DOI: 10.5066/p13j32j4
title: Satellite Imagery Products from 2010, 2011, 2018 and Soil Data from 2021-22 on Jamestown Island, VA

description: The U.S. Geological Survey, in partnership with the National Park Service's Colonial National Historic Park (COLO), used commercially available satellite data and soil samples from around Jamestown Island to evaluate vegetative health and soil conditions on the island to further understand the extent and severity of conditions that threaten archaeological sites and vegetation. 50 sites were initially selected for sampling, however, only 48 of the sites were accessible in either June 2021 or March 2022. The soil samples were collected from 2 depths at 48 different sites around the island. The first sample was collected just below the land surface in the O horizon, and the second sample was collected from a minimum of 0.34 ft below the land surface in the A horizon. Two soil sampling efforts were conducted, one in June 2021 and a second in March 2022 to represent drier and wetter times of the year. Measurements of temperature in degrees Celsius, moisture content in percent volume, and soil conductivity in millisiemens per centimeter, were made using a Dynamax WET-2 sensor. Soil pH was also measured using the U.S. Environmental Protection Agency's 9045D method.

Satellite imagery, multispectral and panchromatic images, used in the project come from the GeoEYE, QuickBird 2, WorldView 2, and WorldView 3 satellites operated by the European Space Agency and Digital Globe  . USGS used panchromatic and multispectral images of Jamestown Island taken from 2010 – 2018 to create Normalized Difference Vegetative Index (NDVI) and difference of NDVI rasters to evaluate vegetative stress across Jamestown Island over time.   The images used were acquired using the USGS's Commercial Remote Sensing Space Policy (CRSSP) Imagery Derived Requirements (CIDR) tool. The search terms used for the CIDR request were for multispectral and panchromatic images of Jamestown Island, VA at a standard (2A) processing level with an image resolution of 1-4m, a max cloud cover of 20%, from 05/01/2008 - 07/28/2022. The search returned 12 images, or scenes, of which 4 were used for the associated publication. The collection dates, satellite platform and panchromatic and multispectral ground sample distances (GSD) respectively are as follows:

- 11/28/2010 at 16:24 from WorldView 2; GSD 1.509 ft and 5.906 ft
- 06/25/2011 at 15:56 by GeoEye; GSD 1.345ft and 5.413 ft
- 10/10/2011 by QuickBird 2; GSD 2.001 ft and 7.874 ft
- 2/12/2018 at 16:08 by WorldView 3; GSD 1.017 ft and 4.068 ft

The multispectral images were pan-sharpened to increase the resolution for visual light rasters of Jamestown Island using ESRI ArcGIS Pro's Pan-Sharpen tool utilizing the Graham-Schmidt method. Additionally, the 4 multispectral images were used to create normalized difference vegetative index  rasters using the ESRI ArcGIS Pro NDVI tool. For images with multiple near-infrared (NIR) bands, the first NIR band was used to create the NDVI rasters. A difference of NDVI raster was created using the Raster Calculator tool in ArcGIS Pro to show change in vegetative heath over time. The 11/28/2010 WorldView 2 and 12/12/2018 WorldView 3 NDVI rasters with water removed from the rasters were used to create the difference of NDVI raster. The GSD for the difference of NDVI raster is 5.906 ft. The original multispectral and panchromatic images could not be published in this data release as the rights for those images belong to European Space Agency or Digital Globe. As such only the derived products, the pan-sharpened image, NDVI rasters, and difference of NDVI raster have been published in this data release.