High resolution general purpose D-layer experiment for EISCAT incoherent scatter radars using selected set of random codes
International audience The ionospheric D-layer is a narrow bandwidth radar target often with a very small scattering cross section. The target autocorrelation function can be obtained by transmitting a series of relatively short coded pulses and computing the correlation between data obtained from d...
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ftccsdartic:oai:HAL:hal-00317149v1 2023-11-12T04:16:38+01:00 High resolution general purpose D-layer experiment for EISCAT incoherent scatter radars using selected set of random codes Turunen, T. Westman, A. Häggström, I. Wannberg, G. EISCAT Scientific Association 2002 https://hal.science/hal-00317149 https://hal.science/hal-00317149/document https://hal.science/hal-00317149/file/angeo-20-1469-2002.pdf en eng HAL CCSD European Geosciences Union hal-00317149 https://hal.science/hal-00317149 https://hal.science/hal-00317149/document https://hal.science/hal-00317149/file/angeo-20-1469-2002.pdf info:eu-repo/semantics/OpenAccess ISSN: 0992-7689 EISSN: 1432-0576 Annales Geophysicae https://hal.science/hal-00317149 Annales Geophysicae, 2002, 20 (9), pp.1469-1477 [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/article Journal articles 2002 ftccsdartic 2023-10-21T23:07:42Z International audience The ionospheric D-layer is a narrow bandwidth radar target often with a very small scattering cross section. The target autocorrelation function can be obtained by transmitting a series of relatively short coded pulses and computing the correlation between data obtained from different pulses. The spatial resolution should be as high as possible and the spatial side lobes of the codes used should be as small as possible. However, due to the short pulse repetition period (in the order of milliseconds) at any instant, the radar receives detectable scattered signals not only from the pulse illuminating the D-region but also from 3?5 ambiguous-range pulses, which makes it difficult to produce a reliable estimate near zero lag of the autocorrelation function. A new experimental solution to this measurement problem, using a selected set of 40-bit random codes with 4 µs elements giving 600 m spatial resolution is presented. The zero lag is approximated by dividing the pulse into two 20-bit codes and computing the correlation between those two pulses. The lowest altitudes of the E-layer are measured by dividing the pulse into 5 pieces of 8 bits, which allows for computation of 4 lags. In addition, coherent integration of data from four pulses is used for obtaining separately the autocorrelation function estimate for the lowest altitudes and in cases when the target contains structures with a long coherence time. Design details and responses of the experiment are given, and analysed test data are shown. Article in Journal/Newspaper EISCAT Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
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Open Polar |
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Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
English |
topic |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
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[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences Turunen, T. Westman, A. Häggström, I. Wannberg, G. High resolution general purpose D-layer experiment for EISCAT incoherent scatter radars using selected set of random codes |
topic_facet |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
International audience The ionospheric D-layer is a narrow bandwidth radar target often with a very small scattering cross section. The target autocorrelation function can be obtained by transmitting a series of relatively short coded pulses and computing the correlation between data obtained from different pulses. The spatial resolution should be as high as possible and the spatial side lobes of the codes used should be as small as possible. However, due to the short pulse repetition period (in the order of milliseconds) at any instant, the radar receives detectable scattered signals not only from the pulse illuminating the D-region but also from 3?5 ambiguous-range pulses, which makes it difficult to produce a reliable estimate near zero lag of the autocorrelation function. A new experimental solution to this measurement problem, using a selected set of 40-bit random codes with 4 µs elements giving 600 m spatial resolution is presented. The zero lag is approximated by dividing the pulse into two 20-bit codes and computing the correlation between those two pulses. The lowest altitudes of the E-layer are measured by dividing the pulse into 5 pieces of 8 bits, which allows for computation of 4 lags. In addition, coherent integration of data from four pulses is used for obtaining separately the autocorrelation function estimate for the lowest altitudes and in cases when the target contains structures with a long coherence time. Design details and responses of the experiment are given, and analysed test data are shown. |
author2 |
EISCAT Scientific Association |
format |
Article in Journal/Newspaper |
author |
Turunen, T. Westman, A. Häggström, I. Wannberg, G. |
author_facet |
Turunen, T. Westman, A. Häggström, I. Wannberg, G. |
author_sort |
Turunen, T. |
title |
High resolution general purpose D-layer experiment for EISCAT incoherent scatter radars using selected set of random codes |
title_short |
High resolution general purpose D-layer experiment for EISCAT incoherent scatter radars using selected set of random codes |
title_full |
High resolution general purpose D-layer experiment for EISCAT incoherent scatter radars using selected set of random codes |
title_fullStr |
High resolution general purpose D-layer experiment for EISCAT incoherent scatter radars using selected set of random codes |
title_full_unstemmed |
High resolution general purpose D-layer experiment for EISCAT incoherent scatter radars using selected set of random codes |
title_sort |
high resolution general purpose d-layer experiment for eiscat incoherent scatter radars using selected set of random codes |
publisher |
HAL CCSD |
publishDate |
2002 |
url |
https://hal.science/hal-00317149 https://hal.science/hal-00317149/document https://hal.science/hal-00317149/file/angeo-20-1469-2002.pdf |
genre |
EISCAT |
genre_facet |
EISCAT |
op_source |
ISSN: 0992-7689 EISSN: 1432-0576 Annales Geophysicae https://hal.science/hal-00317149 Annales Geophysicae, 2002, 20 (9), pp.1469-1477 |
op_relation |
hal-00317149 https://hal.science/hal-00317149 https://hal.science/hal-00317149/document https://hal.science/hal-00317149/file/angeo-20-1469-2002.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1782333710942601216 |