Zobrazeno 1 - 10
of 11
pro vyhledávání: '"Markku Markkanen"'
Publikováno v:
Journal of Inverse and Ill-posed Problems. 27:225-240
We consider inverse problems in which the unknown target includes sharp edges, for example interfaces between different materials. Such problems are typical in image reconstruction, tomography, and other inverse problems algorithms. A common solution
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::42703c64b33484a2515e0e16847e3771
https://doi.org/10.1515/jiip-2017-0048
https://doi.org/10.1515/jiip-2017-0048
We introduce non-stationary Matern field priors with stochastic partial differential equations, and construct correlation length-scaling with hyperpriors. We model both the hyperprior and the Matern prior as continuous-parameter random fields. As hyp
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::df8e287aa9d0a25133d8df59407e2f3b
http://hdl.handle.net/10044/1/66155
http://hdl.handle.net/10044/1/66155
Autor:
Kirsti Kauristie, Liisa Juusola, Johannes Norberg, Lassi Roininen, Tero Raita, Thomas Ulich, Markku Markkanen, Antti Kero
Publikováno v:
Geoscientific Instrumentation, Methods and Data Systems, Vol 5, Iss 1, Pp 263-270 (2016)
Sodankylä Geophysical Observatory has been operating a receiver network for ionospheric tomography and collecting the produced data since 2003. The collected data set consists of phase difference curves measured from COSMOS navigation satellites fro
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::4c0dc184d08f9d3f6ad4b8db1587812b
https://www.geosci-instrum-method-data-syst.net/5/263/2016/
https://www.geosci-instrum-method-data-syst.net/5/263/2016/
Publikováno v:
Journal of Applied Meteorology. 44:1375-1390
Based on the measurement principles used on incoherent scatter radars, the authors have developed the Simultaneous Multiple Pulse Repetition Frequency (SMPRF) code that is intended to solve the range–Doppler dilemma and that can be used with modern
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::eb2200c5611c99671449b6eb3d62d57e
https://doi.org/10.1175/jam2288.1
https://doi.org/10.1175/jam2288.1
Publikováno v:
AIP Conference Proceedings.
In this paper we present an efficient implementation of an algorithm for reconstructing a 3D volume from limited angle projection data, based on statistical inversion theory. We demonstrate the strength of the method for detecting structural defects
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::5ff08bccf71eed87bb2b0923114b987d
https://doi.org/10.1063/1.4865042
https://doi.org/10.1063/1.4865042
Publikováno v:
Radio Science. 32:2271-2282
Incoherent scatter radar autocorrelation function estimates produced by alternating codes are found to contain significant correlations between different lags and different heights. While no correlations are caused by the background thermal noise, th
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::79aeae1847d1159fb963adca68ca016c
https://doi.org/10.1029/97rs02556
https://doi.org/10.1029/97rs02556
Publikováno v:
Scopus-Elsevier
The stochastic inversion method in ionospheric radiotomography is reviewed with a special emphasis on regularization used in the inversion process. Regularization is used both for preventing vigorous point-to-point oscillations and for controlling th
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::646bd89ce9c9494bdd0f81d3d32e4f70
https://doi.org/10.1029/97rs02915
https://doi.org/10.1029/97rs02915
Publikováno v:
Radio Science. 32:605-616
In satellite ray tomography the measurements are samples of Radon transform of the ionospheric electron density. Regardless of the practical numerical method applied, the goal of tomographic inversion is to calculate the inverse of the Radon transfor
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::88e38b178426219085233118f7d48b11
https://doi.org/10.1029/96rs03446
https://doi.org/10.1029/96rs03446
Autor:
Markku Markkanen, Tuomo Nygrén
Publikováno v:
Radio Science. 32:9-18
This paper is the second one in a series explaining a new search method of long alternating codes for incoherent scatter radars. The first paper explains the general idea of the method in terms of a special game of dominoes. This second paper gives a
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::67d12ccf7e533f25e2867504dbce3c7d
https://doi.org/10.1029/96rs03117
https://doi.org/10.1029/96rs03117
Autor:
Tuomo Nygrén, Markku Markkanen
Publikováno v:
Radio Science. 32:1-8
A new extremely effective method of finding strong alternating codes for incoherent scatter radars has been invented. The power of this method is described by the fact that the longest code known at the moment contains 4,194,304 bits, whereas the old
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::03206f6bc3bbd2f17676d6f4e0df8bf4
https://doi.org/10.1029/96rs03118
https://doi.org/10.1029/96rs03118