Popocatepetl is located approximately 44 miles southeast of Mexico City. This cone is the second highest peak in Mexico, and is counted among the most famous volcaoes in the world. The record of activity from this volcano includes large, pre-historical eruptions, spaced at intervals of roughly 1,000 years, with the last severe event occurring 1,200 years ago. This combined with the very dense concentration of human activity in the region (Mexico City, Puebla, etc.) indicates that Popocatepetl is and will remain a very dangerous volcanic hazard.
Volcanic risk assessment is performed by The Institute of Geophysics at the National Autonomous University of Mexico (UNAM), and immediately forwarded to the Centro Nacional de Prevencion de Desastres(National Center for Prevention of Disasters, also called CENAPRED). This information is used in addition to other lines of volcano monitoring to assess the volcanic risk to the adjacent communities.
The Institute of Geophysics uses geodetic techniques to assess volcanic risk. This involves using a branch of applied mathematics concerned with the size and shape of the earth, and the exact positions of points on its surface, along with a description of variations of its gravity field. The RPC-320 is used as part of a gloabal positioning system (GPS) to measure surface deformation. The Institute of Geophysics operates a system consisting of 10 stations positioned at the ediface, and 2 tilt-meter stations installed at the summit. Their strategy for monitoring volcanoes is based on the premise that crustal deformation due to magma chamber activity should be observed as a change in baseline length between stations. After the RPC-320 collects data, it then logs it, and transmits it via a RS-232 port to a radio modem. Raw GPS data is downloaded daily at UNAM via the radio modem , and within 24 hours after downloading, processed data is made available to CENAPRED. Data is also relayed over the internet to various research partners around the world.