Numerical simulation of the sensor output on Macao Science Satellite-1

Macao Science Satellite-1(MSS-1)will be launched at the early of 2023 into a near-circular orbit.The mission is designed to measure the Earth’s geomagnetic field with unpreceded accuracy through a new perspective.The most important component installed on the satellite,to ensure high accuracy,is the deployable boom(Optical Bench).A Vector Field Magnetometer(VFM),an Advanced Stellar Compass(ASC),and a Couple Dark State Magnetometers(CDSM)are deployed on the deployable boom.In order to maximize the mission’s scientific output,a numerical simulator on MSS-1’s deployable boom was required to evaluate the adaptability of all devices on the deployable boom and assist the satellite’s data pre-processing.This paper first briefly describes the synthesis of the Earth’s total magnetic field and then describes the method simulating the output of scalar and vector magnetometers.Finally,the calibration method is applied to the synthetic magnetometer data to analyze the possible noise/error of the relevant instruments.Our results show that the simulator can imitate the disturbance of different noise sources or errors in the measuring system,and is especially useful for the satellite’s data processing group.

Influences of various space current systems on the geomagnetic field in near-Earth space

Ground and space-based observations of the geomagnetic field are usually a superposition of different sources from the Earth’s core,lithosphere,ocean,ionosphere,and magnetosphere,and also from field-aligned currents coupling the ionosphere and magnetosphere—the meridional currents that connect the two hemispheres and the induced currents due to the variations of fields over time.The fluctuation of magnetic fields generated by these highly dynamic space currents greatly limits the accuracy of the geomagnetic models.In order to better accomplish the scientific objectives of Macao Science Satellite-1(MSS-1),and to improve existing geomagnetic field models,we present here for the first time a self-consistent coupling of solar wind,magnetosphere,and ionosphere,which represents the most developed numerical simulation method for space physics research so far,making it possible to quantify the contribution of different current systems to the total observed magnetic field(B).The results show that numerical simulation can capture main magnetic disturbance characteristics with significant precision.Partial ring current is a major contributor to the latitudinal magnetic perturbation near the equator.Magnetopause and magnetotail currents affect the radial magnetic perturbation around the mid-latitudes.Field-aligned and Pedersen currents produce significant longitudinal and latitudinal magnetic perturbations at high latitudes.

Rice domestication-associated transcription factor PROSTRATE GROWTH 1 controls plant and panicle architecture by regulating the expression of LAZY 1 and OsGIGANTEA,respectively

Plant architecture and panicle architecture are two critical agronomic traits that greatly affect the yield of rice(Oryza sativa).PROSTRATE GROWTH 1(PROG1)encodes a key C2H2-type zinc-finger transcription factor and has pleiotropic effects on the regulation of both plant and panicle architecture,thereby influencing the grain yield.However,the molecular mechanisms through which PROG1 controls plant and panicle architecture remain unclear.In this study,we showed that PROG1 directly binds the LAZY 1(LA1)promoter and acts as a repressor to inhibit LA1 expression.Conversely,LA1 acts as a repressor of PROG1 by directly binding to the PROG1 promoter.These two genes play antagonistic roles in shaping plant architecture by regulating both tiller angle and tiller number.Interestingly,our data showed that PROG1 controls panicle architecture through direct binding to the intragenic regulatory regions of OsGIGANTEA(OsGI)and subsequent activation of its expression.Collectively,we have identified two crucial targets of PROG1,LA1 and OsGI,shedding light on the molecular mechanisms underlying plant and panicle architecture control by PROG1.Our study provides valuable insights into the regulation of key domestication-related traits in rice and identifies potential targets for future high-yield rice breeding.

Negative feedback regulation of PROG1 in rice

Cultivated rice(Oryza sativa L.),one of the most widely grown and important crops worldwide,is believed to have been domesticated from the ancestral wild rice(Oryza rufipogon Griff.)thousands of years ago(Cheng et al.2003;Khush 1997;Fuller et al.2010).