Location Of Landing Site Research Articles

Correlation Network Analysis for Amino Acid Identification in Soil Samples With the ORIGIN Space-Prototype Instrument

The detection of biomolecules on Solar System bodies can help us to understand how life emerged on Earth and how life may be distributed in our Solar System. However, the detection of chemical signatures of life on planets or their moons is challenging. A variety of parameters must be considered, such as a suited landing site location, geological and environmental processes favourable to life, life detection strategies, and the application of appropriate and sensitive instrumentation. In this contribution, recent results obtained using our novel laser desorption mass spectrometer ORganics INformation Gathering Instrument (ORIGIN), an instrument designed for in situ space exploration, are presented. We focus in this paper on the detection and identification of amino acid extracts from a natural permafrost sample, as well as in an analogue mixture of soils and amino acids. The resulting dataset was analysed using a correlation network analysis method. Based on mass spectrometric correlation, amino acid signatures were separated from soil signatures, identifying chemically different molecular components in complex samples. The presented analysis method represents an alternative to the typically applied spectra-by-spectra analysis for the evaluation of mass spectrometric data and, therefore, is of high interest for future application in space exploration missions.

Child readers’ eye movements in reading Thai

It has recently been found that adult native readers of Thai, an alphabetic scriptio continua language, engage similar oculomotor patterns as readers of languages written with spaces between words; despite the lack of inter-word spaces, first and last characters of a word appear to guide optimal placement of Thai readers’ eye movements, just to the left of word-centre. The issue addressed by the research described here is whether eye movements of Thai children also show these oculomotor patterns. Here the effect of first and last character frequency and word frequency on the eye movements of 18 Thai children when silently reading normal unspaced and spaced text was investigated. Linear mixed-effects model analyses of viewing time measures (first fixation duration, single fixation duration, and gaze duration) and of landing site location revealed that Thai children’s eye movement patterns were similar to their adult counterparts. Both first character frequency and word frequency played important roles in Thai children’s landing sites; children tended to land their eyes further into words, close to the word centre, if the word began with higher frequency first characters, and this effect was facilitated in higher frequency words. Spacing also facilitated more effective use of first character frequency and it also assisted in decreasing children’s viewing time. The use of last-character frequency appeared to be a later development, affecting mainly single fixation duration and gaze duration. In general, Thai children use the same oculomotor control mechanisms in reading spaced and unspaced texts as Thai adults, who in turn have similar oculomotor control as readers of spaced texts. Thus, it appears that eye movements in reading converge on the optimal landing site using whatever cues are available to guide such placement.

High-Altitude Gas Balloon Trajectory Prediction: A Monte Carlo Model

The high-altitude gas balloon is an indispensable tool in atmospheric science, meteorology, and other applications requiring stratospheric observations. A prerequisite of the effectiveness of many types of balloon operations is an accurate trajectory forecasting capability. In particular, targeted flights, sample return missions, or flights of expensive instruments (whose recovery is essential) rely on such models. In this paper, the authors describe a new balloon flight simulation model, which takes into account a range of environmental, physical, and operational uncertainties to generate a predicted trajectory equipped with landing site location error estimates. A key source of error in such models is the incomplete understanding of the drag opposing the rise of balloons in the free atmosphere; here the authors propose a new stochastic drag model based on empirical data derived from thousands of radiosonde flights. Other sources of prediction error are also examined, affecting the accuracy of the flight-path forecast, such as uncertainties in the wind profile and balloon envelope manufacturing variability. The authors show how integrating these elements into a process that generates Monte Carlo ensembles of simulated trajectories has yielded a practically useful flight planning tool, which we have made available to the ballooning community as a free online service.

Using parallel line information for vision-based landmark location estimation and an application to automatic helicopter landing

An approach to landmark location estimation by computer vision techniques is proposed. The objective is to derive the position and the orientation of the landmark with respect to the vehicle by a single image. Such information is necessary for automatic vehicle navigation. This approach requires lower hardware cost and simple computation. The vanishing points of the parallel lines on the landmark are used to detect the landmark orientation. The detected vanishing points are used to derive the relative orientation between the landmark and the camera, which is then utilized to compute the landmark orientation with respect to the vehicle. The size of the landmark is used to determine the landmark position. Sets of collinear points are extracted from the landmark and their inter-point distances are computed. The positions of the collinear point sets are evaluated and used to determine the landmark position. Landing site location estimation by using the identification marking H on the helicopter landing site for automatic helicopter landing is presented as an application of the proposed approach. Simulations and experiments have been conducted to prove the feasibility of the proposed approach.