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Relating Sentinel-1 interferometric coherence to mowing events on grasslands

Tamm, Tanel; Zalite, Karlis LU ; Voormansik, Kaupo and Talgre, Liina (2016) In Remote Sensing 8(10).
Abstract

In this study, the interferometric coherence calculated from 12-day Sentinel-1 image pairs was analysed in relation to mowing events on agricultural grasslands. Results showed that after a mowing event, median VH (vertical transmit, horizontal receive) and VV (vertical transmit, vertical receive) polarisation coherence values were statistically significantly higher than those from before the event. The shorter the time interval after the mowing event and the first interferometric acquisition, the higher the coherence. The coherence tended to stay higher, even 24 to 36 days after a mowing event. Precipitation caused the coherence to decrease, impeding the detection of a mowing event. Given the three analysed acquisition geometries, it... (More)

In this study, the interferometric coherence calculated from 12-day Sentinel-1 image pairs was analysed in relation to mowing events on agricultural grasslands. Results showed that after a mowing event, median VH (vertical transmit, horizontal receive) and VV (vertical transmit, vertical receive) polarisation coherence values were statistically significantly higher than those from before the event. The shorter the time interval after the mowing event and the first interferometric acquisition, the higher the coherence. The coherence tended to stay higher, even 24 to 36 days after a mowing event. Precipitation caused the coherence to decrease, impeding the detection of a mowing event. Given the three analysed acquisition geometries, it was concluded that afternoon acquisitions and steeper incidence angles were more useful in the context of this study. In the case of morning acquisitions, dew might have caused a decrease of coherence for mowed and unmowed grasslands. Additionally, an increase of coherence after a mowing event was not evident during the rapid growth phase, due to the 12-day separation between the interferometric acquisitions. In future studies, six-day pairs utilising Sentinel-1A and 1B acquisitions should be considered.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Agriculture, Grasslands, Interferometric coherence, Mowing detection, Precipitation estimates, SAR, Synthetic aperture radar, Weather radar
in
Remote Sensing
volume
8
issue
10
publisher
MDPI AG
external identifiers
  • scopus:85019771173
  • wos:000387357300016
ISSN
2072-4292
DOI
10.3390/rs8100802
language
English
LU publication?
yes
id
ba062cb0-a9aa-40db-ba09-516e304108f1
date added to LUP
2017-06-13 10:17:13
date last changed
2017-09-18 11:40:20
@article{ba062cb0-a9aa-40db-ba09-516e304108f1,
  abstract     = {<p>In this study, the interferometric coherence calculated from 12-day Sentinel-1 image pairs was analysed in relation to mowing events on agricultural grasslands. Results showed that after a mowing event, median VH (vertical transmit, horizontal receive) and VV (vertical transmit, vertical receive) polarisation coherence values were statistically significantly higher than those from before the event. The shorter the time interval after the mowing event and the first interferometric acquisition, the higher the coherence. The coherence tended to stay higher, even 24 to 36 days after a mowing event. Precipitation caused the coherence to decrease, impeding the detection of a mowing event. Given the three analysed acquisition geometries, it was concluded that afternoon acquisitions and steeper incidence angles were more useful in the context of this study. In the case of morning acquisitions, dew might have caused a decrease of coherence for mowed and unmowed grasslands. Additionally, an increase of coherence after a mowing event was not evident during the rapid growth phase, due to the 12-day separation between the interferometric acquisitions. In future studies, six-day pairs utilising Sentinel-1A and 1B acquisitions should be considered.</p>},
  articleno    = {802},
  author       = {Tamm, Tanel and Zalite, Karlis and Voormansik, Kaupo and Talgre, Liina},
  issn         = {2072-4292},
  keyword      = {Agriculture,Grasslands,Interferometric coherence,Mowing detection,Precipitation estimates,SAR,Synthetic aperture radar,Weather radar},
  language     = {eng},
  month        = {10},
  number       = {10},
  publisher    = {MDPI AG},
  series       = {Remote Sensing},
  title        = {Relating Sentinel-1 interferometric coherence to mowing events on grasslands},
  url          = {http://dx.doi.org/10.3390/rs8100802},
  volume       = {8},
  year         = {2016},
}