A method comprising: receiving a first optical signal transmitted by a first moving platform , the first optical signal comprising a first plurality of pulses ; adjusting a command signal at a second moving platform such that the received first plurality of pulses overlap a second plurality of pulses generated at the second moving platform; transmitting a second optical signal comprising the second plurality of pulses from the second moving platform to the first moving platform, wherein each of the second plurality of pulses is transmitted from the second moving platform at the same time each of the first plurality of pulses is received at the second moving platform; and determining a first time offset between a first clock in the first moving platform and a second clock in the second moving platform based on the second plurality of pulses received at the first moving platform, wherein determining the first time offset comprises: determining a Doppler shift between the first and second moving platforms based on a first frequency at which the first plurality of pulses are transmitted from the first moving platform and a second frequency at which the second plurality of pulses are received at the first moving platform; and receiving, at the first moving platform, a value of the command signal used to overlap the first plurality of pulses and the second plurality of pulses at the second moving platform; and determining a frequency offset between the first and second clocks based on the Doppler shift and the value of the command signal. receiving a first optical signal transmitted by a first moving platform , the first optical signal comprising a first plurality of pulses ; adjusting a command signal at a second moving platform such that the received first plurality of pulses overlap a second plurality of pulses generated at the second moving platform; transmitting a second optical signal comprising the second plurality of pulses from the second moving platform to the first moving platform, wherein each of the second plurality of pulses is transmitted from the second moving platform at the same time each of the first plurality of pulses is received at the second moving platform; and determining a first time offset between a first clock in the first moving platform and a second clock in the second moving platform based on the second plurality of pulses received at the first moving platform, wherein determining the first time offset comprises: determining a Doppler shift between the first and second moving platforms based on a first frequency at which the first plurality of pulses are transmitted from the first moving platform and a second frequency at which the second plurality of pulses are received at the first moving platform; and receiving, at the first moving platform, a value of the command signal used to overlap the first plurality of pulses and the second plurality of pulses at the second moving platform; and determining a frequency offset between the first and second clocks based on the Doppler shift and the value of the command signal. determining a Doppler shift between the first and second moving platforms based on a first frequency at which the first plurality of pulses are transmitted from the first moving platform and a second frequency at which the second plurality of pulses are received at the first moving platform; and receiving, at the first moving platform, a value of the command signal used to overlap the first plurality of pulses and the second plurality of pulses at the second moving platform; and determining a frequency offset between the first and second clocks based on the Doppler shift and the value of the command signal. <EOS>