## 1 Introduction  
Glacier mass balance plays a critical role in changes in the surrounding water resources, sea level rise, atmospheric circulation, etc., and is closely related to regional economic development and social stability [1; 2; 3; 4]. The glaciers of the southeastern Tibetan Plateau (SETP) are located in the southeastern part of the Qinghai-Tibet Plateau, known as the \"roof of the world\", and are an important water source for the Yarlung Zangbo River, Nujiang River, Ganges River, and Lancangjiang River. In recent decades, with the increase in global temperatures, coupled with the influence of the hot and humid Indian Ocean monsoon, SETP glaciers have been rapidly melting which has resulted in large-scale glacier mass loss [3; 4; 5; 6]. Due to the lack of large-scale, high-resolution, and high-precision observations, the knowledge on the spatial distribution of the glacier mass balance and the response to climate change in this region is limited. Glacier mass balance in the SETP has been a hotspot of glaciological research. The methods for glacier mass balance monitoring in the published literature include direct field surveys, modeling (e.g., energy balance), indirect estimations (e.g., from length and area surveys), and estimations using satellite altimetry or gravimetry. For the field surveys and modeling method, [PERSON] et al. and [PERSON] et al. used the energy mass balance method to obtain the mass balance of several glaciers, including the 24K glacier and Parlung No. 94 glacier in this region; the results showed that the glaciers were in a state of rapid melting [7,8]. For the indirect estimation method, measuring changes in glacier area and/or length can indicate changes in its mass balance. [PERSON] et al., [PERSON] et al., [PERSON] et al., [PERSON] et al., [PERSON] et al., and [PERSON] et al. monitored the glacier area changes of Hailuogou glacier, Buga Gangri Icefield, and Yalong glacier in the SETP using optical remote sensing data. According to their results, most glaciers have been in retreat in the recent decades [9, 10, 11, 12, 13, 14]. However, all of the aforementioned methods, either through modeling or observations, can only indirectly indicate the changes in glacier mass balance. For the method of estimations using satellite altimetry, [PERSON] et al., [PERSON] et al., and [PERSON] et al. directly estimated glacier mass balance in the SETP by using ICESat satellite altimetry data from 2003 to 2009, and found that the rate of glacier surface elevation change was \(-\)0.30 \(\pm\) 0.13 m/yr, \(-\)0.81 \(\pm\) 0.32 m/yr, and \(-\)1.34 \(\pm\) 0.29 m/yr, respectively [15, 16, 17]. For the method of estimations using optical remote sensing, [PERSON] et al. estimated the mass balance of glaciers in the SETP using SPOT-5 optical remote sensing stereo pairs from 2000 to 2011, yielding a glacier surface elevation change rate of \(-\)0.39 \(\pm\) 0.16 m/yr [5]. [PERSON] et al. used ASTER optical stereo pairs data from 2000 to 2016 to estimate the glacier mass balance, obtaining a value of \(-\)0.73 \(\pm\) 0.23 m/yr [18]. Recently, [PERSON] et al. used ASTER stereo image pairs to obtain the mass balance of glaciers in the SETP during 2000-2020, yielding a glacier surface elevation change rate of \(-\)0.66 \(\pm\) 0.02 m/yr [19]. For the method of estimations using DEM products, [PERSON] et al. used the 90 m resolution TanDEM-X DEM product released by the German Aerospace Center (DLR) to obtain glacier mass balance results from 2000 to 2013 for the central and eastern Nyquistenglha, located in the SETP, and found a glacier mass balance rate of \(-\)4.11 \(\pm\) 1.52 Gt/yr [20]. Although satellite altimetry provides direct measurements about the changes in ice volume, several approximations are necessary to translate these observations into changes in glacier mass balance. Gravimetric surveys, on the other hand, measure changes in mass directly. Thus, after filtering for confounding factors, they can provide direct information on glacier mass balance. [PERSON] et al.