GB/T 41539-2022 in English

Construction of core standard specification system

Surface temperature products are key parameters for remote sensing quantitative observation. This standard establishes a full-chain technical framework from data production to application. According to the complexity and spatiotemporal characteristics of the products, a three-level system of L2/L3/L4 is set up. Level L2 is based on original resolution scene data production, such as a typical data set of 30-minute phase within the day; Level L3 forms cross-phase tile data through geometric correction; Level L4 innovatively introduces climate model grid (CMG) to achieve long-term series data fusion.

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Comparison of product classification systems

Level	Spatial and temporal characteristics	Resolution	Effective accuracy	Data architecture
L2 level	Instantaneous scene product	Original resolution (100m-1km)	±1.5K	Onboard autonomous product format
L3 level	Daily space-time tile	Standardized layering (100m-0.05°)	±1.0K	Space-ground integrated grid system
L4 level	Monthly/annual synthetic products	CMG climate grid unit	±2.0K	Long time series fusion model

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Key technical parameter requirements

The metadata elements must include UTC time stamp, tile spatial positioning code and quality identification secondary encoding. Products above L3 must use military-grade geographic grid correction technology, and the image geometric accuracy must meet the 1/4 pixel compensation specification. In the value range normalization storage requirements, the temperature scaling coefficient is limited to the 0.02K/bit interval to ensure that the national products are consistent and comparable.

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Quality evaluation and inspection indicators

The specification clearly requires the use of the three-point inspection method:

• Multi-source sensor cross-validation in vegetation-covered areas
• RTM theoretical calculation of all-weather surface targets
• Unified correction of the Beidou navigation system time reference

The misidentification reconstruction rate ≤ 0.01% is the mandatory qualification line, and the auxiliary data must include the ecosystem classification evidence chain covering all construction land.

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Industry application policy recommendations

The advanced demonstration system based on product solutions should focus on:

1. Establish a multi-granular carbon emission inversion and tracing model
2. Build a long-term mechanism product library for global change research
3. Develop an agricultural annuity output value calculation system for the district level

Promote the construction of a microwave-multispectral joint verification platform under the ISO/TC211 framework, and ultimately form a data output channel that complies with international mutual recognition rules.