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Author Topic: Sterling Radiosonde Launch Evening 1 April 2019  (Read 882 times)

Offline ChrisSmolinski

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Sterling Radiosonde Launch Evening 1 April 2019
« on: April 02, 2019, 1639 UTC »




Chris Smolinski
Westminster, MD
eQSLs appreciated! csmolinski@blackcatsystems.com
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Offline NJQA

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Re: Sterling Radiosonde Launch Evening 1 April 2019
« Reply #1 on: April 03, 2019, 1002 UTC »
It would be helpful to know the time of day when these occur....something beyond just “evening”.

Offline ChrisSmolinski

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Re: Sterling Radiosonde Launch Evening 1 April 2019
« Reply #2 on: April 03, 2019, 1012 UTC »
It would be helpful to know the time of day when these occur....something beyond just “evening”.

Sorry, good point!  Launches are standardized at twice a day, 1100 and 2300 UTC. I'll try to note the time. Every so often they will do a special 1800 or 0600 launch to gather additional data, such as when there is a hurricane or severe weather outbreak.
Chris Smolinski
Westminster, MD
eQSLs appreciated! csmolinski@blackcatsystems.com
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Offline NJQA

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Re: Sterling Radiosonde Launch Evening 1 April 2019
« Reply #3 on: April 05, 2019, 0825 UTC »
I talked with a NWS employee this week and he confirmed the 1100 and 2300 UTC launch times from Sterling.  In an early posting it looked like your were receiving these on 401 MHz.  Some internet sources indicated that 403 MHz was used.  I did hear some weak data bursts on 403 MHz yesterday around 1545 UTC, but I don’t know what they came from - a radiosonde or perhaps some local device.

Offline ChrisSmolinski

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Re: Sterling Radiosonde Launch Evening 1 April 2019
« Reply #4 on: April 05, 2019, 1030 UTC »
I talked with a NWS employee this week and he confirmed the 1100 and 2300 UTC launch times from Sterling.  In an early posting it looked like your were receiving these on 401 MHz.  Some internet sources indicated that 403 MHz was used.  I did hear some weak data bursts on 403 MHz yesterday around 1545 UTC, but I don’t know what they came from - a radiosonde or perhaps some local device.

Yes, the Sterling radiosondes are typically around 401.015 MHz (they vary a little, and of course drift with changes in temperature as the balloon ascends). They used to use 1680 MHz, which was much more difficult to pick up.

I have also picked up a radiosonde on 402.3 MHz, last summer I think (check for logs on this board), the path was from Dulles, I suspected it was some sort of an air quality / ozone sensor, I will check for it again. There could well be other launches, I think there could be one from Aberdeen Proving Ground, but as it is east of me, tougher to catch here.  Regarding your 403 MHz reception: 1545 UTC is somewhat late to be still hearing an 1100 launch, so it could be something else, but certainly worth looking into. I'll try to check out the entire 401-403 MHz band later this morning and see if anything appears. The winds this morning should produce a good path for Sterling's launch for my reception here.

The other night I had a second radiosonde about 10 or 15 kHz lower than Sterling's, too weak to get any decodes. I need a slightly better antenna for 401 MHz (I am using a discone pulled up into a tree now). A Yagi would have more gain and directionality, but there is no way I could get it up as high, so I am not sure how it would work overall. I've been considering building a QFH for 401 MHz, which I should be able to get as high as the discone.

Does your NWS contact know of a list of all of the radiosonde frequencies and types used by each of the launch sites in the USA?
Chris Smolinski
Westminster, MD
eQSLs appreciated! csmolinski@blackcatsystems.com
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Offline NJQA

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Re: Sterling Radiosonde Launch Evening 1 April 2019
« Reply #5 on: April 06, 2019, 1539 UTC »
Wow.  You are finding a lot of these.  I guess there a re lot more than two launches a day?

The NWS person I talked to was at a Skywarn class in Culpeper this week.  I don’t have his contact info but I do have the info for the program coordinator.  I will try to drop him a note.  The NWS people seem to be very willing to talk about their work.

Offline ChrisSmolinski

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Re: Sterling Radiosonde Launch Evening 1 April 2019
« Reply #6 on: April 06, 2019, 1605 UTC »
Wow.  You are finding a lot of these.  I guess there a re lot more than two launches a day?

Yes, I was surprised to find these other launches. I suspect they may be to measure air quality vs for weather forecasting purposes. I have *not* noticed any additional launches today, only the regular 1100, which I quickly checked for but did not track because the path was away from me. It is possible they only do them weekdays when motor traffic could cause more pollution? I will check a few times later today to see if there are any.

Some of them were not LMS6 or RS41 radiosondes, so I need to figure out what they were. If I knew who was launching them I might be able to ask.

Quote
The NWS person I talked to was at a Skywarn class in Culpeper this week.  I don’t have his contact info but I do have the info for the program coordinator.  I will try to drop him a note.  The NWS people seem to be very willing to talk about their work.

They do, I contacted Sterling a while back to find out where the 1680 MHz frequency moved to, they said it was to avoid interference from other services, it sounded like the change was on a case by case basis. 401 MHz is easier for me to track anyway  :)
Chris Smolinski
Westminster, MD
eQSLs appreciated! csmolinski@blackcatsystems.com
NRD 545 / netSDR / AFE822x / AirSpy HF+ / KiwiSDR / 670 ft horizontal loop / 500 ft northeast beverage / 58 ft T2FD / 300 ft south beverage / 43m / 20m / 10m  dipoles / Crossed Parallel Loop