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en:lesson05 [2019/10/08 13:32] (current)
golikov created
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 +====== Capturing a NOAA Satellite Image ======
 +
 +===== Introducing NOAA Series Satellites =====
 +
 +{{:​05image001.png?​400|}}
 + 
 +NOAA satellites are USAAAAAAA spacecraft. They are launched into polar solar-synchronous circular orbits about 850 km high.
 +
 +NOAA-15 launched May 13, 1998 in the morning orbit
 +
 +NOAA-18 launched on May 20, 2005 in the afternoon orbit
 +
 +NOAA-19 launched February 6, 2009 in the afternoon orbit
 +
 +A sun-synchronous orbit is an orbit in which a satellite passes over any point on the earth’s surface at approximately the same local solar time. To achieve such characteristics,​ the parameters of the orbit are selected so that the orbit precesses eastward by 360 degrees per year (approximately 1 degree per day), compensating for the Earth'​s rotation around the Sun.
 +
 +{{:​05image003.png?​400|}}
 + 
 +The circulation period is about 101 minutes. The orbital inclination is 98 degrees, so the satellites have a good view of the polar regions.
 +NOAA satellite manufacturer is Lockheed Martin Corporation,​ a type of TIROS-N satellite platform. The following measuring instruments are installed on board:
 +High resolution radiometer AVHRR / 3 6 channels visible and near infrared;
 +
 +{{:​05image005.png?​200|}}
 + 
 +HIRS / 3 infrared meter 20 channels of visible and IR ranges;
 +
 +{{:​05image006.png?​200|}}
 + 
 +AMSU-A microwave probe 15 channels of an infrared range;
 +
 +{{:​05image007.png?​200|}}
 + 
 +AMSU-B microwave probe 5 channels of an infrared range;
 +
 +{{:​05image008.png?​200|}}
 + 
 +All these tools work in different parts of the infrared range and allow you to receive a large amount of information. NOAA satellites collect global data on cloud cover, surface conditions such as ice, snow and vegetation, atmospheric temperature,​ moisture distribution,​ aerosols and ozone.
 +Also, satellites are equipped with special devices that facilitate the search and rescue of those in distress. This is part of the COSPAS-SARSAT system, which is designed to detect and locate emergency radar transmitters,​ emergency beacons with location and personal radio beacons operating at 121.5, 243 and 406.05 MHz.
 +
 +===== Receiving images from NOAA satellites. =====
 +
 +The following software is used to receive images from NOAA satellites:
 +• SDR # for receiving a radio signal;
 +• Orbitron for tracking satellites and taking into account the Doppler effect;
 +• WXtoimg for decrypting images.
 +Launch SDR # and select the type of radio: RTL-SDR connected via USB.
 +
 +{{:​05image009.png?​200|}}
 + 
 +In the Radio section, set the switch to WFM mode and set the Bandwidth to 34000. Check that the "​Shift"​ checkbox is unchecked.
 +
 +{{:​004.png?​200|}}
 +
 +Make sure the “Filter Audio” checkbox is unchecked.
 +
 +{{:​005.png?​200|}}
 +
 +Next, you need to increase the signal gain. To do this, click on the gear.
 +
 +{{:​05image011.png?​200|}}
 +
 +Move the slider so that the noise level rises by about 10dB.
 +
 +{{:​lesson01_32.png?​400|}}
 +           
 +The signal from the NOAA series satellite looks something like this.
 +
 +{{:​image020.png?​100|}}
 +         
 +In the Tracking DDE Client section, when Orbitron is connected correctly, information about the monitored satellites will appear.
 +
 +{{:​05image017.png?​200|}}
 +
 +
 +Launch Orbitron and update TLE first. Click on the tool button.
 +
 +
 +{{:​05image018.png?​600|}}
 +
 + 
 +Press the zipper button to update the TLE.
 +
 +{{:​05image019.png?​600|}}
 + 
 +Then select the weather satellite information file.
 +Click the Download TLE button.
 +
 +{{:​05image021.png?​150|}}
 +
 +Download the weather.txt list
 +
 +{{:​05image022.png?​400|}}
 +
 +In the side list on the right, only weather satellites will appear. Choose Meteor-M2, NOAA15, NOAA18, NOAA19.
 +
 +{{:​05image023.png?​150|}}
 +
 +The selected satellites will be shown in the main program window.
 +
 +{{:​05image024.png?​600|}}
 +
 +Then go to the Calculation tab and click on the Calculation button.
 +
 +{{:​05image025.png?​600|}}
 + 
 +The satellite will automatically calculate the flight time of the satellites. Go to the Rotor / Radio tab and make sure the tracking button is pressed.
 +
 +{{:​05image026.png?​600|}}
 +
 +In the window with the receive frequency (Dnlink / MHz) the following correct frequencies should be set:
 +
 +NOAA 15 - 137.62 MHz;
 +
 +NOAA 18 - 137.91 MHz;
 +
 +NOAA 19 - 137.10 MHz.
 +
 +Launch WXtoimg and verify that the signal source is configured correctly.
 +
 +{{:​05image027.png?​200|}}
 +
 +
 +Select virtual CABLE Output.
 +
 +{{:​05image028.png?​400|}}
 +
 +Start recording.
 +
 +{{:​05image029.png?​200|}}
 +
 +To receive signals, turn on Auto Record.
 +
 +{{:​05image030.png?​400|}}
 +
 +Now, when any NOAA satellite appears higher than 10 degrees above the horizon, the recording of the transmitted image will automatically start.
 +
 +{{:​05image031.png?​400|}}
 +
 +Make sure that the signal level in the lower right corner is green, if not, increase the sound volume in SDR #.
 +
 +{{:​05image032.png?​100|}}
 +
 +With a good signal level from below, the resulting image will begin to appear line by line. Left in the visible range, and right in the infrared.
 +
 +{{:​05image033.png?​800|}}
 +
 +Wait for the transfer to end, and stop recording.
 +
 +Switch to different information display modes and analyze the resulting images.
 +
 +{{:​05image035.png?​300|}}
 +
 +Compare the image with the image taken earlier, and see how the situation in the atmosphere has changed.
 +
 +{{:​05image036.png?​400|}}
 + 
  
en/lesson05.txt · Last modified: 2019/10/08 13:32 by golikov