GARRICK TAYLOR BYRNE
GEOREFERENCING AND DIGITIZATION
Los Angeles City Oil Field, Los Angeles, California, U.S.
As part of a research project, I encountered a map in an online archive. While the scan quality was excellent, the map was not georeferenced. No vector file with feature locations and attributes existed. Thus, I needed to complete this GIS work myself.
DATABASE DESIGN
My GIS platform of choice is QGIS. QGIS has excellent support for digitizing tasks, but the attribute entry screens are not suited for large data entry jobs. I elected to store the attributes in a SQLite database, which can be joined to the vector point file through a foreign key field.
DELIVERABLES
All of the files mentioned here are hosted on my Github page.
DATABASE ENTITY RELATIONSHIP DIAGRAM
The ERD clarifies for users the interrelationships between the tables in the SQLite database.
SQLITE DATABASE
The attribute information for each point feature is stored in a SQLite database. Users can easily join the SQLite database to the vector shape file.
QGIS GEOPACKAGE
The QGIS geopackage file contains the vector point file and the two raster map scans. For QGIS users, the geopackage could be a more elegant solution than using the ESRI shapefiles and the GeoTIFF files.
GEOREFERENCED GEOTIFF FILES
There are two GeoTIFF files, as the original map displayed the field in two noncontiguous parts. Georeferencing information is encoded within each TIF file.
ESRI SHAPEFILE
As the ESRI shapefile has been the industry standard for many years, even many non-ESRI products support shapefiles.