In the operation of spaceborne optical sensor, it is necessary to increase time resolution due to cloud coverage. As for spaceborne radio sensor, it is necessary to observe different time due to changeable targets. In these cases, more constellations and higher performance will be needed in the future. Active radio sensor should have sufficient bandwidth and should protect other services. On the other hand, passive radio sensor should be protected from the interference of other services. Overall allocation and interference issues for active and passive radio sensors and their constellation are studied for the first time.

Present and future of allocation and protection of earth observation using constellation

A miniature microwave discharge plasma thruster for micro satellites is under development, with the target power consumption, thrust and specific impulse of 10 W, 1 mN and 1000 sec, respectively. Thrust was estimated from the measured ion beam current and ion energy distribution function using an ion collector and a retarding potential analyzer. Several parameters, including antenna configuration, length of the discharge chamber and configuration, were optimized for the improvement of the thrust performance. The overall thrust was estimated to be 82 μN at the incident microwave power of 10 W and the mass flow rate of 82 g/sec.

Development of a Miniature Microwave Discharge Thruster

There are various natural and man-made disasters and abnormal weather in the world. In order to monitor such disasters and weather, it is necessary to observe the earth frequently by using spaceborne, airborne and ground based observation equipments. Constellation of small satellites with optical sensor or radio sensor is very useful to conduct afore-mentioned observation. In 2014, more than 10 microsatellites for remote sensing with the same and different orbital altitudes will make constellation and these constellation will contribute to monitoring earth environment. This is the largest number of microsatellites launched in the same year in the history of microsatellites. In this paper, overview of Hodoyoshi microsatellites and future microsatellites using technology of system and components of Hodoyoshi technology is presented.

Overview of Hodoyoshi microsatellites for remote sensing and its future prospect

The 6–7GHz band spaceborne microwave radiometer is very important because ocean surface temperature can be observed through cloud with highest sensitivity. Ocean surface temperature is very important in the study of global warming and others. However, 6–7GHz band is not protected in the Radio Regulations (R.R) of ITU-R. In this paper, various interferences to a spaceborne microwave radiometer imagery are classified and introduced. Some analysis is conducted for the first time in the world in the case of surface scattering of down link from mobile satellites to gateways.

Protection of 6–7GHZ band spaceborne microwave radiometer from interferences to derive sea surface temperature and others

In SAR-580 experiment using L/C/X band SAR mounted on Convair 580 was conducted for the first time in Japan. Based upon these results, L band HH was selected for SAR mounted on JERS-1. Later, PALSAR (full polarimetry) mounted on ALOS was developed and launched by H-IIA rocket. In FY 2013, PALSAR-2 mounted on ALOS-2 will be launched by H-IIA rocket. In this paper, present and future of spectral and technical issues of airborne and spaceborne L band SAR including small L band SAR to be resolved are presented.

http://ieeexplore.ieee.org/iel7/6690576/6704984/06705059.pdf

Maeda Korehiro

Papers

Present and Future of Small Observation Satellites

Utilities of Spaceborne Microwave Radiometer and its Protection -- Sharing Studies between AMSR and point-to-point fixed service stations

Present and Future of Small Satellites -- Observation and communication missions

Sharing studies for spaceborne L band SAR to contribute to disaster monitoring

Present and future of near earth satellite mission -- Application to observation and communication system of small satellites