Isles of Garrisons: remote sensing Ijangs in northern Philippines (sixteenth-century)

Abstract

The paper revisits the notion of openness or passive receptiveness of Island Southeast Asia to trading and raiding in light of historical geographic data on the northern Philippines that indicate the presence of garrison or ijang complexes that were equipped with prepositioned cannons or lantakas that operated in tandem with an early warning system facilitated by indigenous fast craft vessels. The paper utilizes primary and secondary sixteenth-century historical records with information about the potential location of these Ijangs with lantakas in some cases using incidental intelligence. Some examples are also provided wherein Ijangs in subsequent centuries when the archipelago became a colony started to be reconfigured as fortified Churches oriented towards defense from attacks originating not only from the sea but also from the mountain interiors. Remote Sensing was done using data from high resolution WorldView3 and WorldView2 satellites (DigitalGlobe Foundation) as well as ArcGIS Online World Imagery (Esri, DigitalGlobe, GeoEye, i-cubed, USDA FSA, USGS, AEX, Getmapping, Aerogrid, IGN, IGP, swisstopo, and the GIS User Community).