisture data they need, so the available water can be optimised for food production and the climate impacts better understood. This project lays the foundation for a new satellite capability to meet this need; successful demonstration of a combined L- and P-band Active and Passive sensing technology may lead to a dedicated satellite that would supersede the L-band SMOS (passive only) and SMAP (active and passive) satellites. It will also allow for operational soil moisture from the L-band NISAR and P-band BIOMASS active satellites soon to be launched.

Objectives:

1. Develop candidate soil moisture retrieval strategies that combine the active/passive L-/P-band data, including passive-passive, active-active, and active-passive methodologies and their combinations.
2. Select and test the optimal active/passive L-/P-band soil moisture retrieval strategie(s) in an airborne satellite simulation study over various land cover types.