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    raffaello.dimartino

    @raffaello.dimartino

    Italia

    For fifteen years I have been involved in the design and installation of AWOS and ATIS stations in Italian airports and some installations in foreign airports.
    I now work in a research company, specifically as a field engineer in the radio frequency communications sector.
    More information can be found on:
    https://www.linkedin.com/in/raffaello-di-martino-03030448/
    or on my web site:
    http://www.kwos.it

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    Website www.kwos.it/ Location Scandriglia Age 50

    raffaello.dimartino Follow
    Italia Utility Control Room Operators Meteorologist

    Best posts made by raffaello.dimartino

    • MeteoTracker – the weather station for those on the move

      On the Facebook pages of KWOS.it , we often show the tests we are carrying out with MeteoTracker: a revolutionary system for measuring, mapping and sharing meteorological parameters on the move.

      meteotracker.jpg

      During a session, the instrument (which is the size of a computer mouse) will measure temperature, humidity and pressure; this data is then sent to an app, which adds GPS coordinates, calculates the altitude and sends all data to the server which also records the route taken by each tracker.

      The software is constantly evolving so there will be many more calculated parameters, such as dew point, QNH (reduced to sea level pressure), a radiation index, etc.

      It is very easy to use: you only have to download the App the first time you use it and you will have to do Bluetooth pairing to recognise the peripheral device. Oncemeteotracker app it is switched on, the smartphone will recognise it automatically, it can then be placed in position on your car thanks to its strong magnets and after a few seconds (time enough to fix it in place) you will be ready to go.
      meteotracker_app.png

      The App consumes little smartphone battery and can easily continue to function in the background.

      tracker_photo_3.jpg

      If you wish to keep it active, it will show you your route on a map, the altitude, temperature or humidity charts, the maximum or minimum temperature registered during the session and obviously, the real-time temperature, altitude and speed.

      During the trip it is possible to take photos with the camera on your smartphone, through the App, which are then sent to the online server so that you can review them on the web portal and are also recorded on your phone so that you can send them with other software.

      The meteorological conditions measured by MeteoTracker and the name of the location obtained from the GPS coordinates is reported on a band which appears across the top of each photograph.

      If you make any stops during your trip, it is worth remembering to press pause to avoid recording temperatures with a high solar radiation error (correct measurement of air temperature works better while on the move, even at low speeds).

      At the end of the trip press stop, and the App will remind you to remove the MeteoTracker from the rooftop of the car.

      Upon arriving back home, you can view your trips on the web platform after registering with a Gmail account.

      Those most attentive and curious among you will notice that there are two circular windows on MeteoTracker, one white and the other transparent,
      meteotracker 2the purpose of which is to make the two tiny temperature sensors located underneath, of 1.5mm on each side, radiate differently. It is precisely here that the

      *patented “dual-sensor differential” system (Radiation Error Correction System, RECS) comes into play, in which two identical sensors are hit by solar radiation with a different, suitably calibrated intensity.

      The temperature difference that the two sensors report (greater when the sun is strong, less when the sun is weak) thus becomes a parameter that allows you to determine and correct the error caused by solar radiation.*

      meteotracker_2.jpg
      In this way, the data reported by MeteoTracker maintains greater accuracy even at a very low speed (when ventilation is very weak, and the radiation problem is particularly noticeable).

      *Furthermore, since shielding is not required, the sensors have greater exposure to the air flow and, consequently, the all-important measurement speed is maintained.

      The RECS system also solves a third problem that would emerge in measurements taken through the classical approach, namely the fact that in the presence of solar radiation the temperature reported by the measurement system would rise as speed decreases and, vice versa, would fall when accelerating:*

      lower speed = less ventilation à greater error due to the sun

      With the patented MeteoTracker system, a counter-reaction is established whereby as the speed decreases, the difference in the temperature values reported by the two sensors increases and therefore the correction factor also increases, which realigns the measured value to the correct data.

      For those who are sceptical regarding this error correction system because of the direct solar radiation that hits the temperature sensor, I recommend the below article which explains how complicated systems, used in the measurements from radiosondes, are based on the same principle of physics, although with very different solutions from the original one implemented on the MeteoTracker sensor:
      Dual temperature sensors with different emissivities in radiosondes for the compensation of solar irradiation effects...

      To be sure of this, however, KWOS wanted to do an experiment, installing a real weather station on a car to which a different method for correcting the measured temperature was applied, by way of the energy balance formula , to prevent the surface of the car distorting its measurements.

      The temperature was recorded and monitored, during a journey of about 40 km in which the travel speed varied depending on the traffic and the orography of the land. We encountered altitudes that ranged from approximately 30 m above sea level up to more than 300 m above sea level.

      The data from the weather station was recorded every 5 minutes, therefore, with a much lower sampling density compared to that of MeteoTracker which is every few seconds.

      Some of the photographs taken during the trip can be seen below, showing the set-up used and the side-by-side monitoring of the two weather stations.

      comparison_meteotracker_ecowitt-car_setup_2.jpg
      comparison_meteotracker_ecowitt-car_2.jpg

      We recorded the following data:

      Time MeteoTracker °C Ecowitt WS80 °C Km/h comparison graph
      17:30 32.5° 32.6° 100
      17:35 32.8° 33.0° 100
      17:40 33.5° 34.0° 42
      17:45 34.1° 33.9° 20
      17:50 32.5° 32.9° 31
      17:55 32.7° 32.3° 0
      18:00 32.1° 32.5° 66
      18:05 31.0° 31.9° 0

      comparison_graph.png
      In our opinion, the values of MeteoTracker are perfectly in line with those of a conventional weather station, also considering the updating speed which in some cases causes the temperature to fluctuate even by half a degree in just a few seconds.

      For the sake of completeness, the values of the other KWOS stations recorded at 18:05 when we reached the office by car were as follows:

      Meteoshield Pro: 32.0° - Apogee: 32.1° - WS80 originale: 33.1° - WS80_corrected: 32.0°meteotracker 080820 2

      Given such excellent performance, we wanted to use MeteoTracker during a long trip in order to observe the stability of the App, the data transmission and the consumption of the instrument.

      In total, we travelled almost 700 km and it was in use for approximately 8 hours. From 100% charge, it indicated 88% when we reached our destination.

      The acquisition time is very fast, allowing observation of even the slightest variations in temperature.

      During the trip, we paused the session when we stopped to get petrol, but we did not pause it when we were stopped in traffic.

      meteotracker 080820 3

      We appreciated the photography function, very good for sending photos to acquaintances and friends or as part of an archive.

      There were some gaps in data transmission unfortunately caused by the prolonged lack of mobile phone coverage.

      From a meteorological standpoint, how the measured data is then used depends on the imagination and the needs of the user. It is certainly useful to observe how the temperature varies if you move to a higher altitude, yet in such a long trip this can depend on the time of day as well, i.e. if you leave at dawn and arrive at 10 a.m.

      For example, by analysing the sections of movements in the Apulia region when we move from one sea to another (Adriatic-Ionian), it is possible to see the different exposure to the sun and the consequent fall in temperature, which is also due to cooler winds.

      meteotracker_080820_3.PNG

      The route along the Adriatic coast is circled in red on the figure to the left. In blue, the passage towards the hinterland. In purple, the route along the Ionian coast.

      This session highlighted all the qualities of MeteoTracker and how easy it is to use. However, we wanted to experiment with another use which was while Trekking in the mountains.

      Although it was not designed to operate at such low speeds, such as during a walk or even while stopped during an uphill climb, we tried installing it onto a backpack under a metal U-shaped bracket. We did this in order to prevent it tracker photo 2

      (to some extent) from getting hit directly by the sun’s rays and to facilitate its task of correcting the temperature at low speed.

      The behaviour was excellent compared, when possible, with the weather stations of the mountain refuges.

      What is certain is that we must avoid standing still under the sun for too long. Overestimation is always lying in wait.

      It therefore shows extreme versatility in the application possibilities for this little gem such that every meteorology enthusiast, every association and research group should have one with them when travelling by car, bicycle or any moving vehicle, including it as one of their standard instruments for monitoring the weather.

      The complete review is here:
      KWOS.it

      You can help the diffusion of MeteoTracker on Kickstarter.com

      posted in Windy Stations
      raffaello.dimartino
      raffaello.dimartino
    • Estimate the rainfall rate with the signal received from a television dish

      This time I present to you a study done some time ago.

      The satellite television or satellite television , is television that reaches users in broadcast or multicast by means of radio waves emitted by transmitters placed on satellites to geostationary telecommunications .

      The transmitted signals are modulated on a carrier to and from the satellite. In general, the types of telecommunications satellite systems differ from each other in their technical characteristics based on the application or intended use (eg broadcasting, satellite telephony, satellite internet, radio localization and radio navigation systems).

      The frequencies used for television setellite , in general, are those of the Ku band (12–18 GHz) , while those for satellite internet are usually on the Ka band (26.5–40 GHz) .

      Rainfade

      While watching a TV show, almost everyone has encountered a loss of signal during a thunderstorm. Contrary to what many believe, it is not the thickness of the cloud cover that attenuates the satellite signals but the concentration of water droplets in the atmosphere and in the clouds themselves . In practice it is the same phenomenon that manifests itself in the operation of a microwave oven. A high- frequency electromagnetic radiation (such as that generated by satellite transmissions and by the Magnetron present in the oven) produces oscillations in molecules that have polarization such as water: by increasing the motion, the energy is converted into heat and the signal becomes weaker.

      The signal received from a radio source can be measured in various ways but in particular, in the world of digital radio communications, a parameter is used that takes into account the number of bits that can be transferred with that particular signal. The value of this parameter called E b / W or e for a television dish is almost always the same during the beautiful days and is dependent on the diameter, the aiming and other small factors that make it slightly oscillate around a base value.

      On such high frequencies the Rain fade is very evident and there are even mathematical methods to calculate it based on the power of the emitted signal, the angle of reception of the dish and other factors. Here is a sample article on how it can affect .

      The KWOS has an image receiving station of the Meteosat Second Generation using a geostationary satellite called EUTELSAT 10th to send them to the ground in broadcast. One of the software used by the system is BDADataEx which allows interfacing the tuner with the PC. This software has the logging function in which it writes the value of E b / W o many times per minute .

      By monitoring this value and with subsequent processing based on checking the daily deviation of the signal or signal drops caused by the passage of the Sun, it is possible to estimate the rain rate.

      BDADataEx

      Here is an example of how it compares to other rain monitoring systems .

      alt text

      On the same image there is also the result of another project based on the same phenomenon: Nefocast

      In addition to the two Rain rates calculated from the signal of the two parabolas, as a comparison, two types of rain gauges have been chosen: double layer tilting rain gauge and a 26GHz mini radar that uses the doppler effect. In addition, the electric field is represented, which is dependent on the electric charge contained within the clouds : the greater the Kvolts / meter recorded, the greater the cumulonenbo that will pass through the survey station.

      Two articles explain how to obtain the Rain Rate from the received signal attenuation:
      Rainfall Detection and Rainfall Rate Estimation Using Microwave Attenuation
      Rainfall measurement from the opportunistic use of an Earth – space link in the Ku band

      posted in General Discussion
      raffaello.dimartino
      raffaello.dimartino
    • RE: Aggiungere il meteo segnalato (icone meteo)

      @Angelo1971 ciao Angelo,
      se vuoi farlo sulla mappa devi selezionare vento.
      Screenshot_2020-11-29-14-37-54-986_com.windyty.android.jpg )

      posted in Non English posts
      raffaello.dimartino
      raffaello.dimartino
    • RE: how to add a webcam?

      Here the instructions

      https://community.windy.com/topic/10423/how-to-add-your-webcam-to-windy?_=1606673023648

      posted in Your Feedback and Suggestions
      raffaello.dimartino
      raffaello.dimartino

    Latest posts made by raffaello.dimartino

    • RE: How to share de data of my different METEOHELIX ws on Windy.com?

      Yes Korina,
      I cannot use directly the Meteohelix website due to the use of Kelvin unit of measure and the impossibility to do conversions.
      So I used my meteohelix plugin for meteotemplate to send also data to Windy.

      I still not have wind sensor and the sigfox raingauge is not working now

      posted in Windy Stations
      raffaello.dimartino
      raffaello.dimartino
    • RE: How to share de data of my different METEOHELIX ws on Windy.com?

      @seb-schmied No I can't as the barani outputs are:

      temperature: in Kelvin - this needs to be converted in °C or °F
      pressure: real in Pa - this needs to reduced to the correct altitude (QNH)

      posted in Windy Stations
      raffaello.dimartino
      raffaello.dimartino
    • RE: How to share de data of my different METEOHELIX ws on Windy.com?

      @seb-schmied Oh I remember now:
      temperature (413.844458007812 kelvin) and 338046000 pressure (that's 3.3 megapascal)

      You're right in my plugin I've done the conversion.
      Ok there is no choise to send pressure data via Meteohelix portal. I cannot do conversions before the JSON generation.

      The barom is in pa and without the altitude correction:

      # Baros
      $pa_in_hpa = 0.01;
      @$weather_data['baromabshpa'] = round( $weather_data['pressure'] * $pa_in_hpa, 2 );
      @$weather_data['baromrelhpa'] = round(($weather_data['baromabshpa'] * pow(1 - (0.0065*$altitude) / ($weather_data['tempc'] + (0.0065 * $altitude) + 273.15),-5.257 )), 2);
      

      Thank you for the link to check the update.

      posted in Windy Stations
      raffaello.dimartino
      raffaello.dimartino
    • RE: How to share de data of my different METEOHELIX ws on Windy.com?

      @raffaello-dimartino I tested it simulating what the website should do and it works.
      The Windy server answers with: SUCCESS

      posted in Windy Stations
      raffaello.dimartino
      raffaello.dimartino
    • RE: How to share de data of my different METEOHELIX ws on Windy.com?

      @seb-schmied Thank you very much.

      This JSON should be OK:

      {
      "stations":[
      {
      "station":0,
      "name":"KWOS_Meteohelix_Rome",
      "lat":41.9896220405185,
      "lon":12.507319807809838,
      "elevation":70,
      "tempheight":10,
      "windheight":10
      }
      ],
      "observations":[
      {
      "station":0,
      "ts":"{timestamp}",
      "tempf":"{temperature}",
      "rh":"{humidity}",
      "baromin":"{pressure}"
      }
      ]
      }

      The web site cron is sending it every 10 minutes (just when the packet arrives from the Sigfox network).
      I still not see anything here:

      https://www.windy.com/station/pws-f05b0b61?41.990,12.507,8

      Unfortunately, I have no feedback on any errors, since I am not the portal manager sending the POST request.

      posted in Windy Stations
      raffaello.dimartino
      raffaello.dimartino
    • RE: How to share de data of my different METEOHELIX ws on Windy.com?

      @seb-schmied oh absolutely don't worry.
      The problem is:

      Barani web site uses the variables with {} which can confuse the JSON.
      I don't know the measure of unit requested by windy and in case are different to the barani I cannot convert to the right one.
      What parameters can I upload to windy? And what are their names?

      posted in Windy Stations
      raffaello.dimartino
      raffaello.dimartino
    • RE: How to share de data of my different METEOHELIX ws on Windy.com?

      @seb-schmied Tested, but due to wrong programming, the web interface doesn't regonize the nested JSON format so it says: JSON error.

      It works only with this format:

      {
      station:0,
      dateutc:"2019-03-15T06:15:34",
      temp:1.2,
      wind:2.8,
      winddir:189,
      gust:3.7,
      rh:76
      }

      The result is: Request failed with status code 500

      I think I will manage it with my Meteotemplate plugin.
      https://github.com/iz0qwm/meteohelix_scripts

      posted in Windy Stations
      raffaello.dimartino
      raffaello.dimartino
    • RE: How to share de data of my different METEOHELIX ws on Windy.com?

      @seb-schmied
      Thank you if windy has similar format to wunderground it's ok.

      I will try too with mine Meteohelix in Rome

      posted in Windy Stations
      raffaello.dimartino
      raffaello.dimartino
    • RE: How to share de data of my different METEOHELIX ws on Windy.com?

      Hello @ltrullem this can be done only by Barani developers.
      You can try asking them.
      There is a way to send data via API calls to Windy, I think this can help the Barani developers.

      I will try asking to Barani, too.

      Please @Korina can you help us on finding the how-to send data via API ?

      Thank you.

      posted in Windy Stations
      raffaello.dimartino
      raffaello.dimartino
    • Estimate the rainfall rate with the signal received from a television dish

      This time I present to you a study done some time ago.

      The satellite television or satellite television , is television that reaches users in broadcast or multicast by means of radio waves emitted by transmitters placed on satellites to geostationary telecommunications .

      The transmitted signals are modulated on a carrier to and from the satellite. In general, the types of telecommunications satellite systems differ from each other in their technical characteristics based on the application or intended use (eg broadcasting, satellite telephony, satellite internet, radio localization and radio navigation systems).

      The frequencies used for television setellite , in general, are those of the Ku band (12–18 GHz) , while those for satellite internet are usually on the Ka band (26.5–40 GHz) .

      Rainfade

      While watching a TV show, almost everyone has encountered a loss of signal during a thunderstorm. Contrary to what many believe, it is not the thickness of the cloud cover that attenuates the satellite signals but the concentration of water droplets in the atmosphere and in the clouds themselves . In practice it is the same phenomenon that manifests itself in the operation of a microwave oven. A high- frequency electromagnetic radiation (such as that generated by satellite transmissions and by the Magnetron present in the oven) produces oscillations in molecules that have polarization such as water: by increasing the motion, the energy is converted into heat and the signal becomes weaker.

      The signal received from a radio source can be measured in various ways but in particular, in the world of digital radio communications, a parameter is used that takes into account the number of bits that can be transferred with that particular signal. The value of this parameter called E b / W or e for a television dish is almost always the same during the beautiful days and is dependent on the diameter, the aiming and other small factors that make it slightly oscillate around a base value.

      On such high frequencies the Rain fade is very evident and there are even mathematical methods to calculate it based on the power of the emitted signal, the angle of reception of the dish and other factors. Here is a sample article on how it can affect .

      The KWOS has an image receiving station of the Meteosat Second Generation using a geostationary satellite called EUTELSAT 10th to send them to the ground in broadcast. One of the software used by the system is BDADataEx which allows interfacing the tuner with the PC. This software has the logging function in which it writes the value of E b / W o many times per minute .

      By monitoring this value and with subsequent processing based on checking the daily deviation of the signal or signal drops caused by the passage of the Sun, it is possible to estimate the rain rate.

      BDADataEx

      Here is an example of how it compares to other rain monitoring systems .

      alt text

      On the same image there is also the result of another project based on the same phenomenon: Nefocast

      In addition to the two Rain rates calculated from the signal of the two parabolas, as a comparison, two types of rain gauges have been chosen: double layer tilting rain gauge and a 26GHz mini radar that uses the doppler effect. In addition, the electric field is represented, which is dependent on the electric charge contained within the clouds : the greater the Kvolts / meter recorded, the greater the cumulonenbo that will pass through the survey station.

      Two articles explain how to obtain the Rain Rate from the received signal attenuation:
      Rainfall Detection and Rainfall Rate Estimation Using Microwave Attenuation
      Rainfall measurement from the opportunistic use of an Earth – space link in the Ku band

      posted in General Discussion
      raffaello.dimartino
      raffaello.dimartino