Remotely operated infrared radiometer for the measurement of atmospheric water vapor

Naylor, David; Gom, Brad; Schofield, Ian; Tompkins, G. J.; Chapman, Ian M.

doi:10.1117/12.450553

Cited by 7 publications

(7 citation statements)

References 4 publications

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“…IRMA data collection scans typically generate around 500 bytes every 4 seconds. 1 It is possible to exhaust the non-volatile memory resources on a Rabbit microcontroller module in a short amount of time, if the program writer is not careful. Since the Rabbit is a diskless system and relies on its flash memory chip for permanent storage, including storage space for its executable program, simulated disk file systems can be no larger than the remaining memory.…”

Section: Hardware / Software Design Considerationsmentioning

confidence: 99%

“…The resulting data will then be used to correct phase distortion contained in the signal data and thereby increase the angular resolution of the telescope. 1 IRMA is being developed with the goal of performing phase correction for the Atacama Large Millimeter Array (ALMA), which will be the world's most powerful ground-based telescope, when completed early in the next decade.…”

Section: Introductionmentioning

confidence: 99%

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Instrumentation control using the Rabbit 2000 embedded microcontroller

Schofield

Naylor

2004

SPIE Proceedings

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Embedded microcontroller modules offer many advantages over the standard PC such as low cost, small size, low power consumption, direct access to hardware, and if available, access to an efficient preemptive real-time multitasking kernel. Typical difficulties associated with an embedded solution include long development times, limited memory resources, and restricted memory management capabilities. This paper presents a case study on the successes and challenges in developing a control system for a remotely controlled, Alt-Az steerable, water vapour detector using the Rabbit 2000 family of 8-bit microcontroller modules in conjunction with the MicroC/OS-II multitasking real-time kernel.

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Section: Hardware / Software Design Considerationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Instrumentation control using the Rabbit 2000 embedded microcontroller

Schofield

Naylor

2004

SPIE Proceedings

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“…5 In summary, it consists of a 35 x 22 x 19 cm aluminium box weighing just over 13 kg. The box contains a Honeywell-Hymatic Stirling cycle cooler, an attached vacuum vessel containing the 20 µm detector and long pass filter, a chopper blade, a 10 cm off-axis parabolic mirror, a warm blackbody calibration source and all the required power supplies, electronics and microprocessor needed to operate the instrument.…”

Section: Introductionmentioning

confidence: 99%

Initial operations of an water vapour monitor (IRMA) at Gemini South, Las Campanas Observatories, and in the TMT site testing role

Phillips

Naylor

2006

SPIE Proceedings

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Since February 2005, an Infrared Radiometer for Millimeter Astronomy (IRMA) has been measuring precipitable water vapour levels in Chile at the Gemini South site on Cerro Pachon with a second unit added at the Las Campanas observatories site in August 2005. We have also started data collection with three additional IRMA units at three locations for the TMT site testing effort. After a number of technical modifications to ensure reliable operations at much lower sites than IRMA was designed for, 6 months of near continuous pwv data have been collected at both existing telescope sites and several months of data at TMT candidate locations. These data are enabling us to compare the sites on diurnal as well as seasonal timescales.

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“…In our application, an infrared radiometer operating at ∼20 μm, [1,2], zinc selenide (ZnSe) meets nearly all the above requirements, however, it suffers from large reflective surface losses due to its high refractive index, n ZnSe 2:46, which results in a transmission of ∼60% in the 10-20 μm range. We have therefore developed a simple, yet effective method for antireflection coating ZnSe that raises its transmission to over 90% in this spectral range.…”

Section: Introductionmentioning

confidence: 99%