Page Comparison

Jan 25 2022. 

article from prior work: ADS-B.pdf

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Try this: https://www.rtl-sdr.com/rtl-sdr-quick-start-guide/

Nope. 

Try this: sudo port install gqrx

had to 'accept' Xcode license- sudo xcodebuild -license

then 

sudo port install gqrx

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Flight levels for northbound vs southbound air traffic over Chile are typically based on the hemispheric rule, also known as the "East/West rule" or "RVSM (Reduced Vertical Separation Minimum) rule". However, since Chile is in the Southern Hemisphere, the rule is applied differently compared to the Northern Hemisphere. Here's how it generally works:

1. Northbound traffic (odd flight levels):
   • FL290 (29,000 feet)
   • FL310 (31,000 feet)
   • FL330 (33,000 feet)
   • FL350 (35,000 feet)
   • FL370 (37,000 feet)
   • FL390 (39,000 feet)
   • FL410 (41,000 feet)
2. Southbound traffic (even flight levels):
   • FL280 (28,000 feet)
   • FL300 (30,000 feet)
   • FL320 (32,000 feet)
   • FL340 (34,000 feet)
   • FL360 (36,000 feet)
   • FL380 (38,000 feet)
   • FL400 (40,000 feet)

Key points to note:

1. This is the opposite of what's used in the Northern Hemisphere, where eastbound flights use odd flight levels and westbound flights use even levels.
2. The actual flight levels used may vary based on specific air traffic control instructions, weather conditions, or other operational factors.
3. Below FL290, different rules may apply, and separation is often managed by air traffic control based on various factors including terrain and traffic density.
4. Some high-altitude aircraft may operate above these levels, following specific procedures and clearances.
5. Local variations or exceptions may exist, especially near major airports or in areas with complex airspace structures.

Tried out using API key access to Flight Aware database. Used old user account under astrostubbs@gmail.com 

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This next script almost works... finds time closest to current one and spits out winds at 30,000 ft 

Windy6.sh

So (u,v) is a vector with x and y components of wind in (W to E, S to N) coordinate system. But our definition of azimuth is from y axis rotating towards x axis. 

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1. run plane-finder every minute or so. Identify any new planes that are above some elevation angle cutoff, say 15 degrees. Start a data file per plane in a folder for that night
2. accumulate track information for each plane above threshold elevation angle. 
3. Use that track information and winds aloft to create contrail track for each plane. We can also predict this 5-10 min into the future.
4. Use wind-aloft direction to determine contrail transport direction- is it along or cross-contrail? Make photometry assessment.  
5. send contrail mask file to scheduler. 
6. We can validate all this in daytime with all-sky Canon camera. 

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July 26, 2024

For flying weather balloons ourselves, to measure temp and humidity: 
Visala downlinks are 403-406 MHz, can read it with SDR radio

High pass and low pass RF filters from Minicircuits: 
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ordered July 26 2024. 

Rubber duckie antenna:

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eventually can use a Yagi:

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and this? 

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a resource: https://overlookhorizon.com/how-to-launch-weather-balloons/inflate-weather-balloon/ 

From Vaisala: 
RS 41 SGE
RI 41 ground check station and associated software
FB 13 weight and clamp

weather balloons from Totex

There is also a contrail predictor avail as a plug-in add-on to Windy. It uses the Appleman criteria for exhaust contrail prediction. 

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quote from Vaisala, asked Helen to place this order on July 30:
Vaisala_Q-00258333_Harvard University_2024-7-30.pdf

Windows software for decoding Vaisala RS41:
http://escursioni.altervista.org/Radiosonde/

Rubin All-sky camera data and access

software installation on Windows for radiosonde monitoring