Abstract:
A high frequency interferometric radar system was used to monitor the movement of a historic landslide in the mountains of southwest Colorado over a 5 day period. The system has a movement resolution of 0.1 mm with a field of view of 70 degrees and the capability of resolving movements out to 4 kilometers. At that distance the pixel measured is 0.75 m deep by 17 m wide. The system was mounted on top of a mountain to provide a direct view of the landslide area. The system was further used as a ground based interferometric radar system for a two-month period to monitor potential rock-fall of an at risk slope in Glenwood Canyon, Colorado. The slope of concern is directly above Interstate 70 and over the past two decades has released damaging rock-fall on multiple occasions. Displacement measurements were made from the rim of the south side of the canyon, over 300 meters above the highway and 600 meters across the canyon from the slope of interest (north wall). The compact interferometric radar system was installed in the remote canyon location (within National Forest) via helicopter access with minimal impact to the environment. The interferometric radar system utilizes the stepped-frequency-continuous-wave (SFCW) technique along with a synthetic aperture radar (SAR). The analyzed data were overlain on a digital terrain model (DTM) to illustrate the locations of the measured pixels. Measurements were performed at approximately 5 ÂÃ'½ minute intervals. Data was automatically transferred via a cellular connection to a server where the data was autonomously processed to check for alarm level movement.