As part of the “Inkjet-Printed Circuit Board Technology for User Terminal Antennas” R&D project, Harp Technologies designed a dual band L-band antenna for receiving and transmitting satellite data (voice, Internet, and multimedia data). The project was funded by the European Space Agency (ESA) and the project partners were the VTT Technical Research Centre of Finland and Premix Ltd. The antenna was realised by VTT using inkjet printing, which is a novel manufacturing technology for Printed Circuit Boards (PCBs) with great future potential. The benefits include, for example, easy design customisation for each customer.
The operational frequency bands of the antenna are 1.542 GHz and 1.664 GHz for downlink and uplink, respectively, with a bandwidth of 34 MHz for both. The antenna as designed consists of two substrate layers separated by an air gap and the size is 24 cm x 24 cm x 1.7 cm. The overall design requirements that were set were achieved and the measured total power patterns match very well with the simulated ones in terms of pattern shape, maximum gain, and sidelobe level. The measured maximum gains of 12.0 dBi (uplink) and 11.6 dBi (downlink) deviate only minimally from the simulated ones, which were 12.1 dBi and 11.8 dBi, respectively. The simulations were performed using the CST MICROWAVE STUDIO® software.
Harp Technologies Ltd has performed a study for the Finnish Meteorological Institute, Arctic Research Centre (FMI-ARC) to establish the requirements for a new satellite ground station in Sodankylä in Finnish Lapland. The aim of this receiving station is to receive remote sensing satellite data from selected satellites. The work included, for example, the definition of the technical requirements of the ground station, the identification and evaluation of potential alternative station models produced by commercial suppliers, the generation of cost estimates, and the evaluation of the receiving station’s integration into the other systems of FMI-ARC. The most important technical requirement (figure of merit) was the G/T (gain over noise temperature), which was determined. In order to define the G/T requirement, it was necessary to accurately define the link budget for the satellites of interest. The G/T is strongly dependent on the size of the receiving antenna, which in turn has a major impact on the cost. Thus, the specification of the receiving station’s technical requirements was an optimisation task to minimise the cost for a given quality and statistical availability of the satellite data.
The results of Harp Technologies’ work were used by FMI-ARC for evaluation, planning, and budgeting purposes. After the funding decision, Harp Technologies supported FMI-ARC in its preparation of detailed technical requirements specifications for the Request for Quotation and finally, assisted in the evaluation of the technical proposals of the potential suppliers. After construction, FMI-ARC commissioned the defined X-band high-capacity satellite receiving station in Sodankylä in 2011.
Harp Technologies has developed a stepped-frequency, fully polarimetric radar system (SodScat, Sodankylä Scatterometer) for the Finnish Meteorological Institute (FMI), for scientific use. The SodScat radar is operated in the Arctic Space Centre of FMI in Sodankylä, in Finnish Lapland. SodScat is a ground-based instrument mountable on e.g. tower platforms, enabling measurements of the ground surface at a slanted angle. The main purpose of SodScat is to enable detailed investigations of the microwave signatures of soil, vegetation, and snow cover through a wide frequency range (1-10 GHz) and at all four polarizations (VV, HH, VH, HV), with applications ranging from the detection of soil freezing and thawing to the measurement of snow mass. SodScat can also serve as a ground-based reference instrument for various Earth Observing satellite sensors (e.g. Sentinel-1, TerraSAR-X). The system includes internal calibration and all the main functions can be controlled remotely via a control computer. The system has been designed for the harsh environmental conditions of Sodankylä (-50ºC…+30ºC; heavy snowfall and wind) and it includes internal temperature and humidity control. The size of SodScat is 82 x 60 x 61 cm3 (antennas excluded).
To participate in and contribute to the academic and industrial exchange, Harp Technologies is an active member of the research community. This has resulted in the following publications on publicly funded research:
J. Lahtinen, J. Uusitalo, T. Ruokokoski, and J. Ruoskanen, “Comparison of polarimetric algorithm with other algorithms in detecting Radio Frequency Interference,” IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, vol. 10, no 7, pp. 3087-3095, July 2017.
J. Lahtinen and M. T. Hallikainen, “Retardation plate for the calibration of a fully polarimetric radiometer: Determination of characteristics,” IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, vol. 10, no 7, pp. 3046-3054, July 2017.
J. Seppänen, J. Kainulainen, J. Heiskanen, J. Praks, and M. Hallikainen “Measurements of boreal coniferous forest soil and humus with an airborne radiometer,” IEEE Journal of Selected Topics in Applied Earth Observation and Remote Sensing, Vol. 9, No. 7, pp. 3219-3228, July 2016.
M. Martín-Neira, R. Oliva, I. Corbella, F. Torres, N. Duffo, I. Durán, J. Kainulainen, J. Closa, A. Zurita, F. Cabot, A. Khazaal, E. Anterrieu, J. Barbosa, G. Lopes, J. Tenerelli, R. Díez-García, J. Fauste, F. Martín-Porqueras, V. González, A. Turiel, S. Delwart, R. Crapolicchio, and M. Suess, “SMOS instrument performance and calibration after six years in orbit,” Remote Sensing of Environment, Vol. 180, pp. 19-39, July 2016.
M. Martín-Neira, R. Oliva, I. Corbella, F. Torres, N. Duffo, I. Duran, J. Kainulainen, J. Closa, A. Zurita, F. Cabot, A. Khazaal, E. Anterrieu, J. Barbosa, G. Lopes, J. Tenerelli, R. Diez-Garcia, J. Fauste, V. Gonzalez-Gambau, A. Turiel, S. Delwart, R. Crapolicchio, and M. Suess, “SMOS instrument performance and calibration after 6 years in orbit,” Proc. 2016 IEEE International Geoscience and Remote Sensing Symposium, pp. 2040-2042. Beijing, China, 2016.
H. Nguyen, T. Ruokokoski, P. Piironen, and J. Lahtinen, ”Higher order ferrite junction switch for radiometer calibration,” Proc. 2016 Global Symposium on Millimeter Waves (GSMM) & ESA Workshop on Millimetre-Wave Technology and Applications, pp. 1-4. Espoo, Finland, 2016.
J. Lahtinen, J. Uusitalo, T. Ruokokoski, and J. Ruoskanen, ”Evaluation and comparison of RFI detection algorithms,” Proc. 14th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment (MicroRad 2016), pp. 62-67. Espoo, Finland, 2016.
J. Lahtinen and M. Hallikainen, “Fully polarimetric radiometer calibration: Determining retardation plate’s phase shift,” Proc. 14th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment (MicroRad 2016), pp. 175-180, Espoo, Finland, 2016.
N. Skou, S. S. Kristensen, A. Kovanen, and J. Lahtinen, ”Performance of a processor for on-board RFI detection and mitigation in MetOp-SG radiometers,” Proc. 14th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment (MicroRad 2016), pp. 58-61. Espoo, Finland, 2016.
A. Colliander, E. Dinnat, D. Le Vine, C. S. Chae, J. Kainulainen, “Assessing long term stability of SMOS zero-baseline antenna temperature using the Aquarius antenna temperature simulator,” IEEE Geoscience and Remote Sensing Letters, Vol. 12, No. 8, pp. 1680-1684, Dec. 2015.
N. Skou, S. S. Kristensen, A. Kovanen, J. Lahtinen, “Processor breadboard for on-board RFI detection and mitigation in MetOp-SG radiometers,” IEEE 2015 International Geoscience and Remote Sensing Symposium Proceedings, pp. 1445-1448. Milan, Italy, 2015.
J. Kainulainen, J. Uusitalo, M. Hansen, M. Pedersen, J. Lahtinen, M. Martin-Neira, “Assessment of radiometer concepts for advanced SST/OVW mission,” Proc. Advanced RF Sensors and Remote Sensing Instruments 2014 & Ka-band Earth Observation Radar Mission 2014. Noordwijk, the Netherlands, 2014.
A. Colliander, C. S. Chae, J. Kainulainen, E. Dinnat, F. Torres, I. Corbella, R. Oliva, and M. Martin-Neira, “Advances in calibration of the SMOS zero-baseline radiometers,” Proc. 13th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment (MicroRad) 2014, pp. 201-204. Pasadena, CA, USA, 2014.
N. Skou, S. S. Kristensen, A. Kovanen, J. Lahtinen, “Digital processor breadboard for RFI detection and mitigation in spaceborne radiometers,” IEEE 2014 International Geoscience and Remote Sensing Symposium Proceedings, pp. 211-214, Québec City, Canada, 2014.
J. Ruoskanen, T. Ruokokoski, and J. Lahtinen, “Enhanced detection of weak radar pulses using kurtosis statistics,” Proc. IET International Conference on Radar Systems (Radar 2012), pp. 1-5. Glasgow, UK, 2012.
N. Skou, S. S. Kristensen, T. Ruokokoski, J. Lahtinen, “On-board digital RFI and polarimetry processor for future spaceborne radiometer systems,” IEEE 2012 International Geoscience and Remote Sensing Symposium Proceedings, pp. 3423 – 3426. Munich, Germany, 2012.
G. Alberti, A. Memoli, G. Pica, M. R. Santovito, B.Buralli, J.E.Charlton, S. Varchetta, M. Brandt, J. Lahtinen, S. D’addio, and V. Kangas, “Analysis of the performance of the Microwave Imager radiometer for MetOp Second Generation,” Proc. 2012 12th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment (MicroRad), pp. 1-4. Frascati, Italy, 2012.
J. Lahtinen, T. Ruokokoski, S. S. Kristensen, N. Skou, “Intelligent digital back-end for real-time RFI detection and mitigation in microwave radiometry,” Proc. Third Workshop on Advanced RF Sensors and Remote Sensing Instruments (ARSI). Noordwijk, The Netherlands, 2011.
J.-C. Orlhac, H. Roquet, A. Bentamy, C. Prigent, F. Aires, K. Atkinson, G. Sykes, J. Lahtinen, N. Skou, E. Anterrieu, and C. Donlon, “High Resolution Microwave Wind and Temperature (MICROWAT) Mission Concept Study,” Proc. Third Workshop on Advanced RF Sensors and Remote Sensing Instruments (ARSI). Noordwijk, The Netherlands, 2011.
J. Kainulainen, J. Lemmetyinen, K. Rautiainen, A. Colliander, J. Uusitalo, and J. Lahtinen, “Error propagation in calibration networks of synthetic aperture radiometers,” IEEE Transactions on Geoscience and Remote Sensing, vol. 47, no 9, pp. 3140-3150, Sept. 2009.
J. Lahtinen, P. Piironen, A. Colliander, and M. Martin-Neira, “Improved Receiver Architecture for Future L-Band Radiometer Missions,” IEEE 2007 International Geoscience and Remote Sensing Symposium Proceedings, pp. 5247-5250. Barcelona, Spain, 2007.
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