ASSIST II Atmospheric Sounder
The ASSIST II (Atmospheric Sounder Spectrometer for Infrared Spectral Technology) is a field-deployable Fourier Transform infrared sounder representing the latest advancement in ground-based atmospheric sounding. Covering a wide spectral bandwidth of 3 – 19 µm across the MWIR and LWIR ranges, the ASSIST II delivers high spectral resolution down to 1 cm⁻¹ and generates atmospheric temperature and moisture profiles in near real time — every 2 minutes at finest resolution. Its rugged, compact enclosure is designed for 24/7 unattended operation on ground or sea platforms, with 100% remote controllability via network-centered architecture and the integrated Edgar software suite. Dual integrated high-emissivity blackbodies provide automatic self-calibrating radiometric calibration, ensuring outstanding accuracy and instrument-to-instrument reproducibility with no manual intervention required.
| Key Features |
|---|
| • High spectral resolution — down to 1 cm⁻¹; user-selectable in 8 steps (1, 2, 4, 8, 16, 32, 64, 128 cm⁻¹) |
| • Wide spectral bandwidth — covers the full MWIR and LWIR ranges (3 – 19 µm; optional 2 – 25 µm) |
| • Near real-time atmospheric profiling — generates temperature and moisture profiles every 2 minutes autonomously |
| • Self-calibrating radiometric accuracy — dual integrated high-emissivity blackbodies (emissivity >0.9998) with automatic calibration sequences |
| • True 24/7 unattended operation — works out of the box; integrated Edgar software handles all data acquisition, processing, and output autonomously |
| • 100% remotely controllable — network-centered architecture with extensive remote monitoring for maintenance from anywhere in the world |
| • Measures temperature, water vapor, O₃, CO, CO₂, CH₄, and NOₓ vs. altitude — produces atmospheric parameter profiles directly, not just spectra |
| • Rugged field-deployable design — compact enclosure rated for –30 °C to +40 °C; adaptable to ground and sea platforms |
System Specifications
| ASSIST II Specifications | |
|---|---|
| Detector & Spectral | |
| Detector Type | HgCdTe (MCT) and InSb detectors |
| Detector Format | Single-pixel |
| Spectral Range | 3 – 19 µm (optional extended range: 2 – 25 µm) |
| Spectral Resolution | 1, 2, 4, 8, 16, 32, 64, 128 cm⁻¹ (user-selectable) |
| Field of View (FOV) | 45 mrad |
| Typical NESR |
2.5 nW/sr/cm²/cm⁻¹ @ 1,300 cm⁻¹ 0.25 nW/sr/cm²/cm⁻¹ @ 2,000 cm⁻¹ (at 16 cm⁻¹ spectral resolution, 1s observation time) |
| Measurement Performance | |
| Measurement Rate | 1 spectra/s (at finest spectral resolution) |
| Atmospheric Profile Rate | 0.5 profile/minute (at finest spectral resolution) |
| Measured Parameters | Temperature, water vapor, O₃, CO, CO₂, CH₄, NOₓ vs. altitude |
| Integrated Calibration Unit | |
| Blackbody Configuration | 2 permanently mounted high-emissivity blackbodies; automatically selected per calibration sequence |
| Effective Emissivity | >0.9998 |
| Temperature Range | Ambient to 70.00 °C |
| Temperature Stability | 0.005 °C over 120 seconds |
| Temperature Knowledge | ±0.1 K absolute |
| Radiance Uncertainty | <±0.005 K |
| Mechanical & Environmental | |
| Instrument Dimensions | 90 × 79 × 50 cm (L × W × H) |
| Environmental Enclosure Dimensions | 140 × 102 × 163 cm (L × W × H) |
| Instrument Weight | 80 kg |
| Weight (with Enclosure) | 195 kg |
| Power Consumption |
<300 W (instrument only) <675 W (with enclosure, AC on) <300 W (with enclosure, AC off) |
| Operating Temp. | –30 °C to +40 °C (with environmental enclosure) |
| Communication Interface | Ethernet; USB, LVDS, and Camera Link for additional user devices |
