Tagged: adsb

FlightAware Prostick vs FlightAware Prostick Plus: Review

Recently the FlightAware Prostick Plus was released. The Prostick is a modified RTL-SDR with a LNA built into the dongle. It is optimized for ADS-B reception and works very well due to the low noise figure of the SKY7150 LNA which is used as the first stage LNA. However, due to the increased gain from the LNA it can easily overload from strong out of band signals, such as broadcast FM, DAB, DVB-T and GSM. To eliminate this problem FlightAware recommend using their 1090 MHz filter in front of the dongle. 

The FlightAware Prostick Plus is the same as the Prostick, but the Plus also incorporates a 1090 MHz SAW filter into the dongle itself. The overall cost is about $15.95 USD cheaper than buying the Prostick + Filter combination. See below for a tabulated comparison between the two units.

  FlightAware Prostick + Filter FlightAware Prostick Plus
Price

USA: $16.95 + $19.95 = $36.9 (Buy Prostick) (Buy Filter)

Worldwide: $48.99 + $18 Shipping = $66.99
(Buy Prostick + Filter)

USA: $20.95
(Buy Prostick Plus)

Worldwide: $29.99 + $12 Shipping = $41.99
(Buy Prostick Plus)

LNA + Filter Arrangement Filter -> SKY7150 LNA SKY7150 LNA -> Filter
Filter Specs Type: LC
Passband:
980 – 1150 MHz
Insertion Loss: 1.65 dB
Attenuation: 40 – 50 dB
Type: SAW
Passband:
1,075 MHz – 1,105 MHz
Insertion loss: 2.3 dB
Attenuation: 30 dB 
TCXO Old batches NO.
New batches YES.
YES
Current Draw 330 mA 300 mA
The new Pro Stick Plus RTL-SDR based ADS-B Receiver from FlightAware.
The new Pro Stick Plus RTL-SDR based ADS-B Receiver from FlightAware.

The first thing we notice is that the filter arrangement between the two units is reversed. On the Prostick the filter is external and must be placed before the LNA. This has the advantage of excellent rejection of out of band signals, but increases the noise figure (NF) of the system slightly. A higher noise figure means the ADS-B signal will end up being weaker, resulting in less range and reports. However, the FlightAware 1090 MHz filter has low insertion losses and should only increase the NF by 1-2 dB.

The Prostick Plus on the other hand uses a SAW filter positioned after the LNA. SAW filters at 1090 MHz typically have an insertion loss of anywhere between 2-3 dB’s. But since it is placed after the LNA the losses are almost completely eliminated by the gain from the LNA and thus the total NF remains low. The attenuation of the SAW filter is less, but it has a smaller pass band. The small pass band may be useful for people who live near an airport and suffer issues with interference from the 1030 MHz interrogation pulses or from GSM at 950 MHz.

In theory, the Prostick + Filter should operate better in environments with very strong out of band signals (any signal outside of 1090 MHz). And the Prostick Plus should operate better in environments with weaker out of band signals. The theory is that since the LNA is placed first in the signal chain on the Prostick Plus, it is more susceptible to overloading from the strong signals as it has no protection from a filter. The LNA used in both Prosticks is a SKY7150, which has a very high OIP3 rating. High OIP3 means that its performance in the presence of strong signals is excellent, and it will not overload so easily. However, even a very high OIP3 rated LNA cannot withstand the strong broadcast signals in some locations.

The Prostick Plus also has some other enhancements like a TCXO. ADS-B is very tolerant to frequency drift, so a TCXO won’t really improve decoding performance, but the cost of a 28.8 MHz TCXO purchased in bulk is under $1 USD, so they may have decided to add it anyway. They appear to also be using TCXO’s on the new production batches of the Prostick as well. The Plus also only draws 300 mA of current compared to the Prostick which draws 330mA. This may be due to the removal of the LED (Although the new batches of the Prostick might also have the LED removed as they advertise a power draw of 300 mA.) On the image of the PCBs below you can see the difference. The SAW filter is just underneath where the LED used to be.

Again, as we mentioned in our previous review of the Prostick it is a bit odd that the 39 dB OIP3 SKY7150 only appears to be drawing 60 mA, when it should be drawing 100 mA. The lower current usage is probably because they run it from 3.3V instead of 5V. The lower current use probably means that the OIP3 rating is reduced slightly by ~5 dBs.

The Prostick Plus and Prostick PCBs
The Prostick Plus and Prostick PCBs

Real World Testing

Here we test the Prostick and Prostick Plus in a signal environment with lots of strong interfering BCFM, DVB-T and GSM signals around. We’ve seen reports on the FlightAware forums that some users have seen improved performance with the Prostick Plus, whilst others have seen dismal or reduced performance. In these tests and review we are able to show when each stick will perform at its best. We do not test the Prostick without the filter, as without the filter we are unable to receive any ADS-B messages at all due to overloading.

Test 1: Flight Aware ADS-B Antenna

First we set up a test using the FlightAware ADS-B antenna, a 2-way signal splitter and the Prostick Plus and Prostick + Filter. We used Modesdeco2 as the ADS-B software, and ran the test for 45 minutes.

Contacts2
Coverge_FAAnt2
Messages_FAAnt_2
VRS_Compare

The results show that the Prostick Plus edges ahead of the Prostick + Filter by a small amount. It seems that the 1-2 dB loss in the external filter does not contribute to a huge reduction in ADS-B messaging, but the results do show that the Prostick Plus will give you better results in an environment with favorable reception conditions.

In this test we used the excellent FlightAware ADS-B antenna. This antenna is tuned specifically to 1090 MHz, and performs some rejection of the out of band signals. This rejection is enough to allow the Prostick Plus to work well in our test area without overloading.

In the image slider below we first checked ADS-B reception in SDR#, to see if there was any noticeable visual difference. The reception seemed identical. In the remaining images we checked to see how the reception was on out of band signals with the two units. In these tests we want the out of band signals to be low, so smaller signals are better. The Prostick Plus filters our out band signals significantly less, which can be a reason for increased overload. But the amount of filtering performed by the Plus was sufficient together with this 1090 MHz tuned antenna to not cause any overload at max gain.

ADS-B Comparison

ADS-B Comparison

BCFM

BCFM

152 MHz

152 MHz

858 MHz

858 MHz

Test 2: Discone Antenna

In test 2 we show what can happen if the out of band signals going into the Prosticks are really strong. This could especially happen if you are using a wideband antenna that is not specifically tuned to 1090 MHz, or if the out of band signals in your area are exceptionally strong (living near a transmission tower for example). In this test we used the same setup as in test 1, but used a wideband discone as the antenna instead. This means that the natural out of band signal filtering from the FlightAware antenna is not present anymore, and thus out of band signals come into the dongle much stronger.

Contacts_Discone
Coverge_Discone
Messages_Discone

Here we found that the Prostick Plus produced dismal results. The out of band signals were too strong for the LNA to handle, thus causing overload and significant desensitization of the ADS-B signals. The messages received by the Prostick + Filter was significantly higher. 

In the SDR# screenshots below we can clearly see that the Prostick Plus has very poor ADS-B reception at 1090 MHz with this antenna. The noise floor is much higher due to desensitization and overload from broadcast FM and DVB-T signals. Reducing the gain on the RTL-SDR does not help a lot, since most of the overload occurs in the first stage SKY7150 LNA. This can also be seen in the amount of signal overload that is present when tuned to the broadcast FM and other bands in SDR#.

ADS-B Comparison

ADS-B Comparison

1090 MHz Gain Reduced

1090 MHz Gain Reduced

BCFM

BCFM

BCFM Gain Reduced

BCFM Gain Reduced

152 MHz

152 MHz

415 Mhz

415 Mhz

858 MHz

858 MHz

Conclusions

The Prostick and Prostick Plus dongles are both excellent low cost ADS-B receivers. If you want to set up a permanent ADS-B monitoring station they are highly recommended. 

So what are the lessons learned from these tests?

  1. If you live in an environment with extremely strong out of band signals you’ll need to place the filter first. So in this case use the Prostick + external filter combination (or Prostick Plus + external Filter).
  2. Otherwise use the Prostick Plus for slightly better performance and lower cost.
  3. To reduce the possibility of overload with the Prostick Plus use an antenna tuned to 1090 MHz.

The table below summarizes the recommendations again.

 

Antenna -> LNA -> Filter
(Prostick Plus)

Antenna -> Filter -> LNA
(Prostick + FA Filter)
Advantages

Noise figure (NF) is dominated by the LNA, thus this method gives minimum NF.

Losses in filter overcome by LNA gain.

LNA will not be susceptible to overloading from out of band signals.

Disadvantages

The LNA can overload from out of band signals since it is not protected by a filter.

The insertion loss (IL) of the filter directly adds to the noise figure (NF). For example a 2 dB IL filter will add 2 dB to the system NF. This may result in a few dB’s lower SNR.

When to use Use this method if you do not have strong out of band signals in your area and/or if you have an LNA with a high OIP3 rating, like with the SKY7150 LNA which is used on the Prostick’s. Use this method if you have very strong out of band signals in your area.

For most people the Prostick Plus should work fine and be the better choice. Also rest assured that if you purchase a Prostick Plus and find that it overloads in your environment, you still always have the option of placing an external filter in front of it. Then you’ll practically have the same performance as with the standard Prostick + Filter combination. A Prostick Plus + External Filter combination may even be more beneficial for users in very very strong signal environments.

Also remember that the Prostick’s are designed to be placed as close to the antenna as possible, without the use of coax cable. You can use USB extension cables, or run the Prostick on a remote Raspberry Pi computing unit to achieve this. If you want to run coax between the antenna and Prostick, you will see heavily reduced performance due to the losses in the coax cable. In this situation you should instead place an LNA like the LNA4ALL or Uputronics ADS-B LNA by the antenna, and use a bias tee to power it.

FlightAware Prostick vs FlightAware Prostick Plus: Review

Recently the FlightAware Prostick Plus was released. The Prostick is a modified RTL-SDR with a LNA built into the dongle. It is optimized for ADS-B reception and works very well due to the low noise figure of the SKY7150 LNA which is used as the first stage LNA. However, due to the increased gain from the LNA it can easily overload from strong out of band signals, such as broadcast FM, DAB, DVB-T and GSM. To eliminate this problem FlightAware recommend using their 1090 MHz filter in front of the dongle. 

The FlightAware Prostick Plus is the same as the Prostick, but the Plus also incorporates a 1090 MHz SAW filter into the dongle itself. The overall cost is about $15.95 USD cheaper than buying the Prostick + Filter combination. See below for a tabulated comparison between the two units.

  FlightAware Prostick + Filter FlightAware Prostick Plus
Price

USA: $16.95 + $19.95 = $36.9 (Buy Prostick) (Buy Filter)

Worldwide: $48.99 + $18 Shipping = $66.99
(Buy Prostick + Filter)

USA: $20.95
(Buy Prostick Plus)

Worldwide: $29.99 + $12 Shipping = $41.99
(Buy Prostick Plus)

LNA + Filter Arrangement Filter -> SKY7150 LNA SKY7150 LNA -> Filter
Filter Specs Type: LC
Passband:
980 – 1150 MHz
Insertion Loss: 1.65 dB
Attenuation: 40 – 50 dB
Type: SAW
Passband:
1,075 MHz – 1,105 MHz
Insertion loss: 2.3 dB
Attenuation: 30 dB 
TCXO Old batches NO.
New batches YES.
YES
Current Draw 330 mA 300 mA
The new Pro Stick Plus RTL-SDR based ADS-B Receiver from FlightAware.
The new Pro Stick Plus RTL-SDR based ADS-B Receiver from FlightAware.

The first thing we notice is that the filter arrangement between the two units is reversed. On the Prostick the filter is external and must be placed before the LNA. This has the advantage of excellent rejection of out of band signals, but increases the noise figure (NF) of the system slightly. A higher noise figure means the ADS-B signal will end up being weaker, resulting in less range and reports. However, the FlightAware 1090 MHz filter has low insertion losses and should only increase the NF by 1-2 dB.

The Prostick Plus on the other hand uses a SAW filter positioned after the LNA. SAW filters at 1090 MHz typically have an insertion loss of anywhere between 2-3 dB’s. But since it is placed after the LNA the losses are almost completely eliminated by the gain from the LNA and thus the total NF remains low. The attenuation of the SAW filter is less, but it has a smaller pass band. The small pass band may be useful for people who live near an airport and suffer issues with interference from the 1030 MHz interrogation pulses or from GSM at 950 MHz.

In theory, the Prostick + Filter should operate better in environments with very strong out of band signals (any signal outside of 1090 MHz). And the Prostick Plus should operate better in environments with weaker out of band signals. The theory is that since the LNA is placed first in the signal chain on the Prostick Plus, it is more susceptible to overloading from the strong signals as it has no protection from a filter. The LNA used in both Prosticks is a SKY7150, which has a very high OIP3 rating. High OIP3 means that its performance in the presence of strong signals is excellent, and it will not overload so easily. However, even a very high OIP3 rated LNA cannot withstand the strong broadcast signals in some locations.

The Prostick Plus also has some other enhancements like a TCXO. ADS-B is very tolerant to frequency drift, so a TCXO won’t really improve decoding performance, but the cost of a 28.8 MHz TCXO purchased in bulk is under $1 USD, so they may have decided to add it anyway. They appear to also be using TCXO’s on the new production batches of the Prostick as well. The Plus also only draws 300 mA of current compared to the Prostick which draws 330mA. This may be due to the removal of the LED (Although the new batches of the Prostick might also have the LED removed as they advertise a power draw of 300 mA.) On the image of the PCBs below you can see the difference. The SAW filter is just underneath where the LED used to be.

Again, as we mentioned in our previous review of the Prostick it is a bit odd that the 39 dB OIP3 SKY7150 only appears to be drawing 60 mA, when it should be drawing 100 mA. The lower current usage is probably because they run it from 3.3V instead of 5V. The lower current use probably means that the OIP3 rating is reduced slightly by ~5 dBs.

The Prostick Plus and Prostick PCBs
The Prostick Plus and Prostick PCBs

Real World Testing

Here we test the Prostick and Prostick Plus in a signal environment with lots of strong interfering BCFM, DVB-T and GSM signals around. We’ve seen reports on the FlightAware forums that some users have seen improved performance with the Prostick Plus, whilst others have seen dismal or reduced performance. In these tests and review we are able to show when each stick will perform at its best. We do not test the Prostick without the filter, as without the filter we are unable to receive any ADS-B messages at all due to overloading.

Test 1: Flight Aware ADS-B Antenna

First we set up a test using the FlightAware ADS-B antenna, a 2-way signal splitter and the Prostick Plus and Prostick + Filter. We used Modesdeco2 as the ADS-B software, and ran the test for 45 minutes.

Contacts2
Coverge_FAAnt2
Messages_FAAnt_2
VRS_Compare

The results show that the Prostick Plus edges ahead of the Prostick + Filter by a small amount. It seems that the 1-2 dB loss in the external filter does not contribute to a huge reduction in ADS-B messaging, but the results do show that the Prostick Plus will give you better results in an environment with favorable reception conditions.

In this test we used the excellent FlightAware ADS-B antenna. This antenna is tuned specifically to 1090 MHz, and performs some rejection of the out of band signals. This rejection is enough to allow the Prostick Plus to work well in our test area without overloading.

In the image slider below we first checked ADS-B reception in SDR#, to see if there was any noticeable visual difference. The reception seemed identical. In the remaining images we checked to see how the reception was on out of band signals with the two units. In these tests we want the out of band signals to be low, so smaller signals are better. The Prostick Plus filters our out band signals significantly less, which can be a reason for increased overload. But the amount of filtering performed by the Plus was sufficient together with this 1090 MHz tuned antenna to not cause any overload at max gain.

ADS-B Comparison

ADS-B Comparison

BCFM

BCFM

152 MHz

152 MHz

858 MHz

858 MHz

Test 2: Discone Antenna

In test 2 we show what can happen if the out of band signals going into the Prosticks are really strong. This could especially happen if you are using a wideband antenna that is not specifically tuned to 1090 MHz, or if the out of band signals in your area are exceptionally strong (living near a transmission tower for example). In this test we used the same setup as in test 1, but used a wideband discone as the antenna instead. This means that the natural out of band signal filtering from the FlightAware antenna is not present anymore, and thus out of band signals come into the dongle much stronger.

Contacts_Discone
Coverge_Discone
Messages_Discone

Here we found that the Prostick Plus produced dismal results. The out of band signals were too strong for the LNA to handle, thus causing overload and significant desensitization of the ADS-B signals. The messages received by the Prostick + Filter was significantly higher. 

In the SDR# screenshots below we can clearly see that the Prostick Plus has very poor ADS-B reception at 1090 MHz with this antenna. The noise floor is much higher due to desensitization and overload from broadcast FM and DVB-T signals. Reducing the gain on the RTL-SDR does not help a lot, since most of the overload occurs in the first stage SKY7150 LNA. This can also be seen in the amount of signal overload that is present when tuned to the broadcast FM and other bands in SDR#.

ADS-B Comparison

ADS-B Comparison

1090 MHz Gain Reduced

1090 MHz Gain Reduced

BCFM

BCFM

BCFM Gain Reduced

BCFM Gain Reduced

152 MHz

152 MHz

415 Mhz

415 Mhz

858 MHz

858 MHz

Conclusions

The Prostick and Prostick Plus dongles are both excellent low cost ADS-B receivers. If you want to set up a permanent ADS-B monitoring station they are highly recommended. 

So what are the lessons learned from these tests?

  1. If you live in an environment with extremely strong out of band signals you’ll need to place the filter first. So in this case use the Prostick + external filter combination (or Prostick Plus + external Filter).
  2. Otherwise use the Prostick Plus for slightly better performance and lower cost.
  3. To reduce the possibility of overload with the Prostick Plus use an antenna tuned to 1090 MHz.

The table below summarizes the recommendations again.

 

Antenna -> LNA -> Filter
(Prostick Plus)

Antenna -> Filter -> LNA
(Prostick + FA Filter)
Advantages

Noise figure (NF) is dominated by the LNA, thus this method gives minimum NF.

Losses in filter overcome by LNA gain.

LNA will not be susceptible to overloading from out of band signals.

Disadvantages

The LNA can overload from out of band signals since it is not protected by a filter.

The insertion loss (IL) of the filter directly adds to the noise figure (NF). For example a 2 dB IL filter will add 2 dB to the system NF. This may result in a few dB’s lower SNR.

When to use Use this method if you do not have strong out of band signals in your area and/or if you have an LNA with a high OIP3 rating, like with the SKY7150 LNA which is used on the Prostick’s. Use this method if you have very strong out of band signals in your area.

For most people the Prostick Plus should work fine and be the better choice. Also rest assured that if you purchase a Prostick Plus and find that it overloads in your environment, you still always have the option of placing an external filter in front of it. Then you’ll practically have the same performance as with the standard Prostick + Filter combination. A Prostick Plus + External Filter combination may even be more beneficial for users in very very strong signal environments.

Also remember that the Prostick’s are designed to be placed as close to the antenna as possible, without the use of coax cable. You can use USB extension cables, or run the Prostick on a remote Raspberry Pi computing unit to achieve this. If you want to run coax between the antenna and Prostick, you will see heavily reduced performance due to the losses in the coax cable. In this situation you should instead place an LNA like the LNA4ALL or Uputronics ADS-B LNA by the antenna, and use a bias tee to power it.

Running the Airspy ADSB decoder at full speed on a Raspberry Pi 2

Bob W9RAN recently wrote in to let us know about some developments he and Youssef have had with getting the Airspy to function at full speed on a Raspberry Pi 2 with ADS-B decoding. Bob and Youssef created the SpyVerter upconverter, and Youssef is the programmer of SDR# and the co-creator of the Airspy SDR. Bob writes the following:

Airspy is a high-performance SDR that streams 12 bit samples at 20 MSPS (real, not IQ) to a PC where the real processing is done. But 20 million samples per second uses a significant fraction of the bandwidth available with USB 2.0, and has made apparent the weaknesses in USB subsytems on a number of PCs. So of course the natural assumption by “experts” has been that the Raspberry Pi 2 isn’t up to the task.

As we Pi fans know, the Pi 2 has a 900 Mhz 4-core ARM Cortex A7 CPU, and the key to performance is properly implemented code that can take full advantage of the processor architecture.

Youssef Touil, author of SDR# and creator of Airspy has done that, proving first that an optimized multithreaded version of his ADSB decoder would run on a 4-core Odroid that has more CPU power than the Pi 2. But today we have proven that not only can the Raspberry Pi 2 run the optimized ADSB decoder at full speed (20 million samples per second via USB), but that it even has enough horsepower left to run the Virtual Radar Server Google map display in the Pi’s Epiphany web browser!

For those not familiar, the map display is created by a program called Virtual Radar Server that runs on a PC and receives samples from the Pi over ethernet, and includes a web server that allows other computers (in my case, the Pi 2) to view the composite map display. (For more information about ADSB, see my article in QST for January 2014).

I’m really thrilled to be able to demonstrate that the Pi 2 has this
impressive capability! This makes it feasible to create inexpensive high performance ADSB receiving systems, and who knows what else?

Monitoring FBI Surveillance Aircraft with ADS-B and an RTL-SDR

After reading an article by the Washington Post about FBI surveillance aircraft spotted in the air after the West Balimore riots, John Wiseman decided to look for more information about these aircraft. Fortunately, John had on his hands a database of about 2 months of ADS-B data that was collected by his continuously running RTL-SDR + BeagleBone Black ADS-B decoder set up.

From reports on the internet John found out that FBI aircraft squawked with 4414 or 4415 codes, and used call signs like JENNA or JENA. With this information John decided to take a look through his ADS-B logs to see if if he could find anything similar. Out of 15,000 aircraft he had tracked, he found 9 aircraft in his logs that matched the criteria, and saw that they did exhibit suspicious behaviour such as circling over LA for hours at a time. Then by looking up their FAA records of the tail numbers of the suspicious aircraft, he was able to discover that these aircraft where licensed to companies with names like NG Research, OBR Leasing, Aerographics Inc. and PXW Services which are suspected Department of Justice front companies. John also writes:

If you Google the tail numbers of aircraft registered to those companies, you start to find forum and mailing list posts (often at sites that tilt toward paranoid/conspiracy/right wing, but not always) with people discussing these specific tail numbers and linking them to the FBI. Some of the supposed evidence includes details of radio communications that people have heard, e.g. talking about “being on station” or using callsigns that start with JENNA, JENA or ROSS, which are supposedly used by the FBI. Other posts claim that DOJ/FBI surveillance aircraft often squawk 4414 or 4415 on their transponders.

An article from the startribune talks about the surveillance planes and says:

The planes use “persistent wide-area surveillance” to photograph large areas for hours at a time, Stanley said. The captured images allow authorities to go back in time, if necessary, to trace pedestrians and vehicles who come to their attention.

Other devices known as “dirtboxes,” “Stingrays” or “IMSI catchers” can capture cellphone data. Stanley said it’s still unclear what technologies have been used in the surveillance flights.

 

Possible FBI Surviellance Aircraft Path from flightradar24.com
Possible FBI Surviellance Aircraft Path from flightradar24.com

New ADS-B Decoder for the Airspy Released

Youssef, the main programmer of SDR# and creator of the Airspy software defined radio has just released a beta version of an ADS-B decoder for the Airspy. The software is called “ADSB Spy” and is similar in operation to ADSB# which is used with the RTL-SDR dongle. The increased sensitivity and lower noise floor of the Airspy should help ADS-B enthusiasts get longer ranges and more aircraft on their screen.

The beta version of ADSB Spy can be downloaded at http://www.airspy.com/downloads/adsbspy.zip.

ADSB Spy - An ADS-B decoder for the Airspy
ADSB Spy – An ADS-B decoder for the Airspy

Interest Check for an ADS-B Folded Monopole Antenna

Adam, manufacturer of the LNA4ALL and LNA4HF is putting out an interest check for an ADS-B folded monopole antenna. The antenna can efficiently cover the 1030 MHz to 1090 MHz frequencies that are used by ADS-B.

The major advantage to Adams antenna is that it uses a DC grounded design, eliminating static build up problems that can potentially fry your LNA or RTL-SDR dongle.

If there is sufficient interest, Adam will sell the antenna for 20 Euros.

ADS-B Folded Monopole Antenna
ADS-B Folded Monopole Antenna

The BIG List of RTL-SDR Supported Software

There are now dozens of software defined radio packages that support the ultra cheap RTL-SDR. On this page we will attempt to list, categorize and provide a brief overview of each software program. We categorize the programs into general purpose software, single purpose software, research software and software compatible with audio piping.

If you know of a program that is missing please leave a comment in the comments section at the bottom of the page.

13/02/2014 – Added Sodira, gr-wmbus, rtlsdr-waterfall, QTRadio, multimon, sdrangelove, lte-scanner, rtl_tcp, rtl_sdr_FS20_decoder.
17/02/2014 – Updated the Linrad description.
28/04/2014 – Added Modesdeco and Trunk88.
30/05/2014 – Added RTL Panorama, RTL SDR Panoramic Spectrum Analyzer, Chrome Radio Receiver, SeeDeR, DAB Player, RTL SDR Installer, PD/Max Wrapper, SDRWeather, LTR Analyzer, softEOT/softDPU and ScanEyes.
26/07/2014 – Added PiAware, OOK-Decoder, rtl_fm_python, rtl_power heatmap viewer, RTL Bridge, threejs-spectrum, CANFI Software, PNAIS, FLARM Decoder, Xastir, RTLSDR-Airband, SDRTrunk.
13/11/2014 – Added Touchstone, RFAnalyzer, RTL1090 XHSI Interface, Parus Decoder, PlotRTL1090, LRPT Decoder.
05/02/2015 – Added rtl_tool_kit, CubicSDR, OregonWeather, FreqWatch.
15/04/2015 – Added ADSBox, YouSDR, FlightAware Flight Feeder, Frequensea, Track your flight EUROPE, QSpectrumAnalyzer, Doppler & Demod, Redsea, rtl_heatmap, gr-gsm, driveby, SDRecord.
23/12/2015 – Added Remote rtl_udp, AISRec, dump978, AISDeco2, SDRrecorder, OpenWebRX, dsame, RTL-Widespectrum, rtl_ais, rtl_gopow, ham2mon, rtl_ais_android, inmarsatdecoder, spektrum, qtcsdr, rtl_power_fftw, JAERO, GNSS-SDRLIB, SVxLink.
8/09/2017 – Added inspectrum, gr-isdbt, telive, tetra-listener, gr-iridium, SDRuno, luaradio, rx_tools, kukuruku, chronolapse, cloud-sdr, natpos, d3-waterfall, SDRDue, gqrx-ghostbox, ships, rtlmic, tsl-sdr, universal radio hacker, dumpvdl2, re-dected, aerial-tv, questasdr, welle.io, spyserver, dspectrumgui, atcsmonitor, NRSC5 HD Radio Decoder, leandvb, imsi-catcher, block stream receiver, salamandra, deinvert, RS.

General Purpose RTL-SDR Software

We define general purpose SDR software as programs that allow the RTL-SDR to work like a normal wideband radio receiver.

SDR# (Windows) (Free)

SDR#
SDR#

SDR# (pronounced “SDR Sharp”) is the most popular free RTL-SDR compatible software in use at the moment.  It is relatively simple to use compared to other SDR software and has a simple set up procedure. We have a full overview of the installation procedure on our Quick Start Page. SDR# is designed to be use with the $199 Airspy SDR, but works just fine with the RTL-SDR.

SDR# is a simple to use program that also has some advanced features. It has a useful modular plugin type architecture, and many plugins have already been developed by third party developers. The basic SDR# download without any third party plugins includes a standard FFT display and waterfall, a frequency manager, recording plugin and a digital noise reduction plugin. SDR# also decodes RDS signals from broadcast FM.

HDSDR (Windows) (Free)

HDSDR
HDSDR

HDSDR is based on the old WinRAD SDR program. HDSDR supports the RTL-SDR through use of an ExtIO.dll module. To install HDSDR, download the program from the link on the main HDSDR page, then to use the RTL-SDR you will need to download the ExtIO_RTL2832.dll file an place it into the HDSDR folder. When opening HDSDR, select the newly copied ExtIO_RTL2832.dll. The other dlls that come with HDSDR will not work with the RTL-SDR, even though they have RTL-SDR in their filename. The official installation instructions can be found here.

Along with a FFT display and waterfall, HDSDR has some extra advanced features. Users will also find an Audio FFT and waterfall display on the bottom of the screen. The output audio can also be bandpass filtered by dragging the filter borders on the display. Bandpass filtering the audio can really help clean up a noisy signal. The audio processing also supports placing of notch filters either manually or automatically. There are also noise reduction and noise blanker features and an automatic frequency centering algorithm which will automatically center the signal, so you don’t need to click exactly in the center of a signal. Traditional ham radio users will also enjoy the S-units signal strength meter and the built in frequency manager.

SDR-RADIO.COM V2/V3 (Windows) (Free)

SDR-RADIO.COM V2
SDR-RADIO.COM V2

SDR-RADIO.COM V2 and the newer V3 is a popular SDR program with many advanced features. As such is it a fair amount more difficult to learn and use compared to SDR# and HDSDR. Be sure you install version 2 and not V1.5 as only V2 has RTL-SDR support.

Once sdr-radio is installed, to get it working with the RTL-SDR you will need to compile or download three .dll files (SDRSourceRTL2832U.dll, rtlsdr.dll and libusb-1.0.dll) and place them into the sdr-radio folder. To compile your own dlls see the instructions here, otherwise download the dlls directly from the bottom of this link. If the dlls were placed in the correct folder you will be able to add your RTL-SDR as a receiver by clicking on the +Definitions button, and then finding and adding the RTL SDR (USB) option under the search drop down menu.

Like HDSDR, not only does sdr-radio have a RF FFT signal and waterfall display, but also an optional audio spectrum FFT and waterfall display. Built in are also several DSP features like a noise blanker, noise reduction filter, notch filter and squelch options. The EMNS noise reduction filter is particularly good at automatically cleaning up and clarifying voice signals.

To add to the feature list, sdr-radio also has built in PSK, RTTY and RDS decoders, and also comes with a satellite tracker. Furthermore, sdr-radio V2 (not V3 yet) has an excellent remote server which will allow you to easily set up and connect to a remote RTL-SDR server over a network or the internet. Finally, sdr-radio is capable of listening to up to 6 signals in the same chunk of visible spectrum at a time.

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ADS-B Virtual Radar RTL-SDR Tutorial in the ARRL QST Magazine

The American Radio Relay League (ARRL) a.k.a The American National Association for Amateur Radio has put online a freely available ADS-B tutorial featured in their monthly QST magazine, written by Robert Nichols, W9RAN. The tutorial focuses on using an R820T RTL-SDR dongle to receive ADS-B signals, and then using computer software to decode the signals and create a virtual aircraft radar.

ADS-B is a protocol used by most modern aircraft to broadcast their position and altitude which is determined via GPS. ADS-B is intended to supplement and eventually replace traditional radar.

In this ADS-B tutorial, they show how to create a weatherproofed 1090 MHz collinear antenna from RG-6/U coax and PVC pipe and how to use the ADSB# and virtual radar server software to decode and visualize aircraft positions, like a radar.

If interested, we also have an ADS-B virtual radar tutorial that can be found here.

ADS-B Virtual Air Radar Tutorial by the ARRL
ADS-B Virtual Air Radar Tutorial by the ARRL

In Car ADS-B with a Raspberry Pi and RTL-SDR

Over on YouTube user adsbrus shows us his project which is an in car ADS-B aircraft tracker using a Raspberry Pi mini computer and an RTL-SDR. The system uses an LCD screen mounted where the car radio usually is to show aircraft identifier, altitude, and speed information in text.