CORONA Satellite Imagery Research Articles

Archaeological cognition of the Eastern mausoleum of Qin state using integrated space-ground observation tools

The Eastern Mausoleum of Qin State is a significant component of the Qin Dynasty's royal tombs, reflecting the social development level during the Warring States period (475 BC ~ 221 BC) in China. At the onset of our investigation, we mapped the site's boundaries utilizing Corona satellite imagery and employed the Normalized Difference Vegetation Index (NDVI) and Normalized Difference Moisture Index (NDMI) to identify archaeological features. Additionally, this study is the first to propose the use of thermal infrared band data from the SDGSAT-1 satellite to explore thermal archaeological traces, demonstrating their viability for archaeological site analysis. Subsequently, electromagnetic (EM) prospection was utilized to validate the presence of an ancient burial chamber passage. Landscape monitoring and analysis of the No.1 Mausoleum were performed using Corona and Google Earth images, revealing the accuracy of the Geomancy Theory of Chinese mausoleums through dynamic remote sensing of surface changes. Furthermore, our employment of space-to-ground observational modalities and resultant Digital Elevation Models (DEM) have been used to provided new insights into the application of Remote Sensing (RS) and Geomancy in archaeology, thereby emphasizing the pivotal role of site selection in heritage preservation. This research underscores the promise of synergistic space-ground observations in both exploiting the archaeological riches of cultural heritage sites and ensuring the enduring conservation of these irreplaceable patrimonial assets.

Morphological adjustments of the Yamuna River in the Himalayan foothills in response to natural and anthropogenic stresses

AbstractRivers can adjust to natural and anthropogenic stresses through changes in flow regime and sediment dynamics. Flow regulation due to dam construction can modify sediment transport processes, causing morphological adjustments and changes in conveyance capacity. In this study, we explored morphological adjustments along a 46 km segment of the Yamuna River in the Himalayan foothills from Dakpathar Barrage to Hathni Kund Barrage using a combination of remote sensing approaches. The cloud computing platform Google Earth Engine (GEE) was used to analyse multi‐temporal collections of Landsat satellite imagery acquired between 1989 and 2021. Active river channels (including water and exposed sediment) were classified using an MNDWI and NDVI thresholding approach from annually resolved temporal composite images. Declassified CORONA satellite imagery (acquired in 1965, 1973 and 1976) was manually digitized to provide longer‐term insights into channel change. Morphological adjustments were assessed using the RivMAP toolbox, providing quantitative information on the rates of bank erosion and accretion, bank line shifts and changes in active channel width. Results showed a substantial narrowing of the active channel after 2013, which coincided with the construction of the Lakhwar‐Vyasi Dam. We calculated a 67% reduction in mean active channel width, narrowing from ~800 m in 1989 to ~250 m in 2021. During the same period, evidence of sand mining in the active channel indicates a substantial increase in mining activities after 2015. The concept of stasis was explored under different flow regulation scenarios to suggest that the river has undergone a state of inactivity, where the river is doing nothing for much longer durations. We suggest that the combined effects of flow regulation and increased mining activities during the same period have altered river morphology, and further stresses due to a combination of human activities can be damaging for the river regime. This study sheds light on the potential implications of multiple stresses acting on the Yamuna River at the same time, which can inform future sustainable river management activities.

Assessing effectiveness of nature-based solution with big earth data: 60 years mangrove plantation program in Bangladesh coast

BackgroundIn the climate change context, nature-based solution (NBS) is considered one of the effective tools to increase the resilience of socio-ecological system. The concept coincides with the government’s attempts of afforestation and reforestation programs that have been going on for 60 years in Bangladesh. This study, therefore, envisaged understanding how NBS (mangrove afforestation and reforestation) works to promote climate change resilience through the synthetization of remote sensing-based big earth data, statistical tools, and models. The study took the entire coast of Bangladesh except for Sundarbans Reserve Forest and rolled back to 1962 to work on 60 years’ time series data. Declassified CORONA satellite imagery along with Landsat satellite imagery was used, which is the first-ever attempt in the remote sensing-based ecosystem work in Bangladesh.ResultsThe study's main innovation is to spatially establish the effectiveness of the NBS. The study critically assessed and estimated stable lands and their socio-economic benefits as part of the effectiveness of the NBS. As part of the NBS-derived benefits in the context of climate change, it estimated the sequestrated carbon in mangrove forests. A significant positive relationship was observed between the increase of mangroves and stable lands. Near about 448,011 ha of agricultural land was stabilized due to the NBS intervention whose economic value is 18,837 million USD. In addition, 29,755.71 kt of carbon have been sequestrated due to NBS program.ConclusionsThe concept of NBS is still in the development stage and very little or no work has been done so far in measuring and labeling the effectiveness of the NBS. Therefore, our study can innovatively contribute to the scientific community to show the effectiveness of the NBS in three domains (social, economic and ecological) in the changing climatic scenario.

The Substantial Increase of Forest Cover in Central Poland Following Extensive Land Abandonment: Szydłowiec County Case Study

Nowadays, Poland is one of the European countries most affected by agricultural land abandonment (ALA). Though considered to be a negative phenomenon, ALA opens up several options for planning future land uses critical for biodiversity conservation or future carbon sequestration. So far, many studies of ALA have been done in the mountainous areas in Poland, but less is known about the magnitude of ALA in other regions. In this paper we use the declassified CORONA satellite imagery (1969) to backdate the information on land cover and land abandonment from topographic maps from 1970s for the region located in central Poland and currently affected by widespread ALA. The information from archival materials is compared with current High-Resolution Layers and airborne laser scanning products, indicating that a forest cover increase of 23% was observed. The output of vegetation height analysis confirmed significant land use transformation from non-forest and ALA into forest area. Additionally, analysis of forest pattern change revealed that although forest core areas have increased since 1970, its share in total forest cover decreased due to newly established small forest patches. Our research shows the importance of archival remote sensing materials and indicates their role in understanding ALA-related forest cover change in Poland over the last 50 years.

Declassified intelligence satellite imagery as a tool to reconstruct past landforms and surface processes: The submerged riverscape of the Tigris River below the Mosul Dam Lake, Iraq

AbstractLocated along the Tigris River in the Kurdistan Region of Iraq, the Mosul Dam Reservoir is the second biggest dam of the Near East and represents an important water storage for local human activities. The dam was built between 1981 and 1988 north of the village of Eski Mosul, submerging the course of the Tigris River for c. 100 km. The analysis of historical images derived from declassified Corona satellite imagery acquired between December 1967 and August 1968 reveals the pristine pattern of the Tigris River, including the seasonal changes of its riverbed, shifting across the hydrological year from meandering to anastomosing patterns. Geomorphological mapping based on Corona images allowed us to estimate the seasonal modification of fluvial elements such as the floodplain and point, middle and longitudinal bars. The comparison with Landsat data collected since the 1990s showed the first phases of the basin filling and the control on the present‐day aspect of the lake inherited from the setting of the Tigris channel belt and, more in general, the litho‐structural control over the evolution of the local hydrographic network; we also document the influence of the original Tigris River course on its recent insertion into the lake. Our work allowed reconstruction of the ancient fluvial landscape below the Mosul Dam Lake and the evolution of its riverscape controlled by litho‐structural factors and seasonal variations of the river discharge. Finally, this contribution highlights the relevance of declassified intelligence satellite imagery in interpreting natural geomorphic processes and landforms, today altered by human agency.

Succeeding CORONA: declassified HEXAGON intelligence imagery for archaeological and historical research

Over the past 25 years, CORONA satellite imagery has become an integral part of archaeological research, especially for arid, sparsely vegetated regions such as the Middle East. Since 2020, a new archive of satellite imagery gathered by the US spy satellite programme that succeeded CORONA—HEXAGON—has become widely available for download via the United States Geological Survey. This photographic archive has enormous potential for archaeological research. Here, the authors seek to lower the barriers to accessing and using this imagery by detailing the background, technical specifications and history of the HEXAGON archive. Four case studies illustrate the benefits and limitations of HEXAGON imagery for archaeological and historical research in the Middle East and beyond.

The Khandaq Shapur: Defense, Irrigation, Boundary, Frontier

Khandaq Shapur has been named one of the great barriers of the ancient world, but very little is known about the monumental-scale linear feature. This interdisciplinary paper brings together archaeologists and historians to present (1) an updated history of the Khandaq Shapur drawing upon a wider range of sources, including Arabic scholarly sources, and (2) a modern map of the Khandaq Shapur produced from a ground truthed remote sensing using historic Corona satellite imagery from the 1960s and imagery available in Google Earth. This new map of the Khandaq Shapur’s ground truthed location is compared to the known locations of Sasanian sites from previous archaeological surveys to contextualise the Khandaq Shapur within the wider archaeological landscape. Together, the landscape archaeology and historical evidence provide a comprehensive picture of this unique feature: shedding light not only on its precise location, but also its nature (what was it?) and how it was used over time.

Effect of Land Use Change on Gully Erosion Density in the Black Soil Region of Northeast China From 1965 to 2015: A Case Study of the Kedong County

Kedong County is typical of the black soil region of northeast China in being highly susceptible to accelerated soil erosion by gullying. Using data sourced from Corona satellite imagery for 1965, SPOT5 for 2005 and GF-1 for 2015, the spatial distribution of gullies in the research area was mapped. Land use data for 1965, 2005, and 2015 were obtained from the topographic map of 1954, and from Landsat images for 2005 and 2015. Over the last 50 years, the extent of gully erosion in the study area has increased markedly, most notably on cultivated land, while gully density rose from 2,756.16 m2/km2 to 14,294.19 m2/km2. Cultivating land on slopes, especially on slopes greater than ∼4°, may rapidly aggravate gully erosion. The greatest increases in gully density occurred in situations when cultivated land and other/degraded land were transformed, which gully erosion density increased by 49,526.69 m2/km2. Other/degraded land is the most vulnerable land in the study area, with the highest gully erosion density. In these cases, gully density initially increases and, although the “Grain for Green” project has been implemented, gully erosion density has not always declined in the recent past.

Information Extraction and Population Estimates of Settlements from Historic Corona Satellite Imagery in the 1960s.

The Corona satellite program was a historic reconnaissance mission which provided high spatial resolution panchromatic images during the Cold War era. Nevertheless, and despite the historic uniqueness and importance of the dataset, efforts to extract tangible information from this dataset have primarily focused on visual interpretation. More sophisticated approaches have been either hampered or unrealized, often justified by the primitive quality of this early satellite product. In the current study we attempt to showcase the usability of Corona imagery outside the context of visual interpretation. Using a 1968 Corona image acquired over the city municipality of Plovdiv, Bulgaria, we reconstruct a panchromatic 1.8 m spatial resolution georegistered image with a relative displacement Root Mean Square Error (RMSE) of 6.616 (for x dimension) and 1.886 (for y dimension) and employ segmentation and texture analysis to discern agricultural parcels and settlements’ footprints. Population statistics of this past era are retrieved from national census and related to settlements’ footprints. An exponential relationship between the two variables was identified by applying a semi-log regression. The high adjusted R2 value found (76.54%) indicates that Corona images offer a unique opportunity for population data analysis of the past. Overall, we showcase that the Corona images’ usability extends beyond the visual interpretation, and features of interest extracted through image analysis can be subsequently used for further geographical and historical research.

Global-Scale Archaeological Prospection using CORONA Satellite Imagery: Automated, Crowd-Sourced, and Expert-led Approaches

ABSTRACTDeclassified CORONA satellite imagery, collected from 1960–1972 as part of the world’s first intelligence satellite program, provides nearly global, high-resolution, stereo imagery that predates many of the land-use changes seen in recent decades, and thus has proven to be an immensely valuable resource for archaeological research. While challenges involved in spatially correcting these unusual panoramic film images has long served as a stumbling block to researchers, an online tool called “Sunspot” now offers a straightforward process for efficient and accurate orthorectification of CORONA, helping to unlock the potential of this historical imagery for global-scale archaeological prospection. With these new opportunities come significant new challenges in how best to search through large imagery datasets like that offered by CORONA. In contrast to currently popular trends in archaeological remote sensing that seek to employ either automated, machine learning-based approaches, or alternatively, crowd-sourced approaches to assist in the identification of ancient sites and features, this paper argues for systematic, intensive, and expert-led “brute force” methods. Results from a project that has sought to map all sites and related features across a large study in the northern Fertile Crescent illustrate how an expert-led analysis may be the best means of generating nuanced, contextual understandings of complex archaeological landscapes.

Deep Learning in Archaeological Remote Sensing: Automated Qanat Detection in the Kurdistan Region of Iraq

In this paper, we report the results of our work on automated detection of qanat shafts on the Cold War-era CORONA Satellite Imagery. The increasing quantity of air and space-borne imagery available to archaeologists and the advances in computational science have created an emerging interest in automated archaeological detection. Traditional pattern recognition methods proved to have limited applicability for archaeological prospection, for a variety of reasons, including a high rate of false positives. Since 2012, however, a breakthrough has been made in the field of image recognition through deep learning. We have tested the application of deep convolutional neural networks (CNNs) for automated remote sensing detection of archaeological features. Our case study is the qanat systems of the Erbil Plain in the Kurdistan Region of Iraq. The signature of the underground qanat systems on the remote sensing data are the semi-circular openings of their vertical shafts. We choose to focus on qanat shafts because they are promising targets for pattern recognition and because the richness and the extent of the qanat landscapes cannot be properly captured across vast territories without automated techniques. Our project is the first effort to use automated techniques on historic satellite imagery that takes advantage of neither the spectral imagery resolution nor very high (sub-meter) spatial resolution.

Mass Loss From Calving in Himalayan Proglacial Lakes

The formation and expansion of Himalayan glacial lakes has implications for glacier dynamics, mass balance and glacial lake outburst floods (GLOFs). Subaerial and subaqueous calving is an important component of glacier mass loss but they have been difficult to track due to spatiotemporal resolution limitations in remote sensing data and few field observations. In this study, we used near-daily 3 m resolution PlanetScope imagery in conjunction with an uncrewed aerial vehicle (UAV) survey to quantify calving events and derive an empirical area–volume relationship to estimate calved glacier volume from planimetric iceberg areas. A calving event at Thulagi Glacier in 2017 was observed by satellite from before and during the event to nearly complete melting of the icebergs, and was observed in situ midway through the melting period, thus giving insights into the melting processes. In situ measurements of Thulagi Lake’s surface and water column indicate that daytime sunlight absorption heats mainly just the top metre of water, but this heat is efficiently mixed downwards through the top tens of metres due to forced convection by wind-blown icebergs; this heat then is retained by the lake and is available to melt the icebergs. Using satellite data, we assess seasonal glacier velocities, lake thermal regime and glacier surface elevation change for Thulagi, Lower Barun and Lhotse Shar glaciers and their associated lakes. The data reveal widely varying trends, likely signifying divergent future evolution. Glacier velocities derived from 1960/70s declassified Corona satellite imagery revealed evidence of glacier deceleration for Thulagi and Lhotse Shar glaciers, but acceleration at Lower Barun Glacier following lake development. We used published modelled ice thickness data to show that upon reaching their maximum extents, Imja, Lower Barun and Thulagi lakes will contain, respectively, about 90 × 106 , 62 × 106 and 5 × 106 m3 of additional water compared to their 2018 volumes. Understanding lake–glacier interactions is essential to predict future glacier mass loss, lake formation and associated hazards.

Monitoring landscape changes and spatial urban expansion using multi-source remote sensing imagery in Al-Aziziyah Valley, Makkah, KSA

The CORONA satellite imagery acquired in 1967 enabled retrieving the initial geomorphic landscape of Al-Aziziyah valley which comprises mountain ridges, extended mountain ridges, isolated hills, and alluvial plains. The CORONA image implied a minimal landuse features in Al-Aziziyah valley. On the other hand, the QuickBird image acquired in 2005 demonstrated extensive urban expansion on the expense of the initial morphologic features. The various urban features have occupied ∼62% of Al-Aziziyah valley. The residential areas and road networks are the major landuse features occupying ∼39% of the entire study area. The governmental, hotels, educational, and the commercial features along with the public service locations represented ∼21% of the study area. The QuickBird image acquired in 2005 enabled mapping the bare lands located among the various landuse features along with the mountainous areas that are under preparation for future urban expansions. Both the bare lands and the planned mountainous areas represented ∼18% of the study area. All urban expansions have occurred either over, through, or instead the various initial morphologic features resulting in reshaping the physiographic characteristics of the landscape of the study area.

Topographic controls on the surging behaviour of Sabche Glacier, Nepal (1967 to 2017)

Using a combination of Landsat, Pléiades and CORONA satellite imagery from 1967 to 2017, we map changes in the terminus position, ice surface velocity and surface elevation of Sabche Glacier, and report the first observations of surging behaviour in central Nepal. Our observations show that Sabche Glacier surged four times over the last 50 years. The three most recent surges occurred at 10 to 11-year cycles, which is one of the shortest surge cycles ever recorded. Detailed analysis of the most recent surge (2012 onwards), indicates that the glacier advanced 2.2 km and experienced maximum velocities of 1.6 ± 0.10 m day−1. During this surge, there was a surface elevation gain at the terminus of up to 90 ± 6.19 m a−1, with a corresponding surface lowering of between 10 ± 6.19 and 60 ± 6.19 m a−1, 3 km up-glacier of the terminus. This transfer of mass amounted to a volume of ~2.7 × 107 ± 0.1 × 107 m3a−1. Sabche Glacier is the first surge-type glacier to be observed in the central Himalayas, but this is consistent with a previous global analysis which indicates that surge-type glaciers should exist in the region. We hypothesise that the surge is at least partially controlled by subglacial topography, whereby a major subglacial overdeepening and constriction 3 km up-glacier of the terminus provides resistance to glacier flow from the accumulation area to the ablation area. This overdeepening appears to store mass until a threshold is crossed, after which the glacier flows out of the subglacial depression and rapidly surges over a bedrock lip and down the valley. Thus, whilst the surges are likely to be facilitated by subglacial processes (e.g. changes in subglacial hydrology and/or basal thermal regime), the topographic setting of the glacier appears to be modulating both the timing and duration of each surge.

Archaeological fieldwork in Berenike in 2014 and 2015: from Hellenistic rock-cut installations to abandoned temple ruins

The report brings a comprehensive summary of archaeological fieldwork and survey carried out in Berenike on the Red Sea coast of Egypt and in the Eastern Desert hinterland over the course of two seasons in 2014 and 2015. The completed magnetic map of the site is discussed in some detail, assessing the potential for future excavations. The report covers the most important discoveries of the two seasons, which include fragments of Middle Kingdom Pharaonic stelae, possibly pushing back the foundation of the harbor, archaeological evidence of a rock-cut watercollection system forming part of the Hellenistic-age fortifications and two inscribed stone bases, one of which records a secretary of an aromatics warehouse at Berenike, discovered undisturbed in the courtyard of the Great Temple of Berenike (also called the Serapis Temple). A previously unknown religious(?) complex was discovered on the western outskirts of the site thanks to work with Corona satellite imagery. In turn, analysis of the magnetic mapping of the city revealed an administrative(?) complex in the northern part of the town; the later, 5th and 6th century layers were examined inside a chamber with niche forming part of this complex. Work also continued in the early Roman harbor, uncovering among others a complete timber ship frame, and a collection of garnets in subsidiary buildings in the late Roman temenos located in the entrance to the southwestern bay.

Urban and Rural Landslide Hazard and Exposure Mapping Using Landsat and Corona Satellite Imagery for Tehran and the Alborz Mountains, Iran

Tehran, Karaj, Quazvin and nearby rural areas in the Alborz Mountains, Iran are prone to earthquake and landslide hazards. Risks for settlement areas, transport infrastructure and pastoralist areas exist due to a combination of natural as well as man-made factors. This study analyses data derived from satellite and airborne sensors, specifically, Landsat and declassified Corona data to identify landslide occurrence and urban sprawl. In a Geographic Information System, other data such as geology, topography, road network and river flows were integrated from various sources. A digital elevation model (DEM) was computed based on contour lines that were extracted from topographic maps. The DEM allows for mapping topographic factors such as slope angle and aspect. Finally, change detection analysis has documented urban sprawl in massive dimensions since the 1970s. A multi-criteria landslide hazard and exposure zonation map was developed for a small rural area where several settlements and segments of roads were affected by landslides. The estimated risk areas were then overlaid with real landslide occurrences. The match of hypothetical and real event occurrence areas demonstrated the feasibility of this approach. The main contribution of this paper is to inform about recent landslide risks in Iran and how certain factors can be derived from spatial information.

CORONA画像の実体視判読に基づく1957年 Gobi-Altay地震の地表地震断層の認定

CORONA画像の実体視判読に基づく1957年 Gobi-Altay地震の地表地震断層の認定

Regional-Scale Archaeological Remote Sensing in the Age of Big Data

AbstractWith the ever expanding quantity of high-resolution aerial and satellite imagery available to archaeologists, numerous researchers have sought to address this “big data” challenge by developing automated methods to aid in the discovery and mapping of archaeological sites and features. This paper reviews several notable efforts to create automated discovery tools, including both spectral and object-based approaches, and highlights the difficulties these projects have encountered. Arguing instead for the critically important role of a human analyst in archaeological discovery, I illustrate interim results of an ongoing project that utilizes CORONA satellite imagery to document previously unknown sites in a 300,000 km2study area in the northern Fertile Crescent. The project is based on what I term “brute force” methods, relying on systematic exploration of imagery by trained analysts, and has now successfully created a database of more than 14,000 sites, some 10,000 of which are previously undocumented. Results of the project highlight the need for human intervention to make any archaeological discovery meaningful, suggesting that imagery analysis, like any act of archaeological investigation, requires an engaged, thoughtful and creative scholar.

Radial route systems and agro-pastoral strategies in the Fertile Crescent: New discoveries from western Syria and southwestern Iran

Radial systems of spoke-like pathways, often termed “hollow ways,” are frequently found surrounding mounded tell sites in northern Mesopotamia and have been explained as the product of a particular set of land use practices involving dry-farming agriculture and intensive ovicaprid pastoralism. Yet while similar subsistence strategies were very common across the Near East throughout much of the Holocene, classic hollow ways have only been previously documented in a small region and articulate almost exclusively with sites of the third millennium BC. This paper presents newly discovered hollow ways in western Syria and southwestern Iran, made possible through analysis of an online database of declassified, Cold War-era CORONA satellite imagery. The association of these previously undocumented ancient roads with archaeological sites dating to the Iron Age, Roman/late Roman and early medieval periods, suggests that the land use practices which produced radial route systems may have been quite widespread. Taking into account the wide geographic and temporal distribution of hollow ways, analysis explores various aspects of the agro-pastoral systems that disparate communities may have shared. Results confirm some aspects existing models of hollow way formation, while offering some refinements in terms of the roles that settlement organization, agricultural land use and pastoral strategies play.

Swords into Ploughshares: Archaeological Applications of CORONA Satellite Imagery in the Near East

Swords into Ploughshares: Archaeological Applications of CORONA Satellite Imagery in the Near East