New Frontiers in GOES-R ABI Validation: A Feasibility Study for Using Near-Surface Unmanned Aircraft Systems

The heritage approach for reflective solar band (RSB) validation has demonstrated success in validating high to moderate resolution Earth imaging satellite sensors, which typically entails using handheld backpack spectrometers or instrumented ground sites to make ground reflectance measurements. Using this approach for environmental geostationary satellites sensors like the Advanced Baseline Imager (ABI) has limitations particularly with respect to spatial sampling and view geometry: the spatial and temporal sampling may not adequately represent the ~0.5 to 2 km-footprint of ABI, and fixing the geometry of the ground measurement (while covering large areas) to match the satellite view geometry is challenging. Other drawbacks of making such measurements are that they disturb the collection environment, are labor intensive, can be costly (typically involves a large team), and have limited repeatability. As a result of these limitations, NOAA has not utilized this approach operationally.

In support of extending this heritage approach towards NOAA’s next generation imager validation, an advanced capability development effort was initiated, “GOES-R near surface unmanned aircraft system (UAS) feasibility demonstration study” to mitigate these issues and meet the long-term challenges of validating next generation sensors. We report on the results of this 18-month study to design and develop the prototype systems, both rotary and fixed wing. The rotary system consists of hyperspectral reflective solar and broadband thermal infrared sensors, and a high-resolution context imager to generate products for ABI validation. The fixed wing system consisting of a camera and atmospheric sensor is used to create 2D high resolution georeferenced and orthorectified mosaics, digital elevation models, and atmospheric profiles providing detailed contextual information to complement the data products from the rotary system. We will discuss all aspects of the study from the design, characterization, and integration stages of development through functional and operation environment flight testing. The system and testing refinements throughout the development will be reviewed to highlight the lessons learned in this effort and discuss paths forward towards maturing this capability for operational use. These systems provide new capabilities to address significant validation gaps in the collection of reference data in support of environmental satellite products (L1b and L2+). Such systems have the potential to create a rapidly-deployable, affordable, flexible validation capability that builds off the heritage approaches and can meet the unique challenges of GOES-R ABI and other next generation satellite systems.