GNOMES-3 GNSS radio-occultation satellite launched

Artist’s illustration of a GNOMES satellite. (Image: Blue Canyon)

A new GNSS radio-occultation (RO) satellite is now in orbit. The GNOMES-3 — GNSS Navigation and Occultation Measurement Satellite — flew aboard the SpaceX Falcon 9 Transporter-4 rideshare mission on April 1 and was launched into a 646-km circular sun-synchronous orbit. The payload was powered on and operating nominally within four days of launch.

The GNOMES-3 was manufactured for PlanetiQ by Blue Canyon Technologies LLC, a wholly owned subsidiary of Raytheon Technologies. Using refracted GNSS signals, PlanetiQ can determine the density and moisture content of the atmosphere to improve weather predictions, helping improve NOAA weather models.

The GNOMES-3 joins GNOME-2 on orbit and is expected to achieve highly accurate GNSS-RO measurements using the fourth-generation Pyxis-RO sensor. PlanetiQ plans to launch more Pyxis-RO atmospheric and ionospheric sounding spacecraft in 2023. In all, PlanetiQ plans for a fleet of 20 GNOMES by 2024.

The GNOMES-2, launched in June 2021 on SpaceX’s Transporter-2 mission, produces more than 3,200 soundings of the Earth’s atmosphere and 5,000 ionosphere soundings per day with a large-aperture RO antenna that tracks all four GNSS constellations: GPS, Galileo, GLONASS and BeiDou.

The soundings have sufficient signal-to-noise ratio to indicate the location of the planetary boundary layer, as well as detect super refraction at the boundary layer and near the Earth’s surface. The higher quality GNSS-RO soundings, along with the associated lower troposphere assimilation tools, will be used to produce more accurate weather forecasting and hurricane tracking, and aid in energy, transportation and agriculture industries as well as serve as a climate record with its SI-traceable data.