Configuration of Facilities for Observing Space Debris and NEOs, and Observation Plan

Kamisaibara Spaceguard Center
This radar observation facility consists of the following subsystems;

Radar subsystem
The radar is based on an active phased array antenna which includes radiators and transmitter/receiver/phased-shifter module. The antenna is connected to a signal processor to obtain information from the received signal.

A 12-meter-diameter radar dome protects the radar subsystem from severe environmental conditions, such as heavy snow.

This radar employs S-band frequencies to minimize the effect of Rayleigh waves in order to observe very tiny objects, such as space debris of 2 cm to 3 cm in size, in the future.

Specification of Radar Subsystem
Frequency S-band
Antenna aperture 3m x 3m
Angle resolution Less than 2.8 deg. for both azimuth and elevation
Range resolution 300m
Maximum processing range Up to 1,000km
Mechanical rotating speed More than 6 deg./sec

Beam control subsystem
The radar simultaneously tracks 10 different targets within the area scanned by its antenna. It can shift each beam electrically with a beam control subsystem, sending the phasing signal to the phase shifters.

For space debris observation, the space debris search beam will be scanned at the azimuth before acquisition. The tracking beam will then be controlled by auto tracking equipment just after acquisition.

* This facility can determine the orbit of space debris with one-pass data with sufficient accuracy to acquire the same debris within one day if visible.
* This facility is able to detect a 1-meter-diameter object at a slant range of 600 Km.
* This facility can track more than 10 pieces of space debris simultaneously.

Observation Plan
The primary target of this facility is LEO debris. Observations will be performed for reentry prediction, collision warning between spacecraft and debris, and the analysis of space events, for example, the explosion of a satellite.
The observation plan is based on debris orbit calculation results calculated by a special perturbation method with estimating atmospheric density model error.