A seismic data acquisition unit, comprising: a seismic sensor; a control processor to implement a control process for a local time base; a sample clock to provide a clock signal for analog-to-digital conversion of an output of the seismic sensor; at least one environmental sensor in communication with the control processor to provide data concerning a local environmental condition including a current inclination of the seismic data acquisition unit and a current operating temperature of the seismic data acquisition unit; an adjustable timing signal device to produce an adjustable timing signal for the sample clock, wherein said adjustable timing signal device is configured to be disciplined by the control processor utilizing data from the at least one environmental sensor, and wherein the control processor is configured to: determine the current inclination of the seismic data acquisition unit; determine the current operating temperature of the seismic data acquisition unit; determine, from a frequency compensation table, a stored inclination of the seismic data acquisition unit corresponding to the current operating temperature of the seismic data acquisition unit; identify a difference between the stored inclination corresponding to the current operating temperature and the current inclination; and aperiodically update a frequency of the adjustable timing signal device based on the difference between the current inclination and the stored inclination corresponding to the current operating temperature. a seismic sensor; a control processor to implement a control process for a local time base; a sample clock to provide a clock signal for analog-to-digital conversion of an output of the seismic sensor; at least one environmental sensor in communication with the control processor to provide data concerning a local environmental condition including a current inclination of the seismic data acquisition unit and a current operating temperature of the seismic data acquisition unit; an adjustable timing signal device to produce an adjustable timing signal for the sample clock, wherein said adjustable timing signal device is configured to be disciplined by the control processor utilizing data from the at least one environmental sensor, and wherein the control processor is configured to: determine the current inclination of the seismic data acquisition unit; determine the current operating temperature of the seismic data acquisition unit; determine, from a frequency compensation table, a stored inclination of the seismic data acquisition unit corresponding to the current operating temperature of the seismic data acquisition unit; identify a difference between the stored inclination corresponding to the current operating temperature and the current inclination; and aperiodically update a frequency of the adjustable timing signal device based on the difference between the current inclination and the stored inclination corresponding to the current operating temperature. determine the current inclination of the seismic data acquisition unit; determine the current operating temperature of the seismic data acquisition unit; determine, from a frequency compensation table, a stored inclination of the seismic data acquisition unit corresponding to the current operating temperature of the seismic data acquisition unit; identify a difference between the stored inclination corresponding to the current operating temperature and the current inclination; and aperiodically update a frequency of the adjustable timing signal device based on the difference between the current inclination and the stored inclination corresponding to the current operating temperature.