A decade of Planck
Understanding Big Bang with reflector antennas
The Planck Telescope was launched in 2009 and operated until 2013, with the purpose to measure and collect data from the Cosmic Microwave Background originating from the Big Bang 14 billion years ago.
Before its launch, 15 years of analysis and design of the instrument had preceded at TICRA. Planck’s low-frequency instrument (LFI) from 30 to 70 GHz and high-frequency instrument (HFI) from 100 to 857 GHz consisted of a dual-reflector antenna and two separate feed arrays: An array of conventional corrugated horns for the LFI and an array of bolometer horns for the HFI. A baffle shielded the reflector antenna from stray light from sources outside the main beam directions.
TICRA was in charge of computing full-sphere antenna patterns for all feeds all the way up to 857 GHz. Due to the challenging geometry and the extremely high frequency, numerical methods were developed by TICRA’s engineers to deal with the scattering at the high frequencies, which was not feasible with Physical Optics. These developments later became the Multi-GTD add-on to GRASP. Reflections and diffractions up to seventh order were included in the model. Only much later, in 2015, the Multi-GTD results were compared to and validated against full-wave simulations with TICRA’s very efficient multi-level fast multipole method (MLFMM) at 30 GHz.
After the successful launch, TICRA continued its involvement by assisting with retrieval of the reflector geometry and focal plane alignment, using in-flight measurements of the antenna beams. This was needed to compute the response of the Planck detectors and led to filtering and noise reduction of the received signals.
Planck was a mission with outstanding scientific results and technological developments, which gave rise to numerous publications in astronomy and astrophysics journals as well as new numerical algorithms developed by TICRA.
