August 28, 2017 - China Launches Satellite for Climate Monitoring

The satellite you're thinking of from that era has since evolved into something far more advanced. China's atmospheric monitoring program didn't stop there—it's now operating Daqi-2, launched April 17, 2025, a dedicated greenhouse gas satellite tracking CO2, CH4, CO, and N2O with remarkable precision. Built on SAST's largest platform, it works alongside Daqi-1 to create continuous global atmospheric profiles. There's much more to this story if you keep going.

Key Takeaways

China's Daqi-1 satellite launched April 15, 2022, from Taiyuan Satellite Launch Center, dedicated to atmospheric and climate monitoring missions.
Daqi-2 followed on April 17, 2025, aboard a Long March 4C rocket, focusing on greenhouse gas tracking globally.
The satellites monitor CO2, CH4, CO, and N2O, achieving CO2 precision of one part per million.
Both satellites operate in coordinated sun-synchronous orbits near 700–705 km, providing complementary aerosol and greenhouse gas observations through 2030.
Developed by SAST on the SAST-5000B bus, the program succeeds the Gaofen-5 series with an 8-year design lifetime.

What Is the Daqi-2 Greenhouse Gas Satellite?

China's Daqi-2 is a high-precision greenhouse gas monitoring satellite launched April 17, 2025, aboard a Long March 4C rocket from the Jiuquan Satellite Launch Center. Developed by SAST and operated by CNSA, it's the second-generation Atmospheric Environment Monitoring Satellite, succeeding the Gaofen-5 series.

You can think of Daqi-2 as China's dedicated greenhouse mapping platform, tracking CO2, CH4, CO, and N2O across the globe. It orbits at roughly 705 km in a sun-synchronous path, delivering spatial resolution up to 50 meters and swath widths reaching 2,400 km.

Through orbital coordination with Daqi-1, both satellites work together until 2030, creating complementary atmospheric profiles. While Daqi-1 focuses on aerosols, Daqi-2 emphasizes specialized greenhouse gas spectrometers, strengthening long-term climate and emissions research. Its onboard instruments include an Atmospheric Detection Lidar for active atmospheric profiling alongside passive sensors covering infrared and ultraviolet spectral ranges.

The satellite is built on the SAST-5000B bus, SAST's largest and most advanced satellite platform, which provides up to 20 kW of power and supports a design lifetime of 8 years. This kind of long-term atmospheric monitoring mirrors the goals of ground-based efforts like Canada's Eureka Weather Station, established in 1947 on Ellesmere Island to track northern climate conditions over extended periods.

What Instruments Does Daqi-2 Carry?

Daqi-2 carries five instruments that work together to monitor greenhouse gases, aerosols, and atmospheric composition. You'll find cutting-edge tools designed for precision atmospheric observation, including advanced aerosol profiling and spectral imaging capabilities.

Here's what makes Daqi-2's payload remarkable:

ACDL performs aerosol profiling at 532 nm and 1064 nm, separating molecular and particulate backscatter with 50 m land resolution
GAS-2 measures CO2, CH4, CO, and N2O across four NIR/SWIR bands using spectral imaging
Cloud and Aerosol Imager monitors cloud properties with hyperspectral capabilities
Wide-Swath Hyperspectral Greenhouse Gas Monitor delivers broad global coverage for atmospheric pollutants

The fifth instrument, the Infrared Hyperspectral Atmospheric Composition Detector, targets trace gases and aerosols in the infrared spectrum, completing Daqi-2's comprehensive monitoring suite. The satellite operates on the SAST-5000B bus platform, providing the structural and power foundation that supports this advanced instrument suite in orbit. Daqi-2 was launched into sun-synchronous orbit aboard a Long March 4C rocket from the Jiuquan Satellite Launch Center on April 17, 2026.

How Does Daqi-2 Track Greenhouse Gases and Air Pollution?

Orbiting at 700 kilometers in a sun-synchronous orbit, this satellite combines active and passive monitoring techniques to track greenhouse gases and air pollution with remarkable precision.

You'll find that its laser lidar system vertically profiles aerosols and clouds globally, while passive instruments capture optical and heat-based atmospheric signatures simultaneously.

For greenhouse gas detection, Daqi-2 achieves one part per million precision for CO2 and eight parts per billion accuracy for methane.

It also tracks carbon monoxide, nitrous oxide, and UV-reflective compounds affecting air quality.

When monitoring urban plumes, its 2,400-kilometer swath width ensures expansive coverage, while coordinated operation with Daqi-1 delivers complete global data.

This integrated active-passive approach represents the first system of its kind for comprehensive atmospheric composition monitoring. Developed by the Shanghai Academy of Spaceflight Technology, Daqi-2 carries five onboard instruments spanning lidar, cloud and aerosol imaging, and hyperspectral detection across wide-swath, infrared, and ultraviolet ranges.

The vast volumes of atmospheric data Daqi-2 generates can be stored and processed using scalable object storage solutions like Amazon S3, which provides durable, API-accessible storage with no upfront hardware costs.

How Does Daqi-2 Build on China's Daqi-1 Atmospheric Satellite?

Building on the active-passive monitoring capabilities just described, Daqi-2 doesn't operate in isolation—it's the direct successor to Daqi-1, which launched April 15, 2022, as part of China's second-generation Atmospheric Environment Monitoring Satellites (AEMS).

This mission continuity ensures China's atmospheric record never breaks. Daqi-1 lifted off aboard a Long March 4C rocket from the Taiyuan Satellite Launch Center.

Key instrument advances Daqi-2 delivers over Daqi-1 include:

GAS-2 spectrometer targeting CO2, CH4, CO, and N2O with precision Daqi-1 couldn't achieve
Retained ACDL lidar preserving proven aerosol profiling validated against CALIPSO
Shared SAST-5000B bus ensuring seamless operational compatibility
Networked observations combining both satellites for comprehensive global coverage

Together, they complete the AEMS pair, transforming fragmented snapshots into a continuous, irreplaceable climate dataset you can trust for decades. Daqi-1 was developed by the Shanghai Academy of Spaceflight Technology (SAST) of the China Aerospace Science and Technology Corporation, establishing the institutional foundation that made this two-satellite program possible.

Why Daqi-2's Active-Passive Monitoring Changes Atmospheric Science?

What makes Daqi-2 a genuine leap forward is its fusion of passive optical sensing with active lidar—two complementary approaches that together reveal what neither can capture alone.

Passive sensors rely on reflected sunlight to retrieve aerosol optical depth and trace gas concentrations, but they hit hard limits in darkness and deep cloud layers. That's where active lidar steps in, firing laser pulses for nighttime sensing and vertical profiling of pollutants that passive instruments simply can't reach. Much like how combining two lens powers into a single optical instrument transformed vision science, integrating passive and active sensing into one platform transforms what atmospheric observation can achieve.

You get a complete atmospheric picture—from surface-level PM2.5 to high-altitude CO2 columns—across day and night cycles. This integration reduces measurement uncertainty, strengthens pollution source identification, and supports long-range aerosol transport tracking. For atmospheric science, it's not an incremental upgrade; it's a fundamentally more capable way to observe Earth's atmosphere. Daqi-2 is specifically designed as a high-precision greenhouse gas observing satellite, targeting the measurement demands that broader atmospheric missions cannot fully address on their own.

Among the payloads contributing to this mission, the Polarization Cross-Fire Suite—formed by DPC-II and POSP together—delivers enhanced aerosol and cloud characterization through complementary polarization measurements spanning near-UV to short-wave infrared wavelengths.