journal of computer Cohen, A, et al. 2020. Ethics in Archaeological Lidar. applications in archaeology Journal of Computer Applications in Archaeology, 3(1), pp. 76–91. DOI: https://doi.org/10.5334/jcaa.48 POSITION PAPER Ethics in Archaeological Lidar Anna Cohen*, Sarah Klassen† and Damian Evans‡ Airborne laser scanning or lidar has now been used by archaeologists for twenty years, with many of the first applications relying on data acquired by public agencies seeking to establish baseline elevation maps, mainly in Europe and North America. More recently, several wide-area acquisitions have been designed and commissioned by archaeologists, the most extensive of which cover tropical forest environments in the Americas and Southeast Asia. In these regions, the ability of lidar to map microtopographic relief and reveal anthropogenic traces on the Earth’s surface, even beneath dense vegetation, has been welcomed by many as a transformational breakthrough in our field of research. Nevertheless, applications of the method have attracted a measure of criticism and controversy, and the impact and significance of lidar are still debated. Now that wide-area, high-density laser scanning is becoming a standard part of many archaeologists’ toolkits, it is an opportune moment to reflect on its position in contemporary archaeo- logical practice and to move towards a code of ethics that is vital for scientific research. The papers in this Special Collection draw on experiences with using lidar in archaeological research programs, not only to highlight the new insights that derive from it but also to cast a critical eye on past practices and to assess what challenges and opportunities remain for developing codes of ethics. Using examples from a range of countries and environments, contributions revolve around three key themes: data management and access; the role of stakeholders; and public education. We draw on our collective experiences to propose a range of improvements in how we collect, use, and share lidar data, and we argue that as lidar acquisitions mature we are well positioned to produce ethical, impactful, and reproducible research using the technique. Keywords: lidar; archaeology; ethics; accessibility; stakeholders; public education 1. Introduction data — and lidar data in particular — make them funda- Over the past two decades, remote sensing technologies mentally different from other kinds of data conventionally (RST) and the use of lidar-derived (here we use “lidar” as used by archaeologists, and raise a series of quite specific opposed to various other acronyms for “light detection ethical concerns. Since guidelines for ‘best practice’ can and ranging” (see Deering and Stoker 2014)) products have offer a useful framework for conducting ethical scientific become widespread on archaeological projects around research, we argue that archaeologists should, therefore, the world, and yet limited attention has been paid to the develop a series of best practices and ultimately a code ethical concerns of collecting and maintaining these data- of ethics for collecting, maintaining, and reproducing RST sets (Fernandez-Diaz et al. 2018). Scholars who work with datasets in our work. Big Data in fields such as geography, the digital humani- In recent years there has been growing concern about ties, and science and technology studies have reflected on the ways in which archaeologists use RST data, and a many of the issues involved (e.g., Markham, Tiidenberg, series of questions have been raised about the ethics of and Herman 2018; Pels et al. 2018; Richards and King lidar specifically (Begley 2016; Fernandez-Diaz et al. 2018). 2014), but archaeologists must more fully contribute to These issues frame our discussion here and inform other the conversation (for related scholarship on digital issues, papers in this Special Collection. For example, scientists see Bevan 2015; Huggett 2012; Kansa and Kansa 2018; routinely obtain permits from government officials before McCoy 2017; Richardson 2018). It is important to point collecting remotely sensed data — but when or how do we out that the degree of scale and detail, the comprehen- consult with local communities and stakeholders on the sive coverage, and the interdisciplinary importance of RST ground? How can RST datasets be integrated into collabo- rative, community-based archaeological and interdiscipli- nary research programs? After the data are collected, who * Utah State University, US has access to the datasets, and where are they housed? † University of British Columbia, CA How can we use legacy remote datasets to document ‡ École française d’Extrême-Orient, FR the rate of cultural heritage destruction and earth sys- Corresponding author: Anna Cohen ([email protected]) tems change? There are very compelling reasons to move Cohen et al: Ethics in Archaeological Lidar 77 towards open access models in our research, but what if for archaeological purposes: 1) future access to and dis- these are inconsistent with the desires or interests of cer- semination of data; 2) how to engage stakeholders; and tain communities and stakeholders? Given the diversity of 3) how to promote public education. We draw on examples the cultural and regulatory contexts in which we routinely from our own work to illustrate why these kinds of issues work, how can ethical principles be applied globally? Are should be recognized and considered before embarking on concerns about sharing location information and looting programs of archaeological lidar. Our introductory discus- the same cross-culturally, and to what extent can these sion aims to set the stage for the papers in this Special concerns be substantiated? Collection, all of which, to some degree or another, touch In this paper, we set out to explore these themes, and on the issues that we present here. Indeed, what we see we suggest a checklist that archaeologists may do well to is that common questions and concerns emerge from consider before acquiring remote sensing data, and lidar archaeological lidar research worldwide — from contribu- data specifically. We aim to move towards a code of ethics tors working in very different cultural and environmen- for archaeological remote sensing, and to encourage care- tal contexts in Europe, the Americas, Southeast Asia, and ful consideration of research ethics at every stage of the beyond — which underscores the need to develop guiding research process. We offer case studies from our work col- principles to ensure that our research is robust, reliable, lecting and analyzing airborne laser scanning (ALS) data ethical, and reproducible. in Latin America and Southeast Asia (Figure 1), drawing on diverse cultural and environmental contexts to make a 2. Ethics, Sovereignty, and Airspace case for lidar ethics. Our focus is on airborne lidar, but we As Smith and Burke (2003) have pointed out, all ethical anticipate that our discussion should be broadly relevant codes in archaeology were developed within a Eurocentric to other types of RST, including data derived from satellite disciplinary context (see also Lynott and Wylie 1995; platforms, UAVs, ground-penetrating radar, photogram- Wylie 2002: 229–234, 2003). Apart from the Society for metry, terrestrial laser scanning, and other kinds of geo- Professional Archaeologists (SOPA, now the U.S. Register spatial imagery and data. for Public Archaeologists) code, which was created in the First, we offer a brief overview of ethical codes and 1970s, most codes were developed in the 1990s. These guidelines in archaeological research, and how these developments built on earlier discussion of archaeological codes are a relatively recent and Eurocentric develop- ethics, catalyzed in particular by the passage of the United ment in the discipline. This survey of ethical frameworks Nations Act of 1985 and the indigenous and Native rights in archaeology will be useful for locating our discussion movements around the world in the 1960s–1980s (for within a broader disciplinary context. We then examine historical context, see Davis 1984; Lynott and Wylie 1995; the increasingly widespread use of archaeological lidar Watkins 2000: Ch. 2). In the U.S., the Native American and consider how we can learn from recent experiences Graves Protection and Repatriation Act (NAGPRA) in 1990 to improve future work. We highlight three factors that resulted in substantial debate among archaeologists, archaeologists should consider before collecting lidar data Native peoples, and other stakeholders (Atalay 2006, Figure 1: Map of countries for which there are wide-area public lidar datasets used for archaeology and countries with wide-area acquisitions by archaeologists in the peer-reviewed literature (https://angkorlidar.org/bibliogra- phy/). We define “wide-area” as >100 km2. 78 Cohen et al: Ethics in Archaeological Lidar 2012; Trope and Echo-Hawk 1992; Zimmerman 1992) are barely represented (see also Figure 1). This coincides while reburial concerns among Aboriginal Australians with Bevan’s (2015) point that one outcome of the cur- have long been an important part of early human archae- rent growth in digital archaeological information is that ology in Australia (Morell 1995; Smith and Jackson 2006). existing wealthy, computer-savvy parts of the world are Archaeological ethics codes emphasize some overlap- best positioned to generate and exploit digital datasets. ping but also distinctive concerns: the Archaeological Access to the tools and benefits of the geospatial and the Institute of America emphasizes