Showing papers in "Advances in Space Research in 2022"

TL;DR: In this article , a unified neural control scheme is presented for the output-constrained trajectory tracking of space manipulator under unknown parameters and external perturbations, by utilizing the backstepping control technique as the main framework, the proposed controller is developed with the help of neural network (NN) and tan-type barrier Lyapunov function (BLF).

TL;DR: In this paper , the authors analyzed the scientific exploration tasks of CE-5 mission conducted on the lunar surface, and carried out the scientific payload system architecture design and individual scientific payload design with the scientific task requirements as the target, and proposed the working mode and main technical index requirements of the payloads.

TL;DR: In this article , active surface deformation, displacement pattern, and erosional variability are estimated using the geomorphologically sensitive morphometry along with the Persistent Scatterer Interferometric Synthetic Aperture Radar (PSInSAR) technique using the Sentinel-1Adata (119 images) acquired between 07- 02-2017 and 10-02-2021.

TL;DR: In this paper , a formation potential is defined to derive a formation control law for virtual structure, which enables multiple spacecraft to maintain polygonal or tetrahedral formation and avoid collision with obstacles.

TL;DR: In this article , the performance of three different machine learning algorithms to map soil salinity using Landsat-8 OLI, Sentinel-2A satellite images, and ground-based electrical conductivity (EC) measurements with the aid of Google Earth Engine platform was analyzed.

TL;DR: In this paper , the performance of deep learning models such as Long Short-Term Memory (LSTM) and a recently proposed Gated Recurrent Unit (GRU) in forecasting the ionospheric GPS-VTEC, and compare the performance with that of Multilayer Perceptron (MLP) neural networks, GIM_TEC and the IRI-Plas 2017 models.

TL;DR: In this paper , the authors investigated the possibility of high resolution mapping of PM2.5 concentration over Tehran city using high resolution satellite AOD (MAIAC) retrievals and proposed a framework including three main stages, data preprocessing; regression modeling; and model deployment.

TL;DR: In this paper , the authors compared the utility of multispectral data for land-cover classification of Mumbai city and its nearby regions with a special focus on water body mapping, using the dual-frequency L and S-band NASA-ISRO Synthetic Aperture Radar (NISAR) mission.

TL;DR: In this paper , a stacked LSTM forecasting model was used to predict the strength and peak time of solar cycle 25 by employing the monthly smoothed sunspot number data obtained from WDC-SILSO, Royal Observatory of Belgium, Brussels.

TL;DR: The NASA InSight lander mission to Mars payload includes the Heat Flow and Physical Properties Package HP3 to measure the surface heat flow as mentioned in this paper , which was designed to use a small penetrator -named the mole -to implement a vertical string of temperature sensors in the soil to a depth of 5 m. Unfortunately, the mole did not penetrate more than 40 cm, roughly a mole length.

TL;DR: In this article , the authors summarize all of the SEP models currently developed in the scientific community, including a description of model approach, inputs and outputs, free parameters, and any published validations or comparisons with data.

TL;DR: In this paper , the authors presented the results of detail investigation of active ground subsidance in New Delhi, National Capital Region (NCR) using multiple SAR sensor data and exploited the PS-InSAR technique.

TL;DR: In this article , a novel bounded barrier Lyapunov function (BBLF) is proposed to solve the singularity and infinite control effort problem once the constraints are not satisfied because of the actuator failure or other disturbance.

TL;DR: In this article , the authors provided the first-time comprehensive evaluation of 12 advanced statistical and machine learning (ML) algorithms for the Soil Moisture (SM) estimation from dual polarimetric Sentinel-1 radar backscatter.

TL;DR: In this article , the authors performed the polarimetric calibration of the Quad-pol and Compact-pol datasets acquired using different airborne and spaceborne PolSAR systems to estimate and minimize these polar-imetric distortions.

TL;DR: The initial assessment of the China BeiDou global navigation satellite system (BDS-3) PPP-B2b products and the PPP performance over a period of near five months from Jul 26, 2020 to Dec 19, 2020 was carried out in this article .

TL;DR: In this paper , the performance of hybrid genetic algorithm (GA) optimization method and Extreme Gradient Boosting (XGB) model was evaluated for predicting flood susceptibility in Tafresh watershed in Markazi Province, Iran based on KNN, XGB and GA-XGB models.

TL;DR: Park et al. as mentioned in this paper proposed a multi-scale, multi-task CNN which consists of a shared multiscale feature encoder and multiple prediction heads that perform different tasks on a shared feature output.

TL;DR: In this article , the authors examined the urban heat island (UHI) phenomena in the Kolkata metropolitan area and its surrounding rural areas based on MODIS satellite data of the last two decades (2001-19).

TL;DR: In this paper , the authors compared the performance of Random Forest (RF) and Ordinary Least Squares (OLS) regression models over agricultural areas of Rupnagar district of Punjab in India.

TL;DR: In this paper , a neural network-based optimal mixed H2/H∞ control for a modified UAV to accomplish trajectory tracking missions is presented, where H∞ attenuates the effect of uncertainties and through H2 the consumed control energy is minimized.

TL;DR: In this paper , a deep multi-layer perceptron network named DMLP-LSM was proposed to generate landslide susceptibility maps (LSM) by using the 1D LOS velocity map as a thematic layer.

TL;DR: In this article , the authors explore how subjectivity affects the 3D CME parameters that are obtained from the GCS reconstruction technique, and they have designed two different synthetic scenarios where the ''true'' geometric parameters are known in order to quantify such uncertainties for the first time.

TL;DR: In this paper , two nonparametric machine learning algorithms viz Support Vector Machines (SVMs) with different kernel functions were employed for the prediction of above ground biomass using different combinations of VV, VH, Normalized Difference Vegetation Index (NDVI) and Incidence Angle (IA).

TL;DR: In this article , the authors analyzed data collected at 8 high-latitude GNSS stations to validate the performance of the phase scintillation index (σϕ) statistically.

TL;DR: In this article , a constrained hypersonic reentry trajectory optimization problem is formulated and solved using a hybrid algorithm, where the initial solution generation efficiency and global optimality are enhanced by applying the Tent chaotic sequence mapping and the golden sine update strategy.

TL;DR: In this paper , the authors considered the contactless transportation of space debris by means of an ion beam generated by an active spacecraft electrodynamic engine and developed a control of the engine thrust, which ensured the stabilization of spatial oscillations of cylindrical space debris.

TL;DR: In this paper , the dynamic equations of flexible-link manipulators with revolute-prismatic joints were derived by using Hamilton's principle with the assumption of nonlinear strains and the discretized motion equations were solved and the results were presented in the forms of bifurcation diagrams (for variation of torque/force amplitude), Poincaré maps, phase-plane portraits, and the largest Lyapunov exponent.

TL;DR: In this article , the authors explore the use of lunar and Martian regoliths to create construction materials with properties suitable for such structures as landing pads, and offer a robust framework for comparing performance of different simulants under the same curing protocols and environmental exposures, as well as offering insight as to the effects of vacuum curing, and exposure to high and low temperature environments on cured binder samples.

TL;DR: In this article , an overview is presented on three aspects of using local materials in lunar construction activities: nature of in-situ soils obtained with lunar missions, the variety of lunar soil simulants produced on Earth, and their use in producing lunar construction materials.