In November, 1998, seven magnetometers were installed in the first phase of the deployment (blue sites in Figure 1). The next six magnetometers in the second phase are expected to be installed in October, 1999 (red sites in Figure 1).

The locations of the seven observatories in the first phase are shown in Table 1. The seven magnetometers operate smoothly and return the first batch of geomagnetic field data since the deployment. These data are now being processed and analyzed at IGCSB (Institute of Geophysics, China Seismological Bureau) and UCLA.

To ensure accurate and stable baselines, both the electronics and sensors are kept in thermally controlled environments in the design of the magnetometer system. Moreover, extra measure has been taken to ensure the stability and precise direction of each sensor. The CSB designed and manufactured a cylinder sleeve, as shown in Figure 1, which holds the sensor assembly and can be adjusted in both vertical and horizontal directions freely and precisely. The integrated sensor assembly is placed on a stable pier in the recording room (Figure 2). This measure can increase the stability of the baseline values. We are now testing the stability of baseline values in comparison with the absolute measurements of the geomagnetic field at Beijing (BJI) station (Figure 3).