Announcement of Observation Requests for
the Total Anthropogenic and Natural emissions mapping SpectrOmeter-3 (TANSO-3) onboard
the Global Observing SATellite for Greenhouse gases and Water cycle (GOSAT-GW)

June 6, 2025
Revision: July 27, 2026
National Institute for Environmental Studies

　We would like to announce observation requests for the Total Anthropogenic and Natural emissions mapping SpectrOmeter-3 (TANSO-3) onboard the Global Observing SATellite for Greenhouse gases and Water cycle (GOSAT-GW), which was launched on June 29, 2025.

　Observations from TANSO-3’s Focus Mode will be made based on observation requests. Please refer to the “Handling Policy of Observation Requests for the Total Anthropogenic and Natural emissions mapping SpectrOmeter-3 (TANSO-3) onboard the Global Observing SATellite for Greenhouse gases and Water cycle (GOSAT-GW)”（PDF, 0.1 MB） for details.

　The schedules for accepting observation requests and releasing products of TANSO-3 are as follows:

• - Observation requests have been started in November 2025.
• - The trial version of L1B products have been provided to users listed below.*
  * A non-disclosure agreement has concluded in advance with the National Institute for Environmental Studies (NIES).
• - L1B products were released to the public on July 23, 2026.
• - L2 products will be released to the public July 2027.

Refer to the URL below for the GOSAT-GW TANSO-3 Data Policy.
https://www.nies.go.jp/soc/en/documents/datapolicy/ ("Data Policy" on the Satellite Observation Center website)

Start of Accepting Applications for Authorized Users of GOSAT-GW TANSO-3 Products

The Global Environment Bureau of the Ministry of the Environment of Japan and the National Institute for Environmental Studies will begin accepting applications for Authorized Users regarding the use of observational data from the Total Anthropogenic and Natural emissions mapping SpectrOmeter-3 (TANSO-3) onboard the Global Observing SATellite for Greenhouse gases and Water cycle, GOSAT-GW (IBUKI GW).

There are two types of Authorized Users:

• Authorized User (No Observation Requests): This type of Authorized User is eligible to receive TANSO-3 products prior to their release to General Users.
• Authorized User (Observation Requests Available): This type of Authorized User is eligible to receive TANSO-3 products prior to their release to General Users and has the right to apply for observation requests.

For detailed explanations regarding TANSO-3 products and the handling policy for Focus Mode observations, please refer to the following documents:

• “TANSO-3 Data Policy” (Satellite Observation Center website)
• Handling Policy of Observation Requests for the Total Anthropogenic and Natural emissions mapping SpectrOmeter-3 (TANSO-3) onboard the Global Observing SATellite for Greenhouse gases and Water cycle (GOSAT-GW)” （PDF, 0.1 MB）

Those who wish to register as Authorized Users should inquire about the Authorized User application at the G3PA Support Desk (information provided below) and apply for registration.
Detailed application guidelines can be found in the

“Application Guidelines for Authorized Users of the GOSAT-GW TANSO-3 Product Archive” （PDF, 0.7 MB）

For users who have been approved as Authorized Users and granted Observation Request privileges, observation requests may be submitted for observations scheduled as early as five weeks in advance.

Requests may also be submitted for observations scheduled further ahead, such as two months in advance.

Please note that the allocation of observation opportunities available to all Authorized Users with Observation Request privileges is extremely limited. The total allocation is expected to be approximately 10 observation requests per three-day period (one revisit cycle; 44 orbits)(*). In comparison, the NIES GOSAT-GW Project conducts approximately 90 to 100 observations during the same three-day period.

* As of July 2026, eight organizations have been recognized as Authorized Users eligible to submit observation requests..

L1B products were released to the public on July 23, 2026, and L2 products will be released to the public in around July 2027.

Contact for Authorized User application:

G3PA Support Desk, GOSAT-GW Project
National Institute for Environmental Studies

Email: g3pa_desk*nies.go.jp (please replace * with @ when sending an email)

(Released on October 31, 2025)
(Revised on July 27, 2026)

The links to the product format descriptions*¹ and samples of the GOSAT-GW TANSO-3 Wide Mode L2 GHG Product and GOSAT-GW TANSO-3 Wide Mode L2 NO₂ Product (hereinafter referred to collectively as "L2 Products") are listed below.
These samples were generated for the interface verification of applications using L2 Products. The column-averaged concentrations stored in the L2 Product (GHG) samples are based on GOSAT L4B products for the same date in 2018. The column amount of tropospheric NO₂ and other parameters stored in the L2 Product (NO₂) samples are based on L3 (monthly average) products*² from the sensor (TROPOMI) onboard the European Sentinel-5p satellite for the same month in 2021. Additionally, invalid values are stored in many other parameters.

*1 The product format description used to generate the L2 Product (GHG) samples was Version A.
*2 ESA CCI+ NO₂ TROPOMI level-3 data (https://www.temis.nl/airpollution//no2col/cci-no2-tropomi.php external link)

• Level 2 (GHG) Product Format Descriptions (Version C, PDF, 1.1 MB)
• Sample Products (GHG) (May 1–3, 2026, ZIP, 71 MB)
• Level 2 (NO₂) Product Format Descriptions (Version C, PDF, 0.7 MB)
• Sample Products (NO₂) (May 1–3, 2026, ZIP, 73 MB)

(Released on October 24, 2025)