OUR SPACECRAFT INSTRUMENTS

---

GNSS-RO is a satellite remote sensing technique where GNSS (e.g. GPS) measurements received by low-Earth orbiting satellites profile the Earth's atmosphere and ionosphere with high vertical resolution and global coverage. The high accuracy and vertical resolution of GNSS-RO data make them ideally suited to study weather forecasting, climate monitoring and model verification, and space weather and ionospheric research. In addition to tracking L1 C/A, L2C, L2 P(Y) (semi-codeless) for PNT, it also provides ionospheric line integrated density measurements and scintillation inducing small-scale density structures.

Atmospheric radio occultation relies on the detection of a change in a radio signal as it passes through a planet's atmosphere, i.e. as it is occulted by the atmosphere. When electromagnetic radiation passes through the atmosphere, it is refracted (or bent). The magnitude of the refraction depends on the gradient of refractivity normal to the path, which in turn depends on the density gradient. The effect is most pronounced when the radiation traverses a long atmospheric limb path. At radio frequencies the amount of bending cannot be measured directly; instead, the bending can be calculated using the Doppler shift of the signal given the geometry of the emitter and receiver.

Energetic charged particles, originating in magnetic activity in the Sun and in the solar wind, is a major space weather hazard. Depending on the energy of the particle radiation, it can cause surface or internal charging in satellites, degrade functional surfaces and devices, and induce single-event effects, possibly leading to anomalies or even failure of satellites. Our compact energetic particle instrument uses a telescope design consisting of three silicon detectors and one scintillation detector. It provides measurements of 0.4–8 MeV electrons and 10–200 MeV protons with a temporal resolution of 1–63 seconds per spectrum, making it well suited for monitoring both radiation belt and solar energetic particles. The differential spectra are measured in 12 channels for electrons and 16 for protons. The instrument includes a miniature dosimeter measuring the dose deposited in its sensor by ionizing radiation in the space environment. The sensor is covered by housing that is representative of a spacecraft structural shielding. Thus, the dose absorbed in the sensor corresponds to the dose absorbed by the electronics. The instrument provides the total dose rate and deposited energy spectra in 128 energy channels with a nominal resolution of 15 seconds. 

A solar X-ray spectrometer is used for measuring and characterizing solar flares, which are known to cause a variety of space weather phenomena and are related to solar energetic particle (SEP) events, and may be accompanied by coronal mass ejections (CME). These affect the functionality of electronic devices and technological systems both in space and on ground, and can, in the worst case, shut off satellites, cause blackouts of long range radio frequency communication, and destroy electric power grids. Our instrument measures differential X-ray flux in the energy range of 1–30 keV. Its dynamic range is 2×10-7–1×10-3 Wm-2 (B2–X10 in solar flare classes), making it well suited for solar flare activity observations. It provides differential energy spectra in several channels with a time resolution of 1–63 seconds per spectrum, as well as an integral count rate over the energy range. The instrument also includes a single-detector that measures low energy electrons with a specified energy range of 10–50 keV and a projected energy range of 3.5–100 keV. It provides a comprehensive in situ measurement of mid- and high-energy auroral electrons in Low Earth Orbit. It provides energy spectra in 12 differential channels with a time resolution of 0.1–10 seconds per spectrum. It is designed for operation in quiet and stormy conditions with a projected dynamic flux range of 104–109 cm-2 s-1 sr-1 keV -1, depending on the time resolution.

An SST camera is used to monitor the satellite’s environment and/or to monitor the satellite itself, and can be used to film the deployment of the different parts of the satellites, the separations, and to assess any satellite anomalies. It can also detect and observe the approach of a satellite. Space Situational Awareness (SSA) refers to the knowledge of the space environment, including location and function of space objects and space weather phenomena. This includes Space Surveillance and Tracking (SST) of man-made objects and Space WEather (SWE) monitoring and forecasting.

A tri-frequency beacon’s main science goal is to study the natural formation of bubbles in Earth's electrically-charged upper atmosphere, called the ionosphere, and measure ionospheric density. Factors from near Earth's surface, like weather, and changing conditions in space called space weather can influence the winds and the electric and magnetic fields to push around the gases in the ionosphere making it hard to predict what its state will be at any given time.  Ground station receivers measure where, how and when the signals are distorted by these atmospheric bubbles as they evolve in real-time.

A Langmuir probe is an instrument to provide high cadence in-situ absolute ion density biased in the ion saturation region. It measures RAM plasma current that is directly proportional to ion density, collection area, and spacecraft velocity. It is also capable of measuring magnetic fields with sensitivity down to units of nT. These measurements, when coupled with GNSS-RO, provide both ionosphere and thermosphere measurements related to the Equatorial Ionization Anomaly (EIA) and the Equatorial Temperature and Wind Anomaly (ETWA). The EIA and ETWA are two of the dominant ionosphere/thermosphere interactions on the low-latitude duskside.