498 research outputs found
Digital-beamforming array antenna technologies for future ocean-observing satellite missions
Existing passive microwave radiometers that are used for ocean observations are limited in spatial resolution and geographic coverage, due to the limitations of traditional antenna technologies using mechanically-scanning reflectors and horn-type feeds. Future ocean observation missions call for new solutions, such as digitally-beamforming array feeds (DBAFs) as well as stationary and more complex reflectors. Our studies demonstrate that DBAFs can overcome the physically fundamental limitations of traditional horn feeds, and are capable of meeting all the challenging requirements for the next-generation instruments
Advanced modelling of the Planck-LFI radiometers
The Low Frequency Instrument (LFI) is a radiometer array covering the 30-70
GHz spectral range on-board the ESA Planck satellite, launched on May 14th,
2009 to observe the cosmic microwave background (CMB) with unprecedented
precision. In this paper we describe the development and validation of a
software model of the LFI pseudo-correlation receivers which enables to
reproduce and predict all the main system parameters of interest as measured at
each of the 44 LFI detectors. These include system total gain, noise
temperature, band-pass response, non-linear response. The LFI Advanced RF Model
(LARFM) has been constructed by using commercial software tools and data of
each radiometer component as measured at single unit level. The LARFM has been
successfully used to reproduce the LFI behavior observed during the LFI
ground-test campaign. The model is an essential element in the database of LFI
data processing center and will be available for any detailed study of
radiometer behaviour during the survey.Comment: 21 pages, 15 figures, this paper is part of the Prelaunch status LFI
papers published on JINST:
http://www.iop.org/EJ/journal/-page=extra.proc5/jins
Lily Day, Wednesday, March 4, 1964
Comments on past research in Ohio on Lilies / D. C. Kiplinger -- Lily investigations / Abdel-Alim M. Shoushan -- Further studies on causes and control of leaf scorch in Croft Easter lily / N. W. Stuart, William Skou, and D. C. Kiplinger -- Fertilizer and lime affect amount of leaf scorch in Croft Easter lilies / Neil W. Stuart, K. S. Nelson and D. C. Kiplinger -- Comparative development of Ace and Nellie White lilies / Dennis Rider and D. C. Kiplinger -- Experiments with potted lilies, 1961-1962 / D. C. Kiplinger, Robert O. Miller, Howard Jones, and Dennis Rider -- Lily culture and timing for Easter, 1964 / D. C. Kiplinger and Robert O. Miller -- High temperature treatment of Easter lily bulbs / Robert O. Miller and D. C. Kiplinger -- An investigation of causes of variation in the growth of commercial and experimental lilies / Robert O. Miller and D. C. Kiplinger -- Applying terraclor with or without dexon / D. C. Kiplinger, Robert O. Miller and Leonard J. Her
- …