Sodsar: A tower-based 1–10 ghz sar system for snow, soil and vegetation studies

Jorge Jorge Ruiz*, Risto Vehmas, Juha Lemmetyinen, Josu Uusitalo, Janne Lahtinen, Kari Lehtinen, Anna Kontu, Kimmo Rautiainen, Riku Tarvainen, Jouni Pulliainen, Jaan Praks

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

7 Citations (Scopus)
58 Downloads (Pure)


We introduce SodSAR, a fully polarimetric tower-based wide frequency (1–10 GHz) range Synthetic Aperture Radar (SAR) aimed at snow, soil and vegetation studies. The instrument is located in the Arctic Space Centre of the Finnish Meteorological Institute in Sodankylä, Finland. The system is based on a Vector Network Analyzer (VNA)-operated scatterometer mounted on a rail allowing the formation of SAR images, including interferometric pairs separated by a temporal baseline. We present the description of the radar, the applied SAR focusing technique, the radar calibration and measurement stability analysis. Measured stability of the backscattering intensity over a three-month period was observed to be better than 0.5 dB, when measuring a target with a known radar cross section. Deviations of the estimated target range were in the order of a few cm over the same period, indicating also good stability of the measured phase. Interforometric SAR (InSAR) capabilities are also discussed, and as a example, the coherence of subsequent SAR acquisitions over the observed boreal forest stand are analyzed over increasing temporal baselines. The analysis shows good conservation of coherence in particular at L-band, while higher frequencies are susceptible to loss of coherence in particular for dense vegetation. The potential of the instrument for satellite calibration and validation activities is also discussed.

Original languageEnglish
Article number6702
Pages (from-to)1-18
Number of pages18
JournalSensors (Switzerland)
Issue number22
Publication statusPublished - 2 Nov 2020
MoE publication typeA1 Journal article-refereed


  • Boreal forest
  • Insar
  • Radiometric calibration
  • Scatterometer
  • SodSAR
  • Synthetic aperture radar
  • Temporal coherence
  • Vector network analyzer


Dive into the research topics of 'Sodsar: A tower-based 1–10 ghz sar system for snow, soil and vegetation studies'. Together they form a unique fingerprint.

Cite this