Geo_ge

4 ms·

1.
by Geo_ge 5mo ago
Decreased vertical precision is an artefact of measurement geometry more than e.g. number of frequencies. Horizontal position has the benefit of having satellites at almost all azimuths. But the vertical position estimate only gets satellit
2.
by Geo_ge 5mo ago
There is a lot of talk of military uses here, but this technique is also used for environmental monitoring. GNSS interferometric reflectometry (GNSS-IR) uses navigation satellites as the transmitter for a bi-static radar. The measurement de
3.
Advanced Astrology Software for Windows(halloran.com)
2 points by Geo_ge 7mo ago|0 comments
4.
Earth's Rotation Limits IBIS Performance to 6.3 Stops(thecentercolumn.com)
5 points by Geo_ge 8mo ago|0 comments
5.
by Geo_ge 10mo ago
Oh wow, cool to see this on HN! I'm a postgraduate researcher working on GNSS interferometric reflectometry (GNSS-IR), a related but slightly different technique. I'll shout out this awesome open source project, where you can use
6.
by Geo_ge 1y ago
You've got exactly the right idea, except "cross compare" is underselling it :) Here's a previous thread on this topic[0]. For each (receiver, satellite) pair, you can calculate the TEC along the signal propagation path
7.
by Geo_ge 1y ago
Maybe a global Moran's I test? https://en.m.wikipedia.org/wiki/Moran%27s_I Create the spatial weights matrix with great circle distances?
8.
Air traffic control outage disrupts flight in Oceanic airspace(nzherald.co.nz)
2 points by Geo_ge 1y ago|0 comments
9.
by Geo_ge 1y ago
Aerial survey LiDAR can process multiple returns from a single laser pulse. So, some energy might be reflected back from a leaf, but some energy will pass through (or around) the leaf, hit the ground, then reflect back to the sensor. Some s
10.
by Geo_ge 1y ago
A raw point cloud is run through a series of processing steps to label each point with a class, e.g. "Ground", "Low/Medium/High Vegetation", "Building", "Transmission Tower", etc. https:&#x
11.
by Geo_ge 1y ago
I went through a similar process recently while building a solar powered Raspberry-Pi based GNSS receiver. (like the OP) I originally looked at a very low power/speed GPIO modem, but it wasn't very stable and not really suitable f
12.
by Geo_ge 1y ago
I'm running a Raspberry Pi based GNSS receiver from a 26 Ah SLA battery and an 80W panel. Just passed 2 weeks of uptime in a cloudy period of southern hemisphere autumn. A monte carlo simulation using historical conditions said it had
13.
End of an era: Landsat 7 mission takes final images(usgs.gov)
273 points by Geo_ge 2y ago|48 comments
14.
FIDE world chess championship decided in rapid tiebreaks(chess24.com)
251 points by Geo_ge 3y ago|174 comments