Introduction:

PASSCAL station installations can vary according to the type of equipment being used, the physical environment, and also the legal responsibilities due the land owner or administrator.  For the latter, it is assumed that the full consent of the land owner/administrator for the station to be installed, operated for the required duration, and then final removal has been obtained.  It is further assumed that state laws regarding digging permits are also being followed. See also Guidelines for Station Installation.

Installing a PASSCAL seismic station involves the placement of a number of different, but coupled, sub-systems, including (but not limited to):

In July and August of 2009, seven scientists deployed several seismic sensors for a two-year multidisciplinary study of one of the world's most active volcanoes, the Sierra Negra Volcano of the Galápagos Islands. The project's official name is “Collaborative Research: An integrated seismic-geodetic study of active magmatic processes at Sierra Negra volcano, Galápagos Islands.”

August 20, 2008 Updated: December 15, 2008. Program refj31fix released

Stations Affected: RT130 connected to a 130-GPS/01 with SiRF ublox Trimble module installed (aka SiRF-type)

Description of Problem: Starting on July 31st 2008 (julian day 213 2008) the SiRF-type started to shift in time by a second.  Since the 31st July 2008 the mysterious time shifts (back and forth) continue. At present SiRF has no explanation for these time shifts.

Identifying SiRF GPS:

  Salient Features: 120s - 50 Hz flat velocity response Remote electronic mass locking, unlocking and centering. Installation & Troubleshooting Documents: Example of 3T/RT130 setup One-pager field sheet
Manufacturer's Documents: Guralp CMG-3T Manual Datasheet, Manual & Quick Start Guide