Song Meter Surge Suppressor User Guide
Wildlife Acoustics, Inc.
page
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GPS Time-Synch for the SM4
Overview
The Song Meter SM4 recorder is available with a GPS time-synch option. This model is called the SM4TS.
The SM4TS ships with additional electronics hidden inside the SM4 housing, a weatherproof GPS connector on the side of the recorder,
and a cabled weatherproof GPS receiver. Crystal oscillators used in clocks and electronics, including the SM4 are not perfect. One
crystal might be faster or slower than another, and oscillations might speed up or slow down by different amounts as temperature
changes.
When the GPS receiver is connected to the SM4, the GPS receiver synchronizes the SM4 clock to the GPS time base for extremely
accurate time stamping on all your recordings to facilitate localization calculations of wildlife signals
The SM4TS GPS receiver can synchronize your recordings across multiple recorders to within one millisecond. The start times are
synchronized to start on the second as indicated in the filename, and the sample rate is fine-tuned over the duration of the recording to
keep the recordings synchronized typically to less than one millisecond error.
NOTE
: The GPS Time Synch Option provides synchronized recordings, but additional tools are needed to determine the time of arrival of a particular
signal to each microphone and calculating the position of the source.
Installation and Use
1.
The GPS Time-Synch option requires the external GPS receiver to be connected to the SM4TS during recording. The second
external microphone connector of the SM4 has been replaced by an external GPS receiver connector. This does not prevent
the second internal microphone from being used.
