A Calibration Method for Large-Footprint Full-Waveform Airborne Laser Altimeter without a Calibration Field

Li, Shaoning; Yu, Qiaojun; Fu, Anmin; Zhang, Guo

doi:10.3390/rs15112789

Cited by 1 publication

(1 citation statement)

References 21 publications

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“…However, this method is not suitable for satellites equipped with multiple instruments, such as the GaoFen-7 (GF-7), which includes a stereo mapping camera. Liu et al utilized a waveformmatching approach to calibrate laser altimeters by aligning the emitted laser waveform with the waveform reflected from the actual terrain [16,17]. Tang and associates introduced a laser altimetry satellite pointing calibration method reliant on terrain matching that does not require ground-based instruments and leverages digital surface model (DSM) data for calibrating the laser altimeter's pointing [18].…”

Section: Introductionmentioning

confidence: 99%

Fine Calibration Method for Laser Altimeter Pointing and Ranging Based on Dense Control Points

Xu,

Mo,

Wang

et al. 2024

Remote Sensing

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Satellite laser altimetry technology, a novel space remote sensing technique, actively acquires high-precision elevation information about the Earth’s surface. However, the accuracy of laser altimetry can be compromised by alterations in the satellite-ground environment, thermal dynamics, and cosmic radiation. These factors may induce subtle variations in the installation and internal structure of the spaceborne laser altimeter on the satellite platform, diminishing measurement precision. In-orbit calibration is thus essential to enhancing the precision of laser altimetry. Through collaborative calculations between satellite and ground stations, we can derive correction parameters for laser pointing and ranging, substantially improving the accuracy of satellite laser altimetry. This paper introduces a sophisticated calibration method for laser altimeter pointing and ranging that utilizes dense control points. The approach interpolates discrete ground control point data into continuous simulated terrain using empirical Bayesian kriging, subsequently categorizing the data for either pointing or ranging calibration according to their respective functions. Following this, a series of calibration experiments are conducted, prioritizing “pointing” followed by “ranging” and continuing until the variation in the ranging calibration results falls below a predefined threshold. We employed experimental data from ground control points (GCPs) in Xinjiang and Inner Mongolia, China, to calibrate the GaoFen-7 (GF-7) satellite Beam 2 laser altimeter as per the outlined method. The calibration outcomes were then benchmarked against those gleaned from infrared laser detector calibration, revealing disparities of 1.12 s in the pointing angle and 2 cm in the ranging correction value. Post validation with ground control points, the measurement accuracy was refined to 0.15 m. The experiments confirm that the proposed calibration method offers accuracy comparable to that of infrared laser detector calibration and can facilitate the updating of 1:10,000 topographic maps utilizing stereo optical imagery. Furthermore, this method is more cost-effective and demands fewer personnel for ground control point collection, enhancing resource efficiency compared to traditional infrared laser detector calibration. The proposed approach surpasses terrain-matching limitations when calibrating laser ranging parameters and presents a viable solution for achieving frequent and high-precision in-orbit calibration of laser altimetry satellites.

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Section: Introductionmentioning

confidence: 99%