Figure 1
Map of the Mariana Islands and detailed map of Guåhan with sampled archaeological sites.
Figure 2
Top: Historic depiction of latte (Freycinet 1825). Bottom: Andrea Jalandoni providing scale for House of Taga Latte (left); Latte near Fena Lake exposed during a recent wildfire (right).
Table 1
Feature confidence definitions for the lidar-derived products.
| RATING | CONFIDENCE | DEFINITION |
|---|---|---|
| 0 | None | No feature is visible. |
| 1 | Low | A feature is visible, but the shape is not clearly defined or possibly an anomaly of lidar data. |
| 2 | Medium | A feature is visibly detected but incomplete or indeterminate whether natural or anthropogenic. |
| 3 | High | A feature is clearly visible and is verified either by expert knowledge or ground-truthing. |
Table 2
Summary table of archaeological sites and their evaluated visibility in the 2017 aerial imagery and the confidence level of identifying the site in the DTM, DSM, and mDSM derived from the 2020 airborne lidar. The resolution of the lidar-derived DEM is also shown. (nd = not determined).
| TIME PERIOD | ARCHAEOLOGICAL SITE | 2017 IMAGERY VISIBILITY | 2020 AIRBORNE LIDAR | |||
|---|---|---|---|---|---|---|
| DTM | DSM | mDSM | DEM RESOLUTION | |||
| CONFIDENCE LEVEL | ||||||
| Latte | Hagåtña Latte Stone Park | no | 0 | 0 | 3 | 0.25 m |
| Tumon Latte Memorial | partial | 0 | 2 | 3 | 0.25 m | |
| Abo Cove gigao | yes | 0 | 0 | nd | 1 m | |
| Northern coastal wells | no | 2/3 | 0 | nd | 1 m | |
| Sigua agricultural terraces | no | 2 | 1 | nd | 1 m | |
| Spanish | Asan road | no | 1 | 0 | nd | 1 m |
| Talaifak Bridge | yes | 1 | 0 | nd | 1 m | |
| Plaza de España | yes | 2 | 3 | nd | 1 m | |
| Fort Soledad | yes | 2 | 2 | nd | 1 m | |
| Modern | AAFB anti-aircraft gun positions | no | 2 | 0 | nd | 1 m |
| Orote bomb craters | no | 3 | 0 | nd | 1 m | |
| Harmon housing development | no | 3 | 0 | nd | 1 m | |
| Sasa Bay fuel tank | no | 3 | 0 | nd | 1 m | |
Figure 3
Two sample latte sites, the Hagåtña Latte Stone Park and the Tumon Latte memorial, as shown on imagery and various lidar filtering methods visualised as a hillshade: aerial imagery from 2017, digital terrain model, digital surface model (DSM), and a modified DSM with points over 3 m above ground excluded. The lidar-derived digital elevation models have a cell resolution of 0.25 m.
Figure 4
Archaeological features from the Latte Period showing the 2017 aerial imagery on the left and the associated lidar-derived digital terrain model and digital surface model on the right, visualised as hillshades. Sites include the Abo Cove gigao, Litekyan wells, and the Sigua agricultural terraces and walls.
Figure 5
Archaeological features from the Spanish Period showing the 2017 aerial imagery on the left and the associated lidar-derived digital terrain model and digital surface model on the right, visualised as hillshades. Sites include Asan road, Talaifak Bridge, Plaza de España, and Fort Soledad.
Figure 6
Archaeological features from the Modern Period showing the 2017 aerial imagery on the left and the associated lidar-derived digital terrain model and digital surface model on the right, visualised as hillshades. Sites include Anderson Air Force Base gun position berms, Orote bomb craters, Harmon housing development, and Sasa Bay fuel tank berms.