Satellite Laser Altimetry. On-Orbit Calibration Techniques for Precise Geolocation.

Rowlands, D. D.; Carabajal, C. C.; Luthcke, S. B.; Harding, David J.; Sauber, Jeanne; Bufton, Jack L.

doi:10.2184/lsj.28.796

Cited by 13 publications

(9 citation statements)

References 3 publications

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“…It is important to continuously calibrate and validate laser data to eliminate or reduce uncertainties and to better provide high-precision products to the research community. A variety of in-orbit geometric calibration methods for laser altimeters have been proposed, including the scanning maneuver method, the ground detector method, and the terrain matching method [12]. The scanning maneuver method uses the ranging residuals (the difference between the measured data and the data calculated based on the ranging model) in spaceborne laser scanning data to estimate the pointing and ranging system bias [13,14].…”

Section: Introductionmentioning

confidence: 99%

Biases Analysis and Calibration of ICESat-2/ATLAS Data Based on Crossover Adjustment Method

et al. 2022

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The new-generation photon-counting laser altimeter aboard the Ice, Cloud, and Land Elevation Satellite-2 (ICESat-2) has acquired unprecedented high-density laser data on the global surface. The continuous analysis and calibration of potential systematic biases in laser data are important for generating highly accurate data products. Current studies mainly calibrate the absolute systematic bias of laser altimeters based on external reference data. There are few studies that focus on the analysis and calibration of relative systematic biases in long-term laser data. This paper explores a method for systematic biases analysis and calibration of ICESat-2 laser data based on track crossovers for the first time. In the experiment, the simulated data and ICESat-2 data were used to verify the algorithm. The results show that, during the three-year period in orbit, the standard deviation (STD) and bias of the crossover differences of the ICESat-2 terrain data were 0.82 m and −0.03 m, respectively. The simulation validation well demonstrate that the crossover adjustment can calibrate the relative bias between different beams. For ICESat-2 data, the STD of the estimated systematic bias after crossover adjustment was 0.09 m, and the mean absolute error (MAE) was 0.07 m. Compared with airborne lidar data, the bias and root mean square error (RMSE) of the ICESat-2 data remained basically unchanged after adjustment, i.e., −0.04 m and 0.38 m, respectively. This shows that the current ICESat-2 data products possess excellent internal and external accuracy. This study shows the potential of crossover for evaluating and calibrating the accuracy of spaceborne photon-counting laser altimeter data products, in terms of providing a technical approach to generate global/regional high-accuracy point cloud data with consistent accuracy.

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Section: Introductionmentioning

confidence: 99%

Biases Analysis and Calibration of ICESat-2/ATLAS Data Based on Crossover Adjustment Method

et al. 2022

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“…In terms of hardware, star sensors and cameras were used to detect the direction of laser emission in the GLAS system [17]. Meanwhile, many methods for laser pointing angle calibration have been developed [18]. For example, the range-residual calibration method was used, and it commanded that the spacecraft maneuver over the ocean and the range residuals were used to recover the pointing and range biases [19].…”

Section: Introductionmentioning

confidence: 99%

“…For example, the range-residual calibration method was used, and it commanded that the spacecraft maneuver over the ocean and the range residuals were used to recover the pointing and range biases [19]. Some methods have used known topography to calibrate the spaceborne laser altimeter [16,[20][21][22][23][24], and there have also been some methods to perform the calibration by analyzing the laser echo waveform [18]. A more direct kind of calibration method was performed by using the ground calibration site; a large number of sensor arrays were arranged in the site to measure the laser footprints, and the light spot center position was comprehensively analyzed to calibrate the pointing angle [25,26].…”

Section: Introductionmentioning

confidence: 99%

Iterative Pointing Angle Calibration Method for the Spaceborne Photon-Counting Laser Altimeter Based on Small-Range Terrain Matching

et al. 2019

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The satellite, Ice, Cloud and Land Elevation Satellite-2 (ICESat-2) has been equipped with a new type of spaceborne laser altimeter, which has the benefits of having small footprints and a high repetition rate, and it can produce dense footprints on the ground. Focusing on the pointing angle calibration of this new spaceborne laser altimeter, this paper proposes a fast pointing angle calibration method using only a small range of terrain surveyed by airborne lidar. Based on the matching criterion of least elevation difference, an iterative pointing angle calibration method was proposed. In the experiment, the simulated photon-counting laser altimeter data and the Ice, Cloud and Land Elevation Satellite-2 data were used to verify the algorithm. The results show that when 1 km and 2.5 km lengths of track were used, the pointing angle error after calibration could be reduced to about 0.3 arc-seconds and less than 0.1 arc-seconds, respectively. Meanwhile, compared with the traditional pyramid search method, the proposed iterative pointing angle calibration method does not require well-designed parameters, which are important in the pyramid search method to balance calculation time and calibration result, and the iterative pointing angle calibration method could significantly reduce the calibration time to only about one-fifth of that of the pyramid search method.

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“…One of the drawbacks in this space surveillance technique is the reliance on sunlight to provide the illumination. The emerging laser illumination technology [1,2,3] will allow active characterization. The laser-based tracking and imaging will result in better identification, large dynamic range and high resolution, as well as target discrimination with a range resolution of 1 mm and velocity of 10 cm/s for high velocity vehicles.…”

Section: Introductionmentioning

confidence: 99%

10 km dynamic laser oscillation with a coupled cavity assisted by four wave mixing

2012

SPIE Proceedings

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In this report, we present results of dynamic laser oscillation over a 10 km distance using a coupled-cavity structure assisted by four wave mixing (FWM). The system consists of a master cavity and a slave cavity that are coupled together through FWM in a nonlinear medium. The master and slave laser beams each form two arms of the four wave mixing structure. The master laser consists of a cavity formed by two highly reflective mirrors, in which there is a gain medium and the FWM nonlinear medium. For the slave laser cavity, one of the end mirrors is the grating formed inside the FWM medium, and the other mirror is the remote moving target. In this case, this target is a retro-reflector located on a moving airplane. The laser tracking was completed with a rotating gimbal mirror system that locked on the target. Successful lasing field tests at distances over 10 km have been achieved, and further results can potentially be obtained at longer distances. The laser oscillations are free running with a pump pulse width of 2-5 milliseconds. Based on the time separations between the pulses from the master and slave cavities, the target distance can be precisely calculated.

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Satellite Laser Altimetry. On-Orbit Calibration Techniques for Precise Geolocation.

Cited by 13 publications

References 3 publications

Biases Analysis and Calibration of ICESat-2/ATLAS Data Based on Crossover Adjustment Method

Biases Analysis and Calibration of ICESat-2/ATLAS Data Based on Crossover Adjustment Method

Iterative Pointing Angle Calibration Method for the Spaceborne Photon-Counting Laser Altimeter Based on Small-Range Terrain Matching

10 km dynamic laser oscillation with a coupled cavity assisted by four wave mixing

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