The International Telecommunication Union-Radiocommunication sector (ITU-R) has conducted frequency sharing studies between fixed services (FSs) using a high altitude platform station (HAPS) and fixed-satellite services (FSSs).
During the 2014 2015 Pāhoa crisis on the island of Hawai'i, we used a low-altitude unmanned aerial system (UAS) to quickly and repeatedly image the active front of a slowly advancing pāhoehoe lava flow.
We fit electron densities between 170 and 230 km in each Mariner 9 profile using an exponential dependence on altitude, then tested whether electron densities at higher altitudes were appreciably greater than those predicted by a simple upwards extension of the fit.
Suitable habitat was predicted in some areas above 1500 m in altitude, and because the species does not generally occur above this elevation (Ridgely and Greenfield 2001), we used a conservative maximum altitude of 2000 m a.s.l.l
Morel also used an iPhone that took altitude readings, and wore a smart bracelet running a stress control app.
This device uses a flow metre that is not affected by changes in barometric pressure and therefore independent of gas density and suitable for use at high altitudes.
As a reference, we use an extensive dataset of altitudes of gauge zeros measured by GPS collocated at the gauges.
Another model, which also uses solar altitude as an independent variable, was proposed by Robledo and Soler [7].
The first proposal under the Isinglass name, a high-altitude plane to fly at Mach 4 to 5, was considered an insufficient advancement over existing aircraft; the second, much more advanced design, sometimes referred to as Project Rheinberry, was an air-launched, Mach 20 rocket-powered boost-glide aircraft that would use a very-high-altitude trajectory to avoid defenses.
The navigation algorithm is designed as an Extended Kalman Filter which uses the altitude measurements, the Digital Elevation Model and the accelerations measurements coming from the moving frame.
