Radiometric Assessment of a UAV-Based Push-Broom Hyperspectral Camera

Area of Science:

• Remote Sensing
• Geospatial Science
• Instrument Calibration

Background:

• Unmanned aerial vehicles (UAVs) are increasingly used for Earth and environmental sensing.
• Hyperspectral imaging systems on UAVs require robust radiometric performance evaluation.
• Temporal and spatial stability data for UAV-based hyperspectral sensors are often limited.

Purpose of the Study:

• To develop and demonstrate a general protocol for evaluating the radiometric performance of push-broom hyperspectral cameras on UAVs.
• To assess the temporal and spatial consistency of dark current and white reference measurements.
• To determine the spectral fidelity and the relationship between sensor radiance and ground-based reflectance.

Main Methods:

• A protocol was developed for sensor evaluation, using the Nano-Hyperspec sensor as a case study.
• Dark current and white reference consistency were assessed over time and space.
• Spectral fidelity was evaluated using a mercury/argon lamp.
• The relationship between sensor-recorded radiance and spectroradiometer-derived reflectance was analyzed.

Main Results:

• Dark current and white reference showed minimal temporal increase (<2%) across most pixel-waveband combinations (>99.5%).
• Hyperspectral bands exhibited minor wavelength shifts (1-3 nm) compared to mercury/argon emission lines.
• A highly linear relationship was observed between Nano-Hyperspec radiance and spectroradiometer-derived reflectance.

Conclusions:

• The developed protocol effectively characterizes UAV-based hyperspectral sensor performance.
• The Nano-Hyperspec sensor demonstrated time-stable and spectrally sound radiometric performance.
• This methodology supports reliable data acquisition for Earth and environmental monitoring using UAVs.