![](https://csdnimg.cn/release/download_crawler_static/87825187/bg12.jpg)
Remote Sens. 2018, 10, 1509
constraints [
5
]. This bridge has now been narrowed considerably, so one would expect researchers in
such regions to take advantage of this noble innovation.
This research set out to investigate whether the availability of such large amounts of data
at worldwide coverage, with free access (for research, education, and non-profit organizations)
to data processing algorithms and cloud computing facilities, had led to increased research in
less-developed nations, and whether researchers from these regions were embracing the opportunity.
Research publications from 2010 (establishment of GEE) onwards were searched for using the keyword
“Google Earth Engine” and all resulting publications were individually analyzed to record the origin
of the principal author’s affiliated institution, the origins of the affiliated institutions of all authors,
the primary study site, the scale of the study, the subject area, datasets used, and the number of
papers for each year of publication. The data was used to investigate patterns, authorship origins,
and whether there was a general take-up of opportunities in the less developed nations.
2. Materials and Methods
Google Scholar and Web of Science were used to search for all articles with
the words “Google Earth Engine” or “GEE” anywhere in the article, except in the
references section. All such articles were downloaded into Endnote (Clarivate Analytics,
1500 Spring Garden Philadelphia, PA 19130, USA
) and duplicates were then removed. Conference
papers, books and book chapters, audio-visual material, newspaper articles, reports, thesis, websites,
and abstracts from other sources were also discarded. A key reason for this was that the full versions
of these were generally not available to enable extractions of all required data. Patents and review
papers in journals were also removed. The remaining papers (journal articles) were manually
screened to identify the subject areas, study sites, the scale of the study (global, continental,
regional, country, or sub-country), number of authors, origin of the principal author’s affiliated
institution, the origins of the affiliated institutions of all authors, datasets used, and number of
papers per year. The information about author’s affiliated institutions was obtained from the
contact address on the manuscript. Where multiple addresses were given for an author, the first
address was used. It should be clarified that this research was not about the origin of authors but
where they were based when the research was conducted. The subject areas were quite varied,
so they were grouped into 16 broad categories. Data was analyzed in Excel and ArcGIS software
(ESRI, 380 New York Street Redlands, CA 92373-810, USA).
3. Results
The initial search resulted in 785 articles and, after screening for duplicates, 485 articles remained.
Of these, there was one audiovisual material, five books, 24 book sections, 66 conference proceedings,
two films or broadcasts, one newspaper article, 11 reports, 20 theses, one web page, one generic
material, 49 manuscripts where GEE was only mentioned in the references or was not in English or
was a review paper, and 304 were journal articles. From these 304 journal articles that had actually
used GEE in their research, four were either technical responses to other GEE related papers or
only mentioned GEE as a graphics interface from which other relevant data could not be extracted.
Thus 300 papers remained that were actual research papers published in journals between January
2010 and June 2017, which were then subjected to detailed analysis. The 300 journal papers were
published across 158 different journals, many of which had a single paper. The majority of the
papers were in Remote Sensing (32, IF: 3.41), Remote Sensing of Environment (19, IF: 6.46), Science of Total
Environment (8, IF: 4.61), PLoS ONE (
8, IF: 2.77
), IEEE Journal of Selected Topics in Applied Earth Observation
(
6, IF: 2.78
), International Journal of Remote Sensing (5, IF: 1.72), and Remote Sensing Applications—Society
and Environment (5, IF: NA). Applied Geography, Environmental Modelling and Software, Forest Ecology and
Management, International Journal of Digital Earth, ISPRS Journal of Geoinformation, Science, and Malaria
Journal had four papers each.
7