Session
Weekend Session VIII: Advanced Technologies - Research & Academia 2
Location
Utah State University, Logan, UT
Abstract
We propose a method of omnidirectional radio interferometry in space using a three-dimensional tensegrity array antenna deployed from a small satellite. Tensegrity means a stable and self-equilibrating structure based on the balance of compressive and tensile forces between compression and tension members. The advantages of the tensegrity structure are that it is lightweight and can be stored compactly, reducing launch costs and enabling deployment in orbit. This structure is therefore attracting interest for various applications such as space antennas, starshades, and planetary exploration. In this study, we investigated a tensegrity array antenna that can be deployed from small satellites as a platform for a space-based radio interferometer. This is an attempt to advance the proposed method of omnidirectional radio interferometry to enable us to configure sensor pairs with multiple baseline lengths and arbitrarily change the baseline vectors with respect to the observation target by rotating the satellite. With a wide field of view, the tensegrity array antenna employing this method can serve a variety of applications, including science and space situational awareness.
The tensegrity array antenna deploys bars and thin films as compression and tension members of the tensegrity structure to form a tensegrity icosahedron with an outer shape more than twice as large as that of a small satellite in storage. The bars are used as pole antennas and the thin films as patch antennas to form a three-dimensional array antenna with thirteen axes of rotational symmetry. We propose the method to estimate the omnidirectional distribution of the scalar sources by measuring the interference between the antenna pairs while rotating the tensegrity array antenna around the rotational symmetry axis.
We present the configuration of the tensegrity array antenna as well as its deployment. We also propose an estimation method for the omnidirectional distribution of the scalar sources by rotational interferometry using the spherical harmonic expansion. We report the verification results of this estimation method using the similarity rule between electromagnetics and acoustics. For the verification, we constructed a six-channel array microphone and measured uncorrelated one-third octave bandpass noise (center frequencies of 1 k and 2 kHz, corresponding to 0.9 G and 1.8 GHz in radio-frequency conversion) emitted from multiple directions in an anechoic chamber by rotating the array microphone. The results indicate the ability to separate sources arriving simultaneously from multiple directions at 10 dB signal-to-noise ratio. This was achieved with the theoretical resolution of the interferometer. Finally, we discuss the development challenges and future works.
Omnidirectional Radio Interferometry Using Deployable Tensegrity Array Antenna Satellite
Utah State University, Logan, UT
We propose a method of omnidirectional radio interferometry in space using a three-dimensional tensegrity array antenna deployed from a small satellite. Tensegrity means a stable and self-equilibrating structure based on the balance of compressive and tensile forces between compression and tension members. The advantages of the tensegrity structure are that it is lightweight and can be stored compactly, reducing launch costs and enabling deployment in orbit. This structure is therefore attracting interest for various applications such as space antennas, starshades, and planetary exploration. In this study, we investigated a tensegrity array antenna that can be deployed from small satellites as a platform for a space-based radio interferometer. This is an attempt to advance the proposed method of omnidirectional radio interferometry to enable us to configure sensor pairs with multiple baseline lengths and arbitrarily change the baseline vectors with respect to the observation target by rotating the satellite. With a wide field of view, the tensegrity array antenna employing this method can serve a variety of applications, including science and space situational awareness.
The tensegrity array antenna deploys bars and thin films as compression and tension members of the tensegrity structure to form a tensegrity icosahedron with an outer shape more than twice as large as that of a small satellite in storage. The bars are used as pole antennas and the thin films as patch antennas to form a three-dimensional array antenna with thirteen axes of rotational symmetry. We propose the method to estimate the omnidirectional distribution of the scalar sources by measuring the interference between the antenna pairs while rotating the tensegrity array antenna around the rotational symmetry axis.
We present the configuration of the tensegrity array antenna as well as its deployment. We also propose an estimation method for the omnidirectional distribution of the scalar sources by rotational interferometry using the spherical harmonic expansion. We report the verification results of this estimation method using the similarity rule between electromagnetics and acoustics. For the verification, we constructed a six-channel array microphone and measured uncorrelated one-third octave bandpass noise (center frequencies of 1 k and 2 kHz, corresponding to 0.9 G and 1.8 GHz in radio-frequency conversion) emitted from multiple directions in an anechoic chamber by rotating the array microphone. The results indicate the ability to separate sources arriving simultaneously from multiple directions at 10 dB signal-to-noise ratio. This was achieved with the theoretical resolution of the interferometer. Finally, we discuss the development challenges and future works.
