Abstract SQUID sensors are increasingly used in geophysical applications because of lower intrinsic noise and greater compactness compared to sensor systems using other technology. The lower intrinsic noise of the SQUID may be lost unless care is taken in analog and digital processing of the sensor outputs. Data analysis and further signal processing is application dependent, but again needs to be optimized to utilize the SQUID's advantages as a sensor. The portability of the SQUID magnetometer has encouraged its use with infield digital signal processing. New developments in dedicated digital signal processing integrated circuits are expected to be incorporated with SQUID sensors in vastly improved measurement systems.