A short history of geophysical radar at Arecibo Observatory

Mathews, J. D.

doi:10.5194/hgss-4-19-2013

Cited by 21 publications

(16 citation statements)

References 71 publications

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“…The incoherent scatter technique was developed by a number of investigators 1 – 11 . A review of early ionospheric research at Arecibo was given by Mathews 12 .…”

Section: Introductionmentioning

confidence: 99%

Major upwelling and overturning in the mid-latitude F region ionosphere

et al. 2018

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Profiles of the electron number density in the ionosphere are observed at the Arecibo Radio Observatory in Puerto Rico on a regular basis. Here, we report on recent observations showing anomalous irregularities in the density profiles at altitudes >~300 km. The irregularities occurred during a period of “mid-latitude spread F,” a space-weather phenomenon relatively common at middle latitudes in summer months characterized by instability and electron density irregularities in the bottomside of the ionospheric F layer. Remarkably, electron density irregularities extended well above the layer, through the ionization peak and into the topside which is regarded as being stable. Neither the neutral atmosphere nor the ionosphere is thought to be able to support turbulence locally at this altitude. A numerical simulation is used to illustrate how a combination of atmospheric and plasma dynamics driven at lower altitudes could explain the phenomenon.

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“…The incoherent scatter technique was developed by a number of investigators 1 – 11 . A review of early ionospheric research at Arecibo was given by Mathews 12 .…”

Section: Introductionmentioning

confidence: 99%

Major upwelling and overturning in the mid-latitude F region ionosphere

et al. 2018

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“…The 55-year history of terrestrial astronomical observatory radars, such as Arecibo [40], that transmit circular polarization and receive through either circular or linear polarizations provides a background for EO SAR researchers. The HCP mode takes the same approach.…”

Section: Hcp Sar and Rcmmentioning

confidence: 99%

Hybrid Compact Polarimetric SAR for Environmental Monitoring with the RADARSAT Constellation Mission

Brisco¹,

Mahdianpari

Mohammadimanesh

2020

Remote Sensing

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Canada’s successful space-based earth-observation (EO) radar program has earned widespread and expanding user acceptance following the launch of RADARSAT-1 in 1995. RADARSAT-2, launched in 2007, while providing data continuity for its predecessor’s imaging capabilities, added new polarimetric modes. Canada’s follow-up program, the RADARSAT Constellation Mission (RCM), launched in 2019, while providing continuity for its two predecessors, includes an innovative suite of polarimetric modes. In an effort to make polarimetry accessible to a wide range of operational users, RCM uses a new method called hybrid compact polarization (HCP). There are two essential elements to this approach: (1) transmit only one polarization, circular; and (2) receive two orthogonal polarizations, for which RCM uses H and V. This configuration overcomes the conventional dual and full polarimetric system limitations, which are lacking enough polarimetric information and having a small swath width, respectively. Thus, HCP data can be considered as dual-pol data, while the resulting polarimetric classifications of features in an observed scene are of comparable accuracy as those derived from the traditional fully polarimetric (FP) approach. At the same time, RCM’s HCP methodology is applicable to all imaging modes, including wide swath and ScanSAR, thus overcoming critical limitations of traditional imaging radar polarimetry for operational use. The primary image data products from an HCP radar are different from those of a traditional polarimetric radar. Because the HCP modes transmit circularly polarized signals, the data processing to extract polarimetric information requires different approaches than those used for conventional linearly polarized polarimetric data. Operational users, as well as researchers and students, are most likely to achieve disappointing results if they work with traditional polarimetric processing tools. New tools are required. Existing tutorials, older seminar notes, and reference papers are not sufficient, and if left unrevised, could succeed in discouraging further use of RCM polarimetric data. This paper is designed to provide an initial response to that need. A systematic review of studies that used HCP SAR data for environmental monitoring is also provided. Based on this review, HCP SAR data have been employed in oil spill monitoring, target detection, sea ice monitoring, agriculture, wetland classification, and other land cover applications.

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“…The Arecibo heater has undergone several major changes since the first experiments were performed there in 1970. Mathews [2013] gives a historical description of the heating facility and the radar for the fiftieth anniversary of the observatory. Although the heater has always had relatively modest power compared to some of the other facilities, Arecibo with its more than 100 times more sensitive radar compared to most other incoherent scatter radars [Isham et al, 2000], together with the fact that many HF-induced plasma wave interactions require only modest field strengths to be excited, has made results from this famous facility extremely important.…”

Section: Arecibomentioning

confidence: 99%