Brian Ellison

Receivers for ALMA: preliminary design concepts

The Atacama Large Millimeter Array (ALMA), a joint project between Europe and the U.S. and at present in its design and development phase, is a major new ground based telescope facility for millimeter and submillimeter astronomy. Its huge collecting area (7000 m2), sensitive receivers and location at one of the driest sites on Earth will make it a unique instrument. We present preliminary design concepts for the overall receiver configuration. Optics and cryostat design concepts from OSO, OVRO, RAL, IRAM, NRAO and SRON and their main features are described.

Development of a compact sub-millimetre wave SIS receiver for terrestrial atmospheric sounding

A compact 500 GHz SIS heterodyne radiometer is currently being developed at the Rutherford Appleton Laboratory (RAL), UK. The radiometer can be integrated with a new state-of-the-art balloon borne terahertz and sub-millimetre wave limb sounder (TELIS) and performs remote sounding of key molecular constituents within the Earths atmosphere. The paper presents the design concept of the receiver and current status of development.

Recent progress in the Elegant Breadboard supra-THz activities for LOCUS and a view to an astronomy application

We report on ongoing technology activities on the Elegant Breadboard for the LOCUS telescope and its 1.15THz receiver. LOCUS is a Low-Earth orbit small satellite (150kg category) with the objective of linking observations of climate, the upper atmosphere and space weather by performing simultaneous high spectral resolution measurements of molecular signatures of molecules which drive the thermal exchange in the highest layers of our atmosphere. These measurements are performed both in the THz frequency region and in a photometric narrow-band near and mid-IR channels allowing to decouple molecular abundances from temperature and pressure profiles. The elegant breadboard under development will reproduce representative optics and explore the thermal implications of a compact optical-bench with a small cryo-cooler and radiator stage for a small LEO satellite. An extensive test programme will be undertaken to raise the payload and receiver system and we will seek opportunities to test the system in an observational campaign. Technology developments will benefit future technology activities related to both a future Earth-Orbit mission and potential astronomy missions.

High sensitivity broadband 360 GHz front-end receiver for TeraSCREEN

The development is described of a 360 GHz sub-harmonic mixer for the active and passive sub-systems of the TeraSCREEN security scanner by STFC RAL Space. The mixers operate as predicted with state-of-the-art performance. A radiometer sensitivity measurement also shows the devices have outstanding performance.

Upgrade of the RAL solid state cloud radar

The activities for upgrading the Rutherford Appleton Laboratory millimetre wave radar cloud profiler are presented. The motivation for these activities and the approach are introduced. First results of these activities are presented.

The LOw Cost Upper atmosphere Sounder: The "elegant breadboard" programme

The LOw Cost Upper atmosphere Sounder (LOCUS) mission has a core objective of probing the Earths meso-sphere and low thermosphere (MLT) region using THz receivers combined with an infrared (IR) filter radiometer. This will give the first comprehensive data on the energy balance and chemical processes in the MLT from direct detection, including the important atomic oxygen which until now has never been mapped by remote sensing measurements. The payload and mission design concept has very recently, and very successfully, concluded an ESA sponsored phase A0 study, led by SSTL. It is essential to build upon this success and to maintain the mission momentum towards achieving a high readiness level (TRL) and eventual flight. A key step in this process is the demonstration and proof of operation of the THz payload in a representative environment (towards TRL 6). We therefore have begun working on a hi-fidelity breadboard of the LOCUS payload suitable for both extensive laboratory and environmental testing, and with a potential for deployment on a high-altitude platform, such as NASAs Global Hawk. The latter will prove the system technical operation in a closely representative environment, and will return valuable and useful scientific data. The breadboard will consist of the system primary antenna; optical bench; one or more THz receivers; back-end electronics, and a physical realisation of the spacecraft payload bay. An extensive test programme will be undertaken to raise the payload and receiver system towards level 6, and we will seek opportunities to test the system in an observational campaign.

Dopplerising the STFC/RAL radar cloud profiler

An approach for re-designing and adding Doppler capability to the STFC RAL 94 GHz Radar Cloud Profiler based on solid state components is described. The current design is shown, and the approach to the re-design is laid out. Following that, the anticipated phases to realisation of the re-design is explained. Results of the first phase will be presented at the symposium.