Satellite Technology
Get to know Hydrosat's on-orbit sensors.
VanZyl Constellation
VanZyl-1 (VZ-1) and VanZyl-2 (VZ-2) are Hydrosat's first two satellites. Launched in August 2024 (VZ-1) and June 2025 (VZ-2), the VanZyl satellites pave the way for our forthcoming constellation that will redefine space-based thermal infrared remote sensing by enabling daily continuous monitoring of any location on Earth.
Both VZ-1 and VZ-2 host two imaging payloads: Hydrosat’s first-generation, proprietary longwave infrared imager (LIRI) along with its visible and near-infrared imager (VIRI).
Spectral Bands
The LIRI sensor acquires thermal infrared imagery at wavelengths between 10.6 and 12.51 micrometers, similar to Landsat TIRS; VIRI has a total of 7 spectral bands ranging from 458 to 900 nanometers.
Blue
458-523 nm
Green
543-578 nm
Red
650-680 nm
Red Edge 1
698-713 nm
Red Edge 2
733-748 nm
Red Edge 3
773-793 nm
Near-Infrared (NIR)
785-900 nm
Longwave Infrared 1 (LWIR 1)
10.6-11.19 ÎĽm
Longwave Infrared 2 (LWIR 2)
11.5-12.51 ÎĽm
Other Specifications
VZ-1 and VZ-2 operate in low Earth orbit, collecting imagery at approximately the same local time each orbit. VZ-1's overpass time aligns approximately with that of Landsat, while VZ-2's is similar to VIIRS.
Sun-synchronous
500-600 km
10:30 AM (VZ-1) 1:30 PM (VZ-2)
10:30 PM (VZ-1) 1:30 AM (VZ-2)
70 km