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Dr. Andreas Colliander

Research Scientist

About

Bio

Dr. Andreas Colliander is a Research Scientist in the Microwave Instrument Science group at JPL. He has been at JPL since 2008, when he started working on NASA's SMAP (Soil Moisture Active Passive) mission. He is responsible for the calibration and validation (cal/val) of the SMAP geophysical products, which includes coordinating a large international coalition of participants to collect ground truth data, leading field experiments deploying airborne instruments along with intensive manual measurements, and assessing the performance of the data products. He is also a member of the SMAP Science Team. Besides the cal/val work for SMAP, Dr. Colliander has participated in and led several other projects focused on developing microwave remote sensing techniques, calibrating airborne and spaceborne microwave radiometers, and utilizing microwave measurements to learn more about the Earth's geophysical processes. One of Dr. Colliander's focus areas is developing ice sheet meltwater estimation using microwave radiometers, including developing this capability for European Space Agency's (ESA) upcoming CIMR (Copernicus Imaging Microwave Radiometer) mission. He also serves as a member of the CIMR Mission Advisory Group.

Dr. Colliander has been working on remote sensing research and development projects since 2000, when he joined the Laboratory of Space Technology at Helsinki University of Technology (currently Aalto University), Finland, as a summer intern. That continued to his Ph.D. work, where his main project was related to instrument development for ESA's SMOS (Soil Moisture and Ocean Salinity) SMOS satellite. After his Doctoral dissertation, he joined ESA's European Space Research and Technology Centre (ESTEC) as a Postdoctoral Research Fellow in 2007, where he worked on concepts for microwave radiometer measurement from satellites.

Education

  • Ph.D., Electrical Engineering, Helsinki University of Technology (Aalto University), 2007
  • M.S., Electrical Engineering, Helsinki University of Technology (Aalto University), 2002

Research Interests

Microwave remote sensing techniques, especially to solve climate change related questions in land and cryosphere hydrology and oceanography.

Experience

Professional Experience

  • Jet Propulsion Laboratory, California Institute of Technology (2008 - Present)
    • Research Scientist
       
  • European Space Agency, European Space and Technology Research Centre (ESTEC), The Netherlands (2007-2008)
    • Postdoctoral Research Fellow
       
  • Aalto University (formerly Helsinki University of Technology), Laboratory of Space Technology, Finland (2001-2007)
    • Research Associate and Project Manager

Achievements

Awards & Recognitions

  • Senior Research Scientist | Remote sensing of the hydrologic cycle (2025)
  • NASA Award | NASA Group Achievement Awards (2019)
  • NASA Award | NASA Early Career Public Achievement Award (2017)
  • NASA Award | NASA Group Achievement Awards (2016)
  • NASA Award | NASA Group Achievement Awards (2013)

Publications

Selected peer-reviewed publications as the first author (out of 28)

  1. Colliander, A., Cosh, M. H., Bourgeau-Chavez, L., Kelly, V., Kraatz, S., Siqueira, P., Walker, V. A., Chen, X., Roy, A., Lakhankar, T., McDonald, K., Steiner, N., Kurum, M., Kim, S., Berg, A., et al. (2025). SMAP Validation Experiment 2019-2022 (SMAPVEX19-22): Field Campaign to Improve Soil Moisture and Vegetation Optical Depth Retrievals in Temperate Forests. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing (Vol. 18, pp. 10749–10771). https://doi.org/10.1109/jstars.2025.3553085
  2. Colliander, A., M. Mousavi, J.S. Kimball, J.Z. Miller, M. Burgin. (2023). Spatial and temporal differences in surface and subsurface meltwater distribution over Greenland ice sheet using multi-frequency passive microwave observations. Remote Sens. Environ., Vol. 295, 2023, 113705, https://doi.org/10.1016/j.rse.2023.113705.
  3. Colliander, A., Kerr, Y., Wigneron, J.-P., Al-Yaari, A., Rodriguez-Fernandez, N., Li, X., Chaubell, J., Richaume, P., Mialon, A., Asanuma, et al. (2023). Performance of SMOS Soil Moisture Products over Core Validation Sites. IEEE Geoscience and Remote Sensing Letters, Vol. 20, pp. 1-5, Art no. 2502805, https://doi.org/10.1109/lgrs.2023.3272878
  4. Colliander, A., M. Mousavi, S. Marshall, S. Samimi, J. Kimball, J. Miller, J. Johnson, M. Burgin. (2022). Ice Sheet Surface and Subsurface Melt Water Discrimination using Multi-frequency Microwave Radiometry. Geophysical Research Letters, 49, e2021GL096599. https://doi.org/10.1029/2021GL09659
  5. Colliander, A., R. H. Reichle, W. Crow, M. H. Cosh, F. Chen, N. Das, R. Bindlish, M. J. Chaubell, S. B. Kim, Q. Liu, et al. (2022). Validation of Soil Moisture Data Products from the NASA SMAP Mission. IEEE J. Sel. Topics Appl. Earth Obs. Remote Sens. Vol. 15, pp. 364-392, https://doi.org/10.1109/JSTARS.2021.3124743
  6. Colliander, A., Cosh, M. H., Kelly, V. R., Kraatz, S., Bourgeau‐Chavez, L., Siqueira, P., A. Roy, A.G. Konings, N. Holtzman, S. Misra, et al. (2020). SMAP Detects Soil Moisture under Temperate Forest Canopies. Geophysical Research Letters. Vol. 47. https://doi.org/10.1029/2020GL089697
  7. Colliander, A., Z. Yang, R. Mueller, A. Sandborn, R. Reichle, W. Crow, D. Entekhabi, and S. Yueh. (2019). Consistency between NASS Surveyed Soil Moisture Conditions and SMAP Soil Moisture Observations. Water Resources Research. Vo. 55, No. 9, pp. 7682-7693. https://doi.org/10.1029/2018WR02447
  8. Colliander, A., J.B. Fisher, G. Halverson, O. Merlin, S. Misra, R. Bindlish, T.J. Jackson, S. Yueh (2017). Spatial Downscaling of SMAP Soil Moisture using MODIS Land Surface Temperature and NDVI during SMAPVEX15. IEEE Geoscience and Remote Sensing Letters, Vol. 14, No. 11. https://doi.org/10.1109/LGRS.2017.2753203
  9. Colliander, A., M.H. Cosh, S. Misra, T.J. Jackson, W.T. Crow, S. Chan, R. Bindlish, C. Chae, C. Holifield Collins, S.H. Yueh. (2017). Validation and Scaling of Soil Moisture in a Semi-Arid Environment: SMAP Validation Experiment 2015 (SMAPVEX15). Remote Sensing of Environment, 196, 101-112. https://doi.org/10.1016/j.rse.2017.04.022
  10. Colliander, A., J.T. Jackson, R. Bindlish, S. Chan, S.B. Kim, M.H. Cosh, R.S. Dunbar, L. Dang, L. Pashaian, J. Asanuma, et al. (2017). Validation of SMAP surface soil moisture products with core validation sites. Rem. Sens. Env., Vol. 191, pp. 215-231. https://doi.org/10.1016/j.rse.2017.01.021
  11. Colliander, A., E.G. Njoku, T.J. Jackson, S. Chazanoff, H. McNairn, J. Powers, M.H. Cosh. (2016). Retrieving soil moisture for non-forested areas using PALS radiometer measurements in SMAPVEX12 field campaign. Remote Sens. Environ., Vol. 184, pp. 86-100, 2016. https://doi.org/10.1016/j.rse.2016.06.001
  12. Colliander, A., Jackson, T., McNairn, H., Chazanoff, S., Dinardo, S., Latham, B., O’Dwyer, I., Chun, W., Yueh, S., Njoku, E. (2015). Comparison of Airborne Passive and Active L-band System (PALS) Brightness Temperature Measurements to SMOS Observations during the SMAP Validation Experiment 2012 (SMAPVEX12). IEEE Geoscience Remote Sensing Letters, Vol. 12, No. 4, April 2015. https://doi.org/10.1109/LGRS.2014.2362889
  13. Colliander, A. (2012). Analysis of Coincident L-Band Radiometer and Radar Measurements With Respect to Soil Moisture and Vegetation Conditions. European Journal of Remote Sensing, vol. 45, pp. 111-120. https://doi.org/10.5721/EuJRS20124511
  14. Colliander, A., McDonald, K., Zimmermann, R., Linke, T., Schroeder, R., Kimball, J., Njoku, E. (2012). Application of QuikSCAT Backscatter to SMAP Validation Planning: Freeze/Thaw State over ALECTRA Sites in Alaska from 2000 to 2007”, IEEE Transactions on Geoscience and Remote Sensing, vol. 50, no. 2. https://doi.org/10.1109/TGRS.2011.2174368
  15. Colliander, A., Narhi, T., de Maagt, P. (2010). Modeling and Analysis of Polarimetric Synthetic Aperture Interferometric Radiometers Using Noise Waves. IEEE Transactions on Geoscience and Remote Sensing, vol. 48, no. 9. https://doi.org/10.1109/TGRS.2010.2047261
  16. Colliander, A., Corbella, I., Torres, F. (2009). Correlation Denormalization in Interferometric or Polarimetric Radiometers: A Unified Approach. IEEE Transactions on Geoscience and Remote Sensing, vol. 47, no. 2. https://doi.org/10.1109/TGRS.2008.2003247
  17. Colliander, A., Ylä-Oijala, P. (2007). Electromagnetic Scattering from Rough Surface Using Single Integral Equation and Adaptive Integral Method. IEEE Transactions on Antennas and Propagation, vol. 55, no. 12. https://doi.org/10.1109/TAP.2007.910337
  18. Colliander, A., Lahtinen, J., Tauriainen, S., Pihlflyckt, J., Lemmetyinen, J., Hallikainen, M. (2007). Sensitivity of Airborne 36.5-GHz Polarimetric Radiometer's Wind-Speed Measurement to Incidence Angle. IEEE Transactions on Geoscience and Remote Sensing, vol. 45, no. 7. https://doi.org/10.1109/TGRS.2007.894936
  19. Colliander, A., Kettunen, J., Hallikainen, M. T. (2006). Calibration of End-to-end Phase Imbalance of Polarimetric Radiometers. IEEE Transactions on Geoscience and Remote Sensing, vol. 44, no. 10, pp. 2635-2641. https://doi.org/10.1109/TGRS.2006.877759
  20. Colliander, A., Tauriainen, S., Auer, T., Kainulainen, J., Uusitalo, J., Toikka, M., Hallikainen, M. (2005). MIRAS Reference Radiometer: A Fully Polarimetric Noise Injection Radiometer. IEEE Transactions on Geoscience and Remote Sensing, vol. 43, no. 5, pp. 1135-1143. https://doi.org/10.1109/TGRS.2004.840667
     

Selected peer-reviewed publications as a co-author (out of 115)

  1. Akins, A. B., Tanner, A. B., Colliander, A., Schlegel, N.-J., Boudad, K., Yanovsky, I., Brown, S. T., & Misra, S. (2025). A Sparse Synthetic Aperture Radiometer Constellation Concept for Remote Sensing of Antarctic Ice Sheet Temperature. IEEE Transactions on Geoscience and Remote Sensing (Vol. 63, pp. 1–21). https://doi.org/10.1109/tgrs.2025.3534466Walker, C., J. Millstein, B. Miles, S. Cook, A. Fraser, A. Colliander, S. Misra, L. Trusel, S. Adusumilli, C. Roberts, and H.A. Fricker. (2024). Multi-decadal Collapse of East Antarctica’s Conger-Glenzer Ice Shelf. Nature Geoscience. Accepted.
  2. Ayres, E., Reichle, R. H., Colliander, A., Cosh, M. H., & Smith, L. (2024). Validation of Remotely Sensed and Modeled Soil Moisture at Forested and Unforested NEON Sites. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing (pp. 1–19). https://doi.org/10.1109/jstars.2024.3430928
  3. Kim, Y., Kimball, J. S., Parazoo, N., Xu, X., Colliander, A., Reichle, R., Xiao, J., & Li, X. (2024). Diagnosing Spring Onset Across the North American Arctic‐Boreal Region Using Complementary Satellite Environmental Data Records. Journal of Geophysical Research: Biogeosciences (Vol. 129, Issue 8). https://doi.org/10.1029/2023jg007977
  4. Jeong, J., L. Tsang, A. Colliander, S. Yueh, "Full-Wave Electromagnetic Simulations of Forests at L-Band by Using Fast Hybrid Method," Progress In Electromagnetics Research, Vol. 178, 111-127, 2023. doi:10.2528/PIER23082204
  5. Rodriguez-Alvarez, N., Munoz-Martin, J.F., Bosch-Lluis, X. Oudrhiri, K., Entekhabi, D., Colliander, A. The first polarimetric GNSS-Reflectometer instrument in space improves the SMAP mission’s sensitivity over densely vegetated areas. Sci Rep 13, 3722 (2023). https://doi.org/10.1038/s41598-023-30805-7
  6. Crow, W. T., F. Chen, A. Colliander. (2022). Benchmarking downscaled satellite-based soil moisture products using sparse, point-scale ground observations. Remote Sensing of Environment. Vol. 283, p. 113300. https://doi.org/10.1016/j.rse.2022.113300
  7. Gu, W., L. Tsang, A. Colliander, S. Yueh. (2022). Hybrid Method for Full-Wave Simulations of Forests at L-Band. IEEE Access, Vol. 10, pp. 105898-105909, https://doi.org/10.1109/ACCESS.2022.3211323.
  8. Thomas Ambadan, J., H.C. McRae, A. Colliander, E. Tetlock, W. Helgason, Z. Gedalof, A. Berg. (2022). Evaluation of SMAP Soil Moisture Retrieval Accuracy Over a Boreal Forest Region," IEEE Transactions on Geoscience and Remote Sensing, Early Access. https://doi.org/10.1109/TGRS.2022.3212934.
  9. Mousavi, S., A. Colliander, J.Z. Miller, J.S. Kimball. (2022). A Novel Approach to Map the Intensity of Surface Melting on the Antarctica Ice Sheet using SMAP L-Band Microwave Radiometry, IEEE J. Sel. Topics Appl. Earth Obs. Remote Sens. vol. 15, pp. 1724-1743, https://doi.org/10.1109/JSTARS.2022.3147430
  10. Crow, W. T., F. Chen, A. Colliander. (2022). Benchmarking downscaled satellite-based soil moisture products using sparse, point-scale ground observations. Remote Sensing of Environment. Vol. 283, p. 113300. https://doi.org/10.1016/j.rse.2022.113300
  11. Yueh, S., R. Shah, M. J. Chaubell, A. Hayashi, X. Xu, A. Colliander. (2022). A Semi-Empirical Modeling of Soil Moisture, Vegetation and Surface Roughness Impact on CYGNSS Reflectometry Data. IEEE Trans. Geosci. Remote Sensing, Accepted for publication. https://doi.org/10.1109/TGRS.2020.3035989
  12. Mousavi, S., A. Colliander, J.Z. Miller, D. Entekhabi, J.T. Johnson, C.A. Shuman, J.S. Kimball, Z.R. Courville. (2021). Evaluation of Surface Melt on the Greenland Ice Sheet using SMAP L-Band Microwave Radiometry, IEEE J. Sel. Topics Appl. Earth Obs. Remote Sens. vol. 14, pp. 11439-11449, https://doi.org/10.1109/JSTARS.2021.3124229.
  13. van der Velde, R., Colliander, A., Pezij, M., Benninga, H.-J. F., Bindlish, R., Chan, S. K., Jackson, T. J., Hendriks, D. M. D., Augustijn, D. C. M., and Su, Z. (2021). Validation of SMAP L2 passive-only soil moisture products using upscaled in situ measurements collected in Twente, the Netherlands, Hydrol. Earth Syst. Sci., 25, 473–495, https://doi.org/10.5194/hess-25-473-2021, 2021.
  14. Holtzman, N., L.D.L. Anderegg, S. Kraatz, A. Mavrovic, O. Sonnentag, C. Pappas, M.H. Cosh, A. Langlois, T. Lakhankar, D. Tesser, N. Steiner, A. Colliander, A. Roy, A.G. Konings. (2021). L-band vegetation optical depth as an indicator of plant water potential in a temperate deciduous forest stand. Biogeosciences. Under Review. https://doi.org/10.5194/bg-2020-373
  15. Gruber, A., G. De Lannoy, C. Albergel, A. Al-Yaari, L. Brocca, J.-C. Calvet, A. Colliander, M. Cosh, W. Crow, W. Dorigo, et al. (2020). Validation Practices for Satellite Soil Moisture Retrievals: What Are (the) Errors? Remote Sens. Environ., Vol. 244. https://doi.org/10.1016/j.rse.2020.111806
  16. Reichle, R., Q. Liu, R.D. Koster, W. Crow, G.J.M. De Lannoy, J.S. Kimball, J.V. Ardizzone, D. Bosch, A. Colliander, M.H. Cosh, J. Kolassa, S.P. Mahanama, J. Prueger, P. Starks, J.P. Walker. (2019). Version 4 of the SMAP Level‐4 Soil Moisture Algorithm and Data Product. J. Adv. Modeling Earth Systems, Vol. 11, No. 10, pp. 3106-3130.
  17. Chen, F., W.T. Crow, R. Bindlish, A. Colliander, M.S. Burgin, J. Asanuma, K. Aida. (2018). Global-Scale Evaluation of SMAP, SMOS and ASCAT Soil Moisture Products using Triple Collocation. Remote Sensing of Environment, Vol. 214, pp. 1-13. https://doi.org/10.1016/j.rse.2018.05.008
  18. Chan, S.K.,  R. Bindlish, P. O'Neill, T. Jackson, E. Njoku, S. Dunbar, J. Chaubell, J. Piepmeier, S. Yueh, D. Entekhabi, A. Colliander, et al. (2018). Development and Assessment of the SMAP Enhanced Passive Soil Moisture Product. Remote Sensing of Environment, Vol. 204, pp. 931-941. https://doi.org/10.1016/j.rse.2017.08.025
  19. Jones, L.A., J.S. Kimball, R.H. Re,ichle, N. Madani, J. Glassy, J.V. Ardizzone, A. Colliander, J. Cleverly, A.R. Desai, D. Eamus, E.S. Euskirchen, L. Hutley, C. Macfarlane, R.L. Scott, “The SMAP Level 4 Carbon Product for Monitoring Ecosystem Land-Atmosphere CO2 Exchange,” IEEE Trasn. Geosci. Remote Sens., Vol. 55, No. 11, 2017.