The AGSL's Aerial Photograph Finder web mapping application is a project that I completed in April 2018. The goal of the project was to make the library's digital aerial photography collection accessible to browse and search. The aerial photography is stored on a network drive within a catalog tree based on Wisconsin county and then by year and publisher. In the past a patron would fill out a data request form and describe the geographic extent and date range of aerial imagery that they were looking for. Library staff would locate the area of interest in ArcMap and either create an index shapefile for the entire folder to locate the requested image or they would load individual photographs from the folder until they found the one they were looking for. This was a very time consuming process that needed to be addressed.
Creating this web map application introduced me to ArcGIS Developer SDK that allowed me to use my HTML, CSS and JavaScript knowledge to produce an easy to use catalog of the AGSL's digital aerial photograph records that could not have been accomplished using the basic ArcOnline (AGOL) webapp builder. I was also introduced to Arc Server Manager and used administrative privelages to host the web app and shapefiles for online access. By hosting the application and layer files on the webserver, both can easily be updated by providing network access to the library staff.
This project had been in development for years and prior work to create a web application left me a geodatabase with a few shapefiles of photographs and the basic structure of the web app. The difficulty in prior attempts appeared to be connecting the shapefile layer with the web application and also creating an interface for querying. The ArcGIS developer SDK allowed for customized widgets that are not included with the AGOL appbuilder. Installing a customized search widget allows the shapefile to be queried spatially, as well as through text or a combination of the two.
To create the polygons for each digital photograph, a raster to index addon tool was used in ArcMap. The index tool has the ability to read through an entire folder and create polygons of the photographs geographic extent, which are stored in shapefiles along with metadata. However, some metadata such as the geographic projection was not included and it was necessary to use the define tool in ArcMap to properly project the polygons. The shapefiles exported into a file geodatabase with individual shapefiles for each county's year.
Please find the web map application and guide below.