Songxin Tan

Bio: Songxin Tan is an academic researcher from South Dakota State University. The author has contributed to research in topics: Lidar & Computer science. The author has an hindex of 7, co-authored 17 publications receiving 191 citations. Previous affiliations of Songxin Tan include University of Nebraska–Lincoln & Sichuan University.

Design and performance of a multiwavelength airborne polarimetric lidar for vegetation remote sensing

Abstract: The University of Nebraska has developed a multiwavelength airborne polarimetric lidar (MAPL) system to support its Airborne Remote Sensing Program for vegetation remote sensing. The MAPL design and instrumentation are described in detail. Characteristics of the MAPL system include lidar waveform capture and polarimetric measurement capabilities, which provide enhanced opportunities for vegetation remote sensing compared with current sensors. Field tests were conducted to calibrate the range measurement. Polarimetric calibration of the system is also discussed. Backscattered polarimetric returns, as well as the cross-polarization ratios, were obtained from a small forested area to validate the system's ability for vegetation canopy detection. The system has been packaged to fly abroad a Piper Saratoga aircraft for airborne vegetation remote sensing applications.

Hybrid Problem-Based Learning in Digital Image Processing: A Case Study

Abstract: Contribution: This paper reports a curriculum development in hybrid problem-based learning (h-PBL), addresses the design, implementation, effectiveness, and assessment issues of h-PBL, and explains the mixed results observed regarding the impact of problem-based learning (PBL) on student grades from a hybrid perspective. Background: The effect of PBL on student learning is difficult to analyze. Empirical research on h-PBL has been scant in the engineering education field. Intended Outcomes: The hybrid approach described in this paper can be used to guide other course designs. Future research directions are also provided in order to better capture the positive effects of PBL on student learning. Application Design: A 3-D imaging project was developed and implemented using h-PBL. A non-parametric hypothesis test was conducted to compare four-year student performance data collected after the implementation of h-PBL with four-year student performance data collected under traditional lecturing; both sets of students were taught by the same instructor. Findings: Student project grades improved after h-PBL, whereas student cumulative course grades did not show significant improvement. The study suggests that higher ratios and weights of PBL, better timing in introducing PBL, and more integrated course components in the hybrid approach may further improve student performance.

A multiwavelength airborne polarimetric lidar for vegetation remote sensing: instrumentation and preliminary test results

Abstract: Several spaceborne and airborne lidar systems have been launched for vegetation canopy studies. Previous research has shown that lidars are useful tools for remote sensing of vegetation architecture. To support its Airborne Remote Sensing Program, the University of Nebraska has developed a multiwavelength airborne polarimetric lidar system. This system employs a Nd:YAG laser which emits radiation at two wavelengths: the fundamental at 1064 nm and the frequency-doubled at 532 nm. Both laser beams are highly linearly polarized (100:1 extinction ratio) and have a beam divergence angle of /spl sim/4 mrad. The receiver consists of four channels, which enable dual-wavelength and dual-polarization detection. In addition to the polarimetric information that could be gathered, this lidar system also has ranging capability and is able to record the whole lidar waveform. Thus, our lidar is capable of performing studies of vegetation canopy structure as well as characterization of vegetation depolarization. The system has been packaged to fly aboard a Piper Saratoga aircraft from a height of 1000 m. In this paper, we will present the details of the lidar system design, instrumentation, the system alignment and preliminary ground test results.

Polarized lidar reflectance measurements of vegetation at near-infrared and green wavelengths

Abstract: There is growing interest in the use of lidar for remote sensing of vegetation owing to the emergence of reliable and rugged lasers and highly sensitive detectors. Lidar remote sensing has a distinct advantage over conventional techniques in vegetation remote sensing due to its capability for three-dimensional characterization of vegetative targets. The Multiwavelength Airborne Polarimetric Lidar (MAPL) system was developed primarily for vegetation remote sensing applications from an airborne platform of up to 1,000 -m altitude. The lidar system has full waveform capture and polarimetric measurement capability at two wavelengths in the near-infrared (1064 nm) and the green (532 nm) spectral regions. This study presents preliminary ground-based lidar reflectance measurements on a variety of deciduous and coniferous trees under fully foliated conditions with a view towards tree species discrimination. Variations in the reflectance characteristics of selected deciduous trees under unfoliated and fully foliated conditions were also investigated. Our study reveals distinct differences in the reflectance characteristics of various trees.

Review of passive imaging polarimetry for remote sensing applications

Abstract: Imaging polarimetry has emerged over the past three decades as a powerful tool to enhance the information available in a variety of remote sensing applications. We discuss the foundations of passive imaging polarimetry, the phenomenological reasons for designing a polarimetric sensor, and the primary architectures that have been exploited for developing imaging polarimeters. Considerations on imaging polarimeters such as calibration, optimization, and error performance are also discussed. We review many important sources and examples from the scientific literature.

Full waveform hyperspectral LiDAR for terrestrial laser scanning

Abstract: We present the design of a full waveform hyperspectral light detection and ranging (LiDAR) and the first demonstrations of its applications in remote sensing. The novel instrument produces a 3D point cloud with spectral backscattered reflectance data. This concept has a significant impact on remote sensing and other fields where target 3D detection and identification is crucial, such as civil engineering, cultural heritage, material processing, or geomorphological studies. As both the geometry and spectral information on the target are available from a single measurement, this technology will extend the scope of imaging spectroscopy into spectral 3D sensing. To demonstrate the potential of the instrument in the remote sensing of vegetation, 3D point clouds with backscattered reflectance and spectral indices are presented for a specimen of Norway spruce.

The mind map book.

Abstract: Mind mapping is a thinking technique that nursing leaders can use to improve their decision-making and problem-solving abilities, and to better organise their ideas.