Michael Margaras (@SV1CAL) header
Michael Margaras (@SV1CAL) profile picture
Αττική, Ελλάς
Joined May 2019
Photo by Michael Margaras (@SV1CAL)Photo by Michael Margaras (@SV1CAL)Photo by Michael Margaras (@SV1CAL)Photo by Michael Margaras (@SV1CAL)Photo by Michael Margaras (@SV1CAL)Photo by Michael Margaras (@SV1CAL)Photo by Michael Margaras (@SV1CAL)Photo by Michael Margaras (@SV1CAL)Photo by Michael Margaras (@SV1CAL)Photo by Michael Margaras (@SV1CAL)
Just finished copper plating my 3D printed 8 GHz dual mode feed ! I plan on using it for X-Band weather sat reception. This is a down-scaled / resimulated version of the 1296 MHz W2IMU/N2UO dual mode septum feed.
10
18
1
136
Hi Zhivko @iskra_fires , Here is the shared folder where I just uploaded some CADU files. drive.google.com/drive/folde…
1
2
170
Michael Margaras retweeted
If you run a station copying polar-orbiting weather satellites and you're within reach of the Balkans, one extra pass a night isn't noise, it's data — sometimes the difference between catching a fire at 2am and hearing about it from a farmer at sunrise. Reply or DM.
1
1
1
65
Michael Margaras retweeted
What we need, technically: raw HRPT/AHRPT downlink from NOAA/MetOp AVHRR (L-band, ~1698–1707 MHz) or raw CADU frames before any vendor processing — SatDump output works fine. We do our own calibration and detection on it. Coverage gap is 41–44N, 22–29E, night passes especially.
1
1
42
Michael Margaras retweeted
Proof it works: Michael in Athens sent us a raw MetOp AVHRR capture that caught a farm fire burning overnight in southern Bulgaria — missed by our geostationary feed and by FIRMS, decoded straight from the CADU stream, nothing else involved.
1
2
63
Zhivko @iskra_fires has set up a fire alert system based on publicly available satellite data. The alerts are sent directly to 13 firefighting volunteer formations. To fine-tune the code, he needs CADU files (MN2-3/4, Metop, etc.) captured at night covering Bulgaria. 1/2
1
390
Michael Margaras retweeted
What it cannot do, since that matters more: Two of our main geostationary products are still demonstrational — the crews are told which. A small fire inside a village falls under the pixel; we missed one on 13 Aug while catching a 550-decare forest fire 40 km away.
1
58
Michael Margaras retweeted
Measured latency, sensing to alert: geostationary 15–25 min MetOp AVHRR 58–113 min (global stream) VIIRS via FIRMS 114–130 min The polar sensors see the small and the night fires, and they reach us an hour and a half late. That is the number that decides everything else.
1
66
Michael Margaras retweeted
Where it stands today: · 20 channels — 14 volunteer formations, the forest agency, a park guard service · 814 alerts for 301 separate fires · 12 satellites in the stream · burned area measured on Sentinel-2 for 68 fires, about 3000 ha
1
57
Michael Margaras retweeted
ISKRA is a wildfire early-warning system built by a volunteer fire formation in Bulgaria. Satellites see the fire, the system works out where it is and what is around it, and a card lands with the duty volunteer. Running since late July 2026. Still early.
1
61
Ideally, the fire alerts could even be generated by SatDump (?) ... For more information, please visit: ISKRA: iskra.gamera.bg/en/ Details on CADUs etc: nitter.gq/iskra_fires Please share ! 2/2 @petermeteor @Aang23 @original_lego11 @iw0ehe @JM @redplanet00 @UngerKonrad
2
1
249
Landsat 8 , 2282.3 MHz , 8:42 UTC Simultaneous RHCP / LHCP RX. A GRC flowgraph streams over UDP to two SatDump instances.
1
4
54
2,560
NOAA 20 , AOS 10:30 UTC, 7812 MHZ
17
251
NOAA 21, AOS 10:53 UTC, 7812 MHz Dust plume travelling towards Greece is clearly depicted affecting visibility and air quality in Athens today.
2
14
381
Experimenting with S/X feeds, now replacing the S band patch with a precisely cut FR4 board . The ground plane has the phasing circuit on the back. All feeds below employ 3-point sequential feeding. Showing two single pol (L and R) feeds and a dual simutaneous L+R one.
Working on a dual S/X feed supporting simultaneous RHCP/LHCP RX . There are 2x S band BPFs, 2x LNAs connected to Lime's Ch1/Ch2. A simple GRC flowgraph streams over UDP to 2 SatDump instances. The coupler/120 deg phase shifter has been based on Maarten Baert's inspiring work.
4
38
2,611
FENGYUN 3D, AOS 12:49UTC, 7820 MHz
1
14
242
AQUA , AOS 12:34 UTC , 8160 MHz
12
216
Metop-B, AOS 07:10 UTC Metop-C, AOS 07:55 UTC
1
10
230