Review of the development of digital earth research during 1998–2015 based on a bibliometric analysis

Since Al Gore created the vision for Digital Earth in 1998,a wide range of research in this field has been published in journals.However,little attention has been paid to bibliometric analysis of the literature on Digital Earth.This study uses a bibliometric analysis methodology to study the publications related to Digital Earth in the Science Citation Index database and Social Science Citation Index database(via the Web of Science online services)during the period from 1998 to 2015.In this paper,we developed a novel keyword set for‘Digital Earth’.Using this keyword set,11,061 scientific articles from 23 subject categories were retrieved.Based on the searched articles,we analyzed the spatiotemporal characteristics of publication outputs,the subject categories and the major journals.Then,authors’performance,affiliations,cooperation,and funding institutes were evaluated.Finally,keywords were examined.Through keyword clustering,research hotspots in the field of Digital Earth were detected.We assume that the results coincide well with the position of Digital Earth research in the context of big data.