Detecting Landscape Disturbance at the Nasca Lines Using SAR Data Collected from Airborne and Satellite Platforms

Abstract

Abstract:We used synthetic aperture radar (SAR) data collected over Peru's Lines and Geoglyphs of Nasca and Palpa World Heritage Site to detect and measure landscape disturbance threatening world-renowned archaeological features and ecosystems. We employed algorithms to calculate correlations between pairs of SAR returns, collected at different times, and generate correlation images. Landscape disturbances even on the scale of pedestrian travel are discernible in correlation images generated from airborne, L-band SAR. Correlation images derived from C-band SAR data collected by the European Space Agency's Sentinel-1 satellites also provide detailed landscape change information. Because the two Sentinel-1 satellites together have a repeat pass interval that can be as short as six days, products derived from their data can not only provide information on the location and degree of ground disturbance, but also identify a time window of about one to three weeks during which disturbance must have occurred. For Sentinel-1, this does not depend on collecting data in fine-beam modes, which generally sacrifice the size of the area covered for a higher spatial resolution. We also report on pixel value stretching for a visual analysis of SAR data, quantitative assessment of landscape disturbance, and statistical testing for significant landscape change.

Earth Observation, Remote Sensing and Geoscientific Ground Investigations for Archaeological and Heritage Research

“…Agapiou et al [8] 3278 1904 5 Agapiou et al [3] 1708 970 8 Chyla [9] 1429 827 1 Comer et al [5] 1570 1102 3 Corso et al [12] 1753 1215 2 Danti et al [10] 1943 1740 7 Drap et al [13] 1571 1565 2 Gade et al [6] 1751 1210 4 Garcia-Garcia et al [14] 1282 995 1 Guidi et al [15] 1719 976 3 Kalayci et al [16] 1218 968 2 Křivánek [17] 1420 1174 2 Malinverni et al [18] 1445 1345 1 Parcak et al [11] 1486 1374 3 Poux et al [19] 2306 2249 7 Rayne et al [7] 1750 1500 5 Rutishauser et al [4] 1784 1345 2 Sonnemann et al [20] 1582 1046 2 Tapete [1] 1256 2313 3 Traviglia & Torsello [2] 1680 1311 9 Verhoeven [21] 1573 1399 6 Building upon the positive outcome achieved in 2017 and in order to continue this Special Series, in March 2018 I launched the call for papers for a second edition of the Special Issue with the title "Earth Observation, Remote Sensing and Geoscientific Ground Investigations for Archaeological and Heritage Research".…”

High Resolution Drone Surveying of the Pista Geoglyph in Palpa, Peru

“…Many other projects have used optical VHR satellites in the form of orthophoto or DSM (digital surface model [27,28], it can be created from at least two different image data sets based on image correlation technique) [29]. Other projects have focused on the use of radar recordings from satellites and creating of digital relief model (DRM) using InSAR technology (an interferometric analysis of SAR data) [30][31][32].…”

Remote Sensing and Geosciences for Archaeology

“…Instead, the novelty nowadays lies in the use of new imaging modes (mostly from new or current space missions) and higher spatial resolution and more accurate derived products, as well as the development of methodologies integrating multi-source SAR data. It is with regard to these aspects that the papers published in the Special Issue [11,16,17] offer interesting evidence of scientific research achievements.…”

“…Sentinel-1 data therefore can be valuable to feed into studies of landscape archaeology and wide-area monitoring activities. It is with this purpose that Comer et al [16] experimented with Sentinel-1 images to detect and measure landscape disturbance threatening the world-renowned archaeological features and ecosystems of the Lines and Geoglyphs of the Nasca and Palpa World Heritage Site in Peru. Multi-scale and multi-band analysis was also achieved thanks to targeted airborne surveys that were undertaken with the National Aeronautics and Space Administration (NASA)/Jet Propulsion Laboratory (JPL) Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) platform.…”

“…The papers published in the Special Issue cover a wide spectrum of techniques: satellite Synthetic Aperture Radar (SAR) imaging [11,16,17]; optical remote sensing from high to very-high resolution space-borne sensors [12,13,[18][19][20][21]; geophysics including magnetometer surveys, Ground Penetrating Radar (GPR), geoelectric resistivity measurements, multi frequency Electromagnetic Induction (EMI), piezoelectric/seismoelectric methods [9,22,23]; photogrammetry [24]; terrestrial laser scanning and three-dimensional (3D) point clouds [25,26]. Some of the papers also explore the benefits of combining different approaches, e.g., optical remote sensing, aerial imagery and geophysical prospection [27,28], 3D surveys, and reconstruction in GIS environment [29].…”