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Spire Stratos

Data from around our planet, derived from navigation signals.
Data from Ground to Space
The Spire Stratos sensor, which uses signals from global navigation satellites, gathers data about our atmosphere, ground, oceans, and magnetic field. 
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Atmosphere: GNSS Radio Occultation

GNSS-RO provides unique temperature, pressure, and moisture vertical soundings through the atmosphere, similar to a weather balloon. Rather than data being available only twice per day from specific sites, GNSS-RO utilizes Spire’s satellite constellation to collect soundings 24/7 on a global basis and over remote regions like the oceans and the poles. In addition to being an important input for weather forecasting, GNSS-RO is also a climate-quality measurement. 

Ionosphere: Total Electron Content
When the GNSS receiver on-board a Spire satellite is powered on, it continuously tracks multiple dual-frequency GNSS satellite signals simultaneously. These signals are primarily used for the purpose of precise orbit determination, which is necessary for neutral atmospheric radio occultation inversion. However, during post-processing, the TEC is computed for each signal “arc”, leaving Spire with one of the best ionospheric data sets in the world. 
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Coming Soon: GNSS - Reflectometry
Through a technique known as GNSS Reflectometry (GNSS-R), Spire satellites will estimate sea surface roughness (mean square slope), sea surface wind speed, sea surface heights (altimetry), and sea ice extent maps over oceanic regions. Over land surfaces,  they will deliver soil moisture estimates and flood inundation/wetlands extent maps. GNSS-R measurements from Spire's nanosatellites will afford better spatial sampling than traditional point measurements as well as faster temporal repeat times.
Ionospheric Scintillation Indices: S4 and SigmaPhi
Scintillation indices are indicators for ionospheric turbulence. They provide indicators for "space weather" in the upper atmosphere. For example, they may indicate ionospheric "storms" consisting of electron density gradients which could lead to loss-of-lock on GNSS receivers, jeopardizing a receiver's ability to provide robust and accurate Position, Navigation, and Timing (PNT). Continuous monitoring of scintillation indices is key for understanding GNSS link health, and is a first step toward predicting potential GNSS regional outages.
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Solar Eclipse + Ionosphere?
Solar Eclipse + Ionosphere? page image
As the sun sets, that process of ionization decreases until just a trickle of radiation remains for ionization. Most of the electrons and ions recombine to return to a non-charged state. That is, of course, unless there is a solar eclipse.
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