# Research Progress of Dynamic Measurement Technology of Atom Gravimeter
## 1 Introduction  
With the advent of laser cooling technology in the 1980s, scientists were able to capture and manipulate originally \"active\" atoms. In 1991, the [PERSON] research team at Stanford University realized an atom interferometer for the first time by using the method of stimulated Raman transition [1]. For more than 30 years, atom interference technologies have developed rapidly. At present, more than 50 research groups in the world have devoted themselves to the research of atom interferometers. It is widely used in the fields of navigation [2; 3], metrology [4; 5], gravitational wave detection [6], and general relativity verification [7; 8]. Among them is the most in-depth and representative research on the use of atom interference technology for gravity measurement, i.e., the atom gravimeter. The atom gravimeter measures the absolute gravity value. Compared with the relative gravimeter with a straight-pull or zero-length spring, there is no mechanical wear, no drift, and no need for periodic correction. Compared with the optical interference absolute gravimeter, its wavelength is much shorter, so it has higher potential sensitivity and accuracy according to the relationship between the wavelength of matter waves and particle momentum [9]. Atomic gravimeters are expected to surpass relative gravimeters and optical interference gravimeters to become the next generation of high-precision absolute gravity sensors [10; 11; 12]. In the early days of the development of atom gravimeters, various research teams devoted themselves to improving the sensitivity, accuracy, and stability of the system in the laboratory environment. For example, when [PERSON]'s team demonstrated the atom interferometer for the first time, it was used to measure gravity. The Raman light intervaltime \(T\) was 10 ms, and the measurement resolution was 3 mGal (1000 s) [1]. In 2001, the team developed the second-generation instrument, and its performance greatly improved. Under the condition of \(T\) being 160 ms, the fountain-type atom gravimeter was realized by using a cesium atom cloud with a sensitivity of 20 \(\upmu\)Gal/Hz\({}^{1/2}\) and a resolution of 0.1 \(\upmu\)Gal (48 h). The system error and noise source were analyzed in detail, and the comprehensive uncertainty was 3.4 \(\upmu\)Gal [13]. In 2008, cesium atoms were continued to be used under the condition of a longer Raman interval time (400 ms), and the measurement sensitivity was 8 \(\upmu\)Gal/Hz\({}^{1/2}\)[14]. Huazhong University of Science and Technology has been conducting research on atom gravimeters in cave laboratories since 2006, with the goal of achieving a sensitivity of 1 \(\upmu\)Gal/Hz\({}^{1/2}\)[15]. In 2013, the team used a two-dimensional magneto-optical trap to increase the number of atoms, improve the signal-to-noise ratio, use a better optical phase-locked loop to reduce the phase noise of Raman light, and combine it with an active vibration isolation system to obtain a sensitivity of 4.2 \(\upmu\)Gal/Hz\({}^{1/2}\)[16]. In addition, there are many research teams dedicated to the study of atom gravimeters. Table 1 lists some of the reported static measurement results of high-precision atom gravimeters. In recent years, research teams have paid more attention to the integration and miniaturization of devices. For example, in 2010, [PERSON] et al. proposed a miniaturization scheme using a pyramid mirror to achieve atomic capture, state selection, interference, detection, and other functions with a single laser beam. This scheme greatly reduced the complexity and volume of the system. The sensitivity of the system was 170 \(\upmu\)Gal/Hz\({}^{1/2}\)[27]. Inspired by this, some teams have adopted a similar structure to design atom gravimeters [22,28]. In 2014, [PERSON] et al. improved the magnetic shielding coil of the atom gravimeter to replace the traditional metal shield and adopted a relatively small portable vibration isolation platform, which provided a new realization method for field measurement.