The invention provides an absolute time
delay calibration
system of inter-
satellite link antennas of navigational satellites. The calibration
system comprises a reference frequency source, an inter-
satellite link
transmitter, an inter-
satellite link
receiver, a time interval counter, a controlling and
processing computer, an attenuator, a vector network analyzer and at least three inter-satellitelink antennas to be calibrated. The inter-satellite link antennas to be calibrated are subjected to pair-wise
coupling mutually and are formed as a transceiving link together with the inter-satellitelink
transmitter, the inter-satellite link
receiver, the attenuator and the cables therebetween. The time interval
counter measures the
time difference between second signals generated by the inter-satellite link
transmitter and the inter-satellite link
receiver respectively. The controlling and
processing computer reads measurement valves of the inter-satellite link receiver and the time interval counter so as to obtain the absolute time
delay of each inter-satellite link antenna to be calibrated after
data processing. The calibration
system provided by the invention adopts test signals which accord with an inter-satellite link transmission
signal system; a practical inter-satellite
signal transmission time delay can be reflected in the test result, so that the calibration system is higher in
measurement precision.