The TRISHNA Mission: A New Era of High-Resolution Thermal Infrared Earth Observation for Land Surface Monitoring

Gamet, Philippe; Bhattacharya, Bimal K.; Roujean, Jean-Louis; Boulet, Gilles; Salcedo, Corinne; Olioso, Albert; Mallick, Kanishka; Weiss, Marie; Sarrazin, Emmanuelle; Autret, Emmanuelle; Roupioz, Laure; Sobrino, José Antonio; Merlin, Olivier; Picard, Ghislain; Vidal, Thomas H. G.; Irvine, Mark; Nigam, Rahul; Pandya, Mehul; Gascoin, Simon; Marcq, Sébastien; Mishra, Manoj K.; Delogu, Emilie; Rivalland, Vincent; Etchanchu, Jordi; Raynaud, Jean-Louis; Sarkar, Meenakshi; Gangwar, Rishi K.; Singh, Sushil K.; Binet, Renaud; Arioli, Sara; Yésou, Hervé; Dadou, Isabelle; Kouraev, Alexei; Michel, Julien; Coudert, Benoit; Mwangi, Samuel; Farhani, Nesrine; Das, Ayan; Saux-Picart, Stéphane; Tormos, Thierry; Piollé, Jean-François; Verpoorter, Charles; Rodler, Auline; Leon Tavares, Jonathan; Adams, Jennifer; Sahadevan, Anand S.; Santhi Sree, Besavaraju; Vedantam, Manikumar; Adlakha, Dheeraj; Buffet, Laurence; Naegeli, Kathrin; Barat, Itziar; Demarty, Jerome; Hagolle, Olivier; Maisongrande, Philippe

doi:10.5194/egusphere-2026-4492

Preprints

https://doi.org/10.5194/egusphere-2026-4492

Preprints

31 Jul 2026

| 31 Jul 2026

Status: this preprint is open for discussion and under review for Earth Observation (EO).

The TRISHNA Mission: A New Era of High-Resolution Thermal Infrared Earth Observation for Land Surface Monitoring

Philippe Gamet, Bimal K. Bhattacharya, Jean-Louis Roujean, Gilles Boulet, Corinne Salcedo, Albert Olioso, Kanishka Mallick, Marie Weiss, Emmanuelle Sarrazin, Emmanuelle Autret, Laure Roupioz, José Antonio Sobrino, Olivier Merlin, Ghislain Picard, Thomas H. G. Vidal, Mark Irvine, Rahul Nigam, Mehul Pandya, Simon Gascoin, Sébastien Marcq, Manoj K. Mishra, Emilie Delogu, Vincent Rivalland, Jordi Etchanchu, Jean-Louis Raynaud, Meenakshi Sarkar, Rishi K. Gangwar, Sushil K. Singh, Renaud Binet, Sara Arioli, Hervé Yésou, Isabelle Dadou, Alexei Kouraev, Julien Michel, Benoit Coudert, Samuel Mwangi, Nesrine Farhani, Ayan Das, Stéphane Saux-Picart, Thierry Tormos, Jean-François Piollé, Charles Verpoorter, Auline Rodler, Jonathan Leon Tavares, Jennifer Adams, Anand S. Sahadevan, Besavaraju Santhi Sree, Manikumar Vedantam, Dheeraj Adlakha, Laurence Buffet, Kathrin Naegeli, Itziar Barat, Jerome Demarty, Olivier Hagolle, and Philippe Maisongrande

Abstract. Thermal infrared (TIR) satellite remote sensing is essential for monitoring land surface temperature (LST) and surface energy fluxes, supporting applications in hydrology, agriculture, climate, and urban climate. Existing TIR missions—such as LANDSAT, ASTER, ECOSTRESS, and Sentinel-3 SLSTR—offer complementary capabilities but remain constrained by trade-offs between spatial resolution, revisit frequency, and radiometric accuracy, limiting their ability to capture rapidly evolving surface processes at field to regional scales.

The TRISHNA (Thermal Infrared Satellite for High-Resolution Natural Resource Assessment) mission, expected in 2027, addresses this gap by providing 60 m TIR imagery over a ~1000 km swath with sub-weekly revisit, enabling systematic monitoring of surface energy processes in natural and managed ecosystems. Its integrated design —including orbit configuration, spectral channels (VNIR, SWIR, TIR), viewing geometry, and calibration strategy— supports accurate retrievals of evapotranspiration, vegetation water stress, and surface temperature dynamics. Synergies with upcoming missions such as ESA’s Land Surface Temperature Mission (LSTM) and NASA’s EAGLE mission (Explorer for Artemis Geology Lunar and Earth) will enhance temporal coverage, cross-calibration, and long-term data continuity.

How to cite. Gamet, P., Bhattacharya, B. K., Roujean, J.-L., Boulet, G., Salcedo, C., Olioso, A., Mallick, K., Weiss, M., Sarrazin, E., Autret, E., Roupioz, L., Sobrino, J. A., Merlin, O., Picard, G., Vidal, T. H. G., Irvine, M., Nigam, R., Pandya, M., Gascoin, S., Marcq, S., Mishra, M. K., Delogu, E., Rivalland, V., Etchanchu, J., Raynaud, J.-L., Sarkar, M., Gangwar, R. K., Singh, S. K., Binet, R., Arioli, S., Yésou, H., Dadou, I., Kouraev, A., Michel, J., Coudert, B., Mwangi, S., Farhani, N., Das, A., Saux-Picart, S., Tormos, T., Piollé, J.-F., Verpoorter, C., Rodler, A., Leon Tavares, J., Adams, J., Sahadevan, A. S., Santhi Sree, B., Vedantam, M., Adlakha, D., Buffet, L., Naegeli, K., Barat, I., Demarty, J., Hagolle, O., and Maisongrande, P.: The TRISHNA Mission: A New Era of High-Resolution Thermal Infrared Earth Observation for Land Surface Monitoring, EGUsphere [preprint], https://doi.org/10.5194/egusphere-2026-4492, 2026.

Received: 25 Jul 2026 – Discussion started: 31 Jul 2026

Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this paper. While Copernicus Publications makes every effort to include appropriate place names, the final responsibility lies with the authors. Views expressed in the text are those of the authors and do not necessarily reflect the views of the publisher.

Download & links

Status: open (until 11 Sep 2026)

Post a comment Subscribe to comment alert

RC1: 'Comment on egusphere-2026-4492', Anonymous Referee #1, 27 Aug 2026 reply

The TRISHNA Mission: A New Era of High-Resolution Thermal Infrared Earth Observation for Land Surface Monitoring
General comments: This paper provides a comprehensive overview of the TRISHNA mission, describing the science applications, the mission design, system definition, products and calibration/validation strategy and synergies with other missions. It will provide a useful reference paper for users. Most of my comments are minor in nature and reflect a knowledge bias on my part related to urban environments. I provide separately an annotated copy of the pdf with typographical/wording suggestions.
Specific Comments
It would be useful to include a table of abbreviations/acronyms
L 59 Suggest adding ‘surface’ to allow the more specific "surface urban heat island intensity" since UHI is a more generic term and air and surface UHI are distinctly different.
L 106-108 I think there may be some Chinese satellite-based sensors that may also be included? SDGSAT-1?
L160-162 Consider adding forest fire risk to the applications?
L185 probably should define blue and green water
L 227 Consider adding a reference to Hall et al. 2024 DOI: 10.1002/qj.4669 for use of LST in evaluating urban models.
L 236 There is some additional more recent urban thermal anisotropy work that may be useful to reference, e.g. see work by Wenfeng Zhan and collaborators. One option may be Du et al. 2023 10.1016/j.scib.2023.06.032
Section 2.6 I wonder if this might better come before the various applications?
L 322-325 This seems to partially repeat information – given the length of the paper I would recommend trying to shorten where opportunities arise.
Figure 2 is not in colour as implied by the caption.
L 435 Add some comment re urban anisotropy here, which can be larger.
L 445-451 There is also urban work related, e.g. see my earlier comment.
L 463 In urban areas the observations opposite the hotspot may also be significantly influenced by anisotropy. Perhaps a flag on surface structure (e.g. LCZ related?) to warn of potential anisotropy in more densely built urban regions?
L 478 Use SUHI in place of UHI here and elsewhere.
L 542 50 m is closer to the scale of the dominant surface structure variability in urban areas that controls LST variation but there is still a lot of urban structure/surface characteristic variability at smaller scales. One reference here that addresses this is Schmid & Oke 1997.

Schmid, H.P. and Oke, T.R., 1992. Scaling North American urban climates by lines, lanes, and rows. The Guildford Press: New York.
L 449 There seems a bias here to mid-latitude type climates that if not addressed later perhaps should be acknowledged.
L 561-562 Just a comment that this is also important for land surface studies since dT/dt is strong near sunset.
L 668 Should this be "with transmittance lowering overall with increasing atmospheric water"? (However Fig 9 doesn't show results for different amounts of atmospheric water).
Figure 10 Given that urban areas are one anticipated (and important) target of the mission, it may be good to include some representation of urban emissivity and associated challenges (e.g. not just material variability but emissivity effects due to surface geometry, specular effects etc) within this section.
L 722 Define FHWM and consider a list of abbreviations/acronyms.
L 983 Is there explicit processing for thermal anisotropy? If so, what approaches are applied?
L 1064 This may be more of a wording issue but it wasn’t clear to me as I read the paper if this is also a modular approach or an inversion approach?
L 1181 There may be other potential evaluation sites - e.g. FluxNet sites?

Reply

Citation: https://doi.org/10.5194/egusphere-2026-4492-RC1

Viewed

Total article views: 395 (including HTML, PDF, and XML)

HTML	PDF	XML	Total	BibTeX	EndNote
273	105	17	395	20	22

HTML: 273
PDF: 105
XML: 17
Total: 395
BibTeX: 20
EndNote: 22

Views and downloads (calculated since 31 Jul 2026)

Month	HTML	PDF	XML	Total
Jul 2026	35	8	3	46
Aug 2026	198	73	9	280
Sep 2026	40	24	5	69

Cumulative views and downloads (calculated since 31 Jul 2026)

Month	HTML	PDF	XML	Total
Jul 2026	35	8	3	46
Aug 2026	198	73	9	280
Sep 2026	40	24	5	69

Viewed (geographical distribution)

Total article views: 253 (including HTML, PDF, and XML) Thereof 253 with geography defined and 0 with unknown origin.

Country	#	Views	%

Latest update: 09 Sep 2026

Short summary

This paper highlights how the upcoming TRISHNA satellite mission (launching 2027) will transform Earth observation by providing high-resolution (60 m) thermal infrared imagery with sub-weekly revisits. It details the mission's design and its synergies with other future missions to significantly improve the monitoring of global surface temperature and its dynamics, water stress, and ecosystem energy processes.


Total:	0
HTML:	0
PDF:	0
XML:	0