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In our blog we would like to give you valuable contributions to topics such as ADS-B, Mode-S, MLAT, flight tracking, antennas and 1090 MHz.
If you are interesed in a special subject, please let us know at: support@jetvision.de


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Luftaufsicht leicht gemacht: Jetvision hilft mit Flight Director am Tag der Deutschen Einheit aus

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Koordinierte Luftraumüberwachung mit der Polizei. Durchsetzen einer TMZ/RMZ- sowie einer ED-R Flugzone. Die Spitze der deutschen Politik kommt per Helikopter. Diese Eckdaten sah Sören Kahle, Flugleiter am Flugplatz Halle/Oppin, zum 03.10.2021 auf sich zufliegen. Klar war: Die offiziellen Feierlichkeiten zum Tag der Deutschen Einheit in Halle (Saale) würden den Flugplatz mit etwa 30.000 Flugbewegungen pro Jahr vor ungewohnte Herausforderungen stellen.

“Normalerweise regeln wir den Flugverkehr ganz klassisch per Funk und mit Sichtkontakt. Wenn hier aber der Einsatz von Polizeihubschraubern koordiniert werden soll, dann wollte ich mich nicht rein auf Funksprüche verlassen, wenn es irgendwie möglich ist”, meint Kahle mit Blick auf den Tag der Deutschen Einheit.

 

 

Startbereit zur Luftraumdurchsetzung: Ein Hubschrauber der Polizeistaffel auf dem Flugplatz Halle/Oppin.

 

Unkomplizierte Hilfe aus Bayern

 

Also gab’s den Hilferuf an Jetvision - und es wurde möglich. Kahle wusste, dass die bayrische Firma ein neues Produkt für Flugplätze und kleinere Flughäfen in der Entwicklung hat, was die Flugbewegungen auf einer grafischen Oberfläche in Echtzeit anzeigt. Jetvision-Geschäftsführer Günter Köllner hat, ohne zu zögern, sofort seine Unterstützung zugesagt und stellte innerhalb weniger Tage die Software zur Verfügung: “Halle/Oppin hatten wir im Zuge unseres Markenversprechens, in Deutschland flächendeckend Flugbewegungen bis auf Baumwipfelhöhe darstellen zu können, bereits letztes Jahr mit einer unserer Mobile Sensor Stations ausgerüstet”, erzählt Köllner zur Historie des kleinen Projekts. “Zusätzlich bekam der Flugplatz Zugriff auf unser MLAT-Netzwerk mit seinen 200 Bodenantennen in ganz Deutschland. Somit bekamen sie eine bequeme, filterbare Kartendarstellung mit allen Flugobjekten in 100 km Umkreis”, so der Geschäftsführer.

 

Flugs wurde am Tower in Sachsen-Anhalt ein zweiter Arbeitsplatz eingerichtet, auf dem Flight Director läuft. In der aktuellen Version der Software stehen noch nicht alle Features - die Verbindung zu Kassensystem und weiteren Aspekten der Flughafenlogistik sind etwa noch in Entwicklung. Aber allein die Hauptfunktionen machten Kahle die Arbeit deutlich leichter: “Ich habe mir die Übersichtsgrafik mit den individuell eingezeichneten Flugplatzrunden von Halle/Oppin meist nach Flughöhe oder Geschwindigkeit gefiltert. So sehe ich nur den für uns relevanten Flugverkehr. Zusätzlich kann ich einzelne Flugzeuge selektieren: Wer nur im Überflug ist, wird per Klick ausgeblendet. Wer im An- oder Abflug ist, wird in grün hervorgehoben,” lässt der Flugleiter die Bedienung der Software Revue passieren.

 

jetvision-tdde-halle-02

 

Die Flugleiter Giso Neubauer und Sören Kahle bei der Arbeit mit dem Flight Director.

 

Technik wie auf dem Großflughafen

 

Spannend war der Anflug von Bundeskanzlerin Angela Merkel, die eine Rede bei den Feierlichkeiten hielt. Ihre Maschine sei durch das Kennzeichen im Flight Director leicht zu identifizieren gewesen und die Bahn gegenüber anderen Maschinen war schnell freigemacht. “Und ein kleines Flugzeug musste tatsächlich von einem Polizeihubschrauber abgefangen werden. Wir hatten sie auf dem Display dank der eingezeichneten Flugsonderzonen schnell als Problemfall erkannt und uns mit der Polizei koordiniert”, freut sich der Flugleiter.

 

“Die hohe Präzision und die übersichtliche Darstellung erleichtern Entscheidungen ungemein. Gut möglich, dass wir den Flight Director dauerhaft behalten. Damit war es, wie für einen großen Flughafen zu arbeiten.”, sagt Kahle rückblickend. Köllner wirft nicht ohne Stolz ein: “Nur mit präzisieren Daten! Große Flughäfen verlassen sich auf Radarsysteme. Die enthalten durchaus weniger Daten als unser Netzwerk, was aus den Signalquellen ADS-B, MLAT und FLARM die Position von Fliegern sehr genau trianguliert. Und das auch in Flughöhen von 30-500 m, um die Flugkundschaft von kleinen und mittelgroßen Flughäfen sowie Flugplätzen zuverlässig auf dem Schirm zu haben.”

 

Das Jetvision Produkt Flight Director, eingesetzt am Flugplatz Halle/Oppin zur Luftraumaufsicht anlässlich des Tages der Deutschen Einheit am 03.10.2021. Mehr Infos unter https://shop.jetvision.de/epages/64807909.sf/de_DE/?ObjectPath=/Shops/64807909/Categories/jetvision_Flight_Director

 

Flight Director - Live Mitschnitt, Tag Dt. Einheit, 03.10.21 Flugplatz Halle/Oppin | Jetvision

Live Mitschnitt - Standard-Ansicht mit implementierten Platzrunden in Halle/Oppin, sowie ED-R und RMZ/TMZ Flugzonen.

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Streetview - Live Mitschnitt, Tag Dt. Einheit, 03.10.21 Flugplatz Halle/Oppin | Jetvision

Live Mitschnitt - Streetview mit eingebundenen Luftraumzonen.

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ATC-Radarview - Live Mitschnitt, Tag Dt. Einheit, 03.10.21 Flugplatz Halle/Oppin | Jetvision

Live Mitschnitt - ATC-Radarview mit Vektordarstellung der Flugbewegungen und eingebundenen Luftraumzonen.

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Jetvision Multilateration Network providing results around New York

The Jetvision Multilateration Network has now started to provide precison results for flights in New York.

mlat-over-ny-002-cut
(MLAT track in color, ADS-B track in dashed black)

After setting up a 3rd Radarcape/Air!Squitter there we now can provide MLAT results in some parts around the city.

This map shows actually observed aircraft locations:

mlat-over-ny-003

Blue is altitude above 7000ft, orange, red and brown towards low altitude
 

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ISO 9001 Quality Management

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(DE)
Qualität wird bei Jetvision schon immer groß geschrieben. Bei der Herstellung, Endkontrolle, im Vertrieb und mit unseren Kunden waren und sind wir immer bestrebt ein sehr hohes Qualitätsniveau zu erreichen. Unsere Bewertungen sprechen für sich und bescheinigen uns die Anerkennung durch unsere Kunden. 

Unsere etablierten Prozesse in der Hard- und Softwareentwicklung, im Vertrieb und mit unseren Lieferanten, Datenschutz usw. haben wir nun nach dem anerkannten Industriestandard ISO 9001 zertifizieren lassen. Dazu hat eine unabhängige externe Zertifizierungsstelle unsere Prozesse auditiert. Das Zertifikat belegt, dass Jetvision nun jährlich neu geprüft wird seine Prozesse der EN ISO 9001 Norm entsprechen.

(EN)
Quality has always been a top priority at Jetvision. During production, final inspection, in sales and with our customers, we have always strived to achieve a very high quality level. Our ratings speak for themselves and certify the recognition we receive from our customers. 

We have now had our established processes in hardware and software development, in sales and with our suppliers, data protection, etc. certified according to the recognized industry standard ISO 9001. For this purpose, an independent external certification body has audited our processes. The certificate proves that Jetvision is now audited annually and that its processes comply with the EN ISO 9001 standard.

Zertifikat_ISO_9001_englisch

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More about: 9001, ISO, ISO9001, Quality
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Is it a simple dongle in the Air!Squitter?

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Currently we're quite often asked if there is a dongle inside the Air!Squitter? No, there isn't!

The ADS-B receiver section of the Air!Squitter is equal to the Mode-S Beast and Radarcape. Both based on a FPGA and highly optimized SDR algorithm. Just we left some options away, like video out and antenna diversity.
A dongle based receiver never reaches the sensitivity of our receiver, and it never provides high precision Multilateration, because it has no GPS timestamps.

Just for the FLARM option we're using a dongle in parallel, and even here not just the cheap R820T2 dongle but the significantly better RTL-SDR dongle.

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RTL1090 IMU Software

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Several of our users when installing RTL1090 software report a problem like "No internet connection" or similar. This was due to some old historic software in some kind of caches and link constrcuts which were not under our control. Jetvision now provides a downloadable archive under https://www.jetvision.de/manuals/rtl1090imu.zip and more information at rtl1090.com.

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More about: Dongle, rtl1090
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FLARM Range Improvement

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English Version

German Version

FLARM Range Improvement

A well-known shortcoming of many FLARM systems in airplanes is the low reception range. Many users wish for an improvement here and would like to receive other FLARM equipped aviators at a greater distance.

Why is an improvement in range desired? On the one hand, the area of "situational awareness" cannot be large enough; on the other hand, the low standard range of fast airplanes makes little use, since the reaction time is usually too short. Not least because of this, a larger foresight is desirable for the glider pilots, because then other gliders can be recognized in a good thermals far away.

Technically, the increase in the reception range can only be solved by a higher sensitivity of the receiving system, since the transmission parameters of the FLARM devices are fixed and must not be changed. A simple preamplifier between the antenna and the FLARM device is not applicable here, because FLARM devices also transmit, which would destroy any normal receiver preamplifier, and the transmission signal would not reach the antenna.

Jetvision now has solved this problem and developed two new products: 
FLARM BOOSTER  and FLARM BOOSTER PLUS. An optimized low-noise preamplifier typically increases the range of the FLARM device up to four times, and bypasses the transmission signal unmodified. Switching from receive to transmit is done automatically. Existing antennas can be used with the FLARM BOOSTER, the FLARM BOOSTER PLUS comes with an attached optimized antenna. Both devices can be powered over the antenna cable (5V-15V), which greatly simplifies the installation of the preamplifier or the antenna.

 

FLARM Reichweite verbessern

Ein bekanntes Manko vieler FLARM Systeme in Flugzeugen ist die geringe Empfangs-Reichweite. Viele Anwender wünschen sich hier eine Verbesserung und möchten andere mit FLARM ausgerüstete Flugzeuge auch aus größerer Entfernung empfangen.

Warum ist eine Verbesserung der Reichweite gewünscht? Zum einen kann der Bereich der „Situational Awareness“ nicht groß genug sein, zum anderen nutzt die geringe Standard-reichweite bei schnellen Flugzeugen wenig, da die Reaktionszeit meist zu kurz ist. Bei den Segelfliegern ist nicht zuletzt auch deshalb eine größere Vorausschau erwünscht, da dann andere Segler in einer guten Thermik auch weit entfernt erkannt werden können.

Technisch gesehen ist die Vergrößerung der Empfangsreichweite nur durch eine höhere Empfindlichkeit des Empfangssystems zu lösen, da die Sendeparameter der FLARM Geräte feststehen und nicht verändert werden dürfen. Ein einfacher Vorverstärker zwischen Antenne und FLARM Gerät ist hier nicht anwendbar, da FLARM Geräte auch senden, was jeden normalen Vorverstärker zerstören würde, und das Sendesignal nicht mehr zur Antenne käme.

Jetvision hat sich dieser Problematik angenommen und zwei neue Produkte entwickelt: FLARM BOOSTER und FLARM BOOSTER PLUS. Ein optimierter und rauscharmer Vorverstärker erhöht die Reichweite des FLARM Gerätes typisch bis zum Vierfachen, und leitet das Sendesignal unverfälscht durch (Bypass). Die Umschaltung von Empfang nach Senden erfolgt dabei automatisch. Mit dem FLARM BOOSTER können vorhandene Antennen benutzt werden, der FLARM BOOSTER PLUS kommt mit einer auf ihn zugeschnittenen, angebauten Antenne. Beide Geräte können über das Antennenkabel mit Strom (5V-15V) versorgt werden, was den Einbauort des Vorverstärkers oder der Antenne erheblich vereinfacht. 

FLARM Reichweite

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More about: 868, 868 MHz, FLARM
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Yagi 1090 MHz Antenna

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Over the christmas holiday our Radarcape demo station has got a new yagi towards Munich airport EDDM/MUC in order to improve the tracking of ground traffic. The airport is around 30 km east from the location of Jetvision headquarters but a not fully free line of sight. The Radarcape demo station for this purpose is equipped with the 2 channel antenna diversity Radarcape. Such a Radarcape-2CH is equipped with two independant antenna inputs, one connected to an omni directional A3-ADSB antenna. The second input is connected to a home made 2.5m long yagi antenna.

Because there are no such long yagis for ADS-B on the market our Jetvision member Guenter has constructed this experiemental light weight (1kg), 2.5m long yagi 1090 MHz antenna with 27 elements. Its gain is 16.5dB (18.7dBi). This, within our experience, will truely be reached. In order not to be obstructed by other metallic elements on the mast the yagi is mounted on a bracket. Due to the light weight design mounting was even possible during a local storm.

The result of this is a drastic improve of the track of ground based vehicles at the airport, for example snow plowing trucks during winter time. The antenna also extends the range of the Radarcape demo towards east, where regularily 450 km distant aircraft can be observed. There is still some room for improvement, vehicles that are hidden between the buildings may be trackable with some more gain and picking up reflections. For that purpose an even longer yagi, with some 5-6m length, is in our thought.

If there is interest, we are willing to create these yagis as commerical products for customers, too. Please let us know on our support line (support@jetvision.de)

Ground traffic on Munich airport while cleaning the runway at January 17th, 2018

EDDM Ground View ADS-B with Yagi 1090 MHz

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Antennas at Jetvision headquarters:
Center: 2.5m long Yagi antenna, Very left: A3-ADSB for Radarcape demo, Very right: Active Diapason for Flightradar24 and for FLARM (dl4mea), unused experimental antenna.

Yogi 1090 MHz high gain

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What actually is Mode-A/C, Mode-S and ADS-B? A brief overview.

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Radar isn't a very old technology. Developed during WW2, it is 70 years old. Early radar was just to detect objects in the air. This was done by transmitting a powerful signal and waiting for the reflection from the flying object. The time between transmission and reception was twice the distance of the object. The position of the antenna provided the angular position. Something we still display even on modern systems. Such traditional systems are called primary radar.

Mode-A/C: 

However, due to geometry the altitude resolution on primary radar was not provided (or very inaccurate in systems with several beams). Also, if two aircraft were flying nearby, there was no identification provided for those bright spots on the screen. Due this demand a system was introduced permitting the aircraft to modify the received pulse: Using 12 bits, it returns either altitude or the squawk identification. The radar station has two request patterns which it transmits towards the aircraft, and the aircraft responds with either a Mode-A pattern for squawk or a Mode-C pattern for altitude. The pattern itself does not contain any information about its kind, so only the one who has requested that info will know how to post process. As a passive receiver such as we are, it is that we only hear a  number between zero and 4095, but we don't know the question.

Mode-S:

With growing air traffic, air traffic controllers required more information about the aircraft. Also, they wanted to get control over the transmissions in a crowded airspace. This is when Mode-S became introduced. Not at least the "S" stands for "Selective". Mode-S transmissions contains some more information like higher resolution altitude, aircraft capabilities and identification. As a passive listener we now got the capability to distinguish between several formats and collect information about each single aircraft.

ADS-B:

Last, one special frame format within the Mode-S protocol, so called DF-17, became introduced to indicate the position of the aircraft and some more information. In fact ADS-B is only one message within Mode-S. It requires 2 DF-17 frames to calculate the position unambiguous, the so called even and odd formats. 

Localisation using Mode-A/C, Mode-S and ADS-B:

Our Radarcape and the Mode-S Beast can receive Mode-AC messages and output them on the binary ports. But these messsages do not have position information within. They cannot be used for localisation within the processing capabilities of a Radarcape.


Also Mode-S does not contain location information, but as they have enougth information to distinguish among each other and combining data of at least 3 Radarcape with a precision time stamp and a process called Multilateration (MLAT) we are able to estimate the position of the aircraft from Mode-S transmissions.
Finally, using ADS-B transmissions, the aircraft directly tells us where it believes to be or where it wants us to think it currenly is.

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More about: ADS-B, Beast, Mode-A/C, Mode-S, Radarcape
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Munich Airport Running Event 2017

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Members of the Jetvision team have successfully joined the 25th anniversary of the Munich airport running event. Participating on 5km, Florian (former shipping agent) managed a 4th place, while Elfriede (packaging and customs) and Günter (CEO) took the challenge of the 21km half marathon distance. The beautiful track went from the airport to the river Isar, along its meadows down to Freising and back to the airport on the other side of the river. First half was unusually hot and extremly humid, surely not ideal for running. Elfriede, with a time of 2:06:50 achieved 1st place in her age class and has won a nice trophy. Günter, still suffering from remains of a flu, anyway managed 2:11:32 hours. We say thanks to EDDM/MUC airport team for this great race and hospitality.

Airport1Airport2

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Explaining Noise Figure and Gain

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We do see various offers for any kind of preamplifiers that are promising wonders, so let me give an explanation for the true important factors when using such devices. During my active time at ham radio I was very active in earth-moon-earth communication, that is sending signals to the moon and getting the echo back, up to 5.6 GHz, far beyond the ADS-B frequency of 1090 MHz. This is one of the most sophisticated operational modes in amateur radio, and needs high transmission power as well as most sensitive receivers. This knowledge was brougth into the receiver design of the Mode-S Beast as well as the Radarcape.

Now we do see a lot of preamps on the market. Most of the time gain is given for them, but the more important value of noise figure is missing. There are synonyms for both that can be understood easier:

  • Gain is like brightness of a monitor
  • Noise figure is contrast or somehow the minimum black level

You may quickly understand by these synonyms, once you have destroyed the black level of your picture into a kind of grey, you no longer never can see the small nuances of weak black symbols on your screen. It is the same with radio signals: Once you have destroyed the noise figure, you never will get it back. Even turning the brightness on (= adding gain), you never will recover the true cold black on your screen but instead simply amplify your grey even more.

This brings me to the cable: A cable is attenuation. With our video screen, this is similar to a milky glass in front of it. So you don't see the nice pure black any more but a little bit of grey. Of course, your bright symbols still appear readable. If now you insert an amplifier, the bright symbols will become brighter, but also the grey becomes brighter. But the weak nuances of black are lost.
However, if you amplify before passing the lossy section, you will amplify the nuances of black we're talking about, and they may be still readable behind the attenuation.

Even worse, electronic devices may become overloaded by the shiny bright parts. So this means with an amplifier after the cable and in front of the receiver, you may make things even worse. Only if your device is really deaf or has a lot of internal losses, an amplifier in direct front of the antenna input will improve the situation.

Our Active Diapason antennas for 868MHz (FLARM) and 1090 MHz (ADS-B) are equipped with an amplifier directly connected to the antenna element, which is the pure optimum. Their noise figure is somewhat 1 dB, a quite reasonable value for an antenna that partly sees warm earth within its diagram (less than, say 0.8 dB, only makes sense for space pointing antennas). They are sold with 20 m cable because the gain should not overdrive the receiver, and because this cable attenuation is completly knocked out due to the low noise figure.

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