This information was kindly supplied by Tim Plumridge - see this Yahoo group message - many thanks, Tim.
For full details of exactly how Mlat works read the Multilateration tutorial found by doing a search in the Help section of Plane Plotter (PP). There follows a summary of the basics required in setting it up, which should be read in conjunction with the tutorial. There are 2 options as to how to use Mlat:-
1. Become a Ground Station and get Master User Mlat for free.
2. Obtain a 21 day Mlat trial after which you can pay €12 to continue using it as a Master user.
What does Mlat look like? See the blue hyperbolae in John Locker's animation here.
Accurate time setting on your PC is required before you are allowed to run Mlat - be sure to install the NTP software. Your home location is not made available outside the internals of the shared server - the public information is deliberately degraded to about 5km to ensure your privacy. There is information on accurate time here, and now some notes from John Locker about determining your home location:
To check your location, go to multimap.com. Put in your exact home address, press the Aerial view button to the top left of the map, make sure that the circle is on the location of your antenna. If not double-click on your correct location to put the red circle where it should be. Look to the bottom right (you may need to scroll the Web browser) and in brackets you'll see your location in decimal degrees - something like Lat: 55:57:04N (55.95115) and Lon: 3:12:09W (-3.20251). Copy and past those co-ordinates into your PP Home Location box with N S E or W in front of the figures as appropriate. For example: N55.95115 W3.20251 - don't use the other format of the data from MultiMap! Now press the test function.
This option requires you to be able to provide “raw data” on a regular basis (ideally 24/7) but for many users this is simply not possible or practical so as long as data is provided for reasonable amounts of time this is generally OK. Obviously the more Ground Stations there are up and running the better for the general PP community, especially in areas of limited coverage, as Mlat requires at least 3 Ground Stations (ideally more) to be successful.
To become a Ground Station you need to be running one of the Kinetic SBS-1 (or -1E etc.), The Mode-S Beast, or the microADSB receivers, or use a low-cost R820T/RTL2832U dongle with or without leads (e.g. one of these from CosyCave) with the dump1090 for Windows software. The dongle with the dump1090 software (e.g. for the Raspberry Pi) is also available for lower-powered 24 x 7 operation. Unfortunately the data from RadarBox cannot be processed. You can also use the PlaneGadget Radar (no longer available).
To get started, then ...
Ensure that in BaseStation, Settings, Location Manager, the active location is correctly specified. This is in decimal degrees, so if you were at Eros, Piccadilly Circus, London, that would be Longitude: -0.134540, Latitude: 51.509851. Note that longitudes west of Greenwich are specified as negative numbers. In Plane Plotter you would specify: N51.509851, W0.134540, and here the letters W and E are used to specify West and East of Greenwich. Plane Plotter will display your location as <degrees> and <decimal minutes>, whereas <decimal-degrees> are used in BaseStation.
Please be especially careful to specify your location in both Plane Plotter and BaseStation, and change it when you go portable!
i. Ensure both Base Station and Plane Plotter are both closed. (Steps ii and iii are no longer required with BaseStation 161)
iv. Start Base Station and confirm it is working properly.v. In BaseStation, in the Settings tab, in the Data Settings pop-up dialogue box, under Message Filtering, there is a check box labelled "Ignore Non ADS-B Mode-S Messages". Ensure this box is not checked. Later reports suggest that "Process Mode-S Air to Air Replies" must also be checked (from: Roger Tinembart).
vi. Open Plane Plotter and under Options, I/O settings ensure the "Raw data for Mlats" box is ticked with 9742 in the UDP/IP local port box.
vii. Start to run Plane Plotter
- the time remaining for this Mlat cycle. Counts down from 10 seconds. The (1) (2) etc. are the number of the Mlat cycle.
- the number of raw reports, which should increase quickly to start with, perhaps less so as the cycle progresses.
- the hex code for the aircraft of interest.
- a status report about the success or otherwise of generating the fix.
- the number of Ground Stations contributing data about this aircraft.
- the number of Hyper curves generated.
- the number of users contributing data which could be used to make the hyper curves (by being fortuitously paired with the same data from another user). The latter are the "Curve users" and that is the number that must be at least 3 for the problem to be soluble.
If for any reason you are unable to meet the criteria of becoming a Ground Station e.g. you are a RadarBox user, don’t have SBS or are simply unable to leave the computer on for long periods of time, then paying is the only option. Visit http://www.coaa.co.uk/mlat_request.php and continue clicking through to complete the process; this gives a 21 day trial after which you can chose to pay the annual €12 fee if you wish. Having done this, follow the above from step 6.
Q: My 21 days free Mlat are up and I was looking to see where I can pay the 12 Euros?
A: Visit http://www.coaa.co.uk/mlat_request.php
Q: I've found that page but I cant find anywhere to pay the money, only to request 21 day Mlat again. Is this the way to go, to re-apply and go through the questionnaire again?
A: Yes - that is why it states on the button you have to click "Request free 21 day Master User free trial or extend Master User Status".
Q: Do I get to enjoy the same facilities if I pay rather than being an Mlat data provider?
A: Yes, you can use Mlat just as an Mlat data provider would.
Once your payment is received and processed, you should automatically become defined as a Master User. No further action is required.
Since Autumn 2010, the PlaneGadget-Radar receiver (no longer available) has also been able to provide data for the Mlat service. There was a PDF guide (no longer available) on the Plane Gadget Web site. Version 2.2 or later of the unit is required, and the full version of the Plane Plotter software.
Bob Fernandes writes:
I have Windows 7 64bit Ultimate and this is what I did. (Note that these steps are not required with Base Station 1.2.3.159 or later).
Peter Stonebridge writes:
When first loading BaseStation onto the Windows 7, 64 bit machine it wouldn't run because of a "missing .dll". It was FTD2XX.dll causing the trouble, cannot tell you where I got it, I just did a web search and this site popped up with all sorts of stuff and a free download of FTD2XX.dll. [Sounds dubious, use only well-known sources - ed.] Obviously it wasn't quite compatible with Windows 7, 64 bit, although it claimed to be. Also BaseStation ran fine until I tried to combine Ethernetovich with it and the rest is past history!
This morning I went to www.ftdichip.com and downloaded exactly the same named file and it obviously works fine as I am now an Mlat approved user.
If you have more details than these, please get in touch so that they can be added to the Wiki.
The settings you need in the Network tab of Multi-EM are:
SBS-1 Ethernet Module
Host 192.168.2.223 (Default Module IP)
Port: 20060
This Multi-EM interface
Host: This is the IP Address of your computer
Port: 20060
Local BaseStation installation points to
Multi EM 127.0.0.1:20060
Start-up order:
Start Multi-EM first
BaseStation second
Ethernetovitch third
Plane Plotter fourth
Milan wrote the following in this Yahoo group message.
I also have setup via the Ethernet port. My SBS is connected via the internet to a location about 5 miles away (on a hill). On the remote site I have put the SBS-er on the same IP as the local network of that location (192.68.11.170). I have then configured the router to port forward Port: 10001 to 192.168.11.170.
Once this is done, you can connect to the SBS via the Internet by going into BaseStation and "Hardware settings" and enter in the PUBLIC IP address of the REMOTE site plus port 10001. You will need a static IP address go to www.whatismyip.com to find put your IP. If you don't have a static IP then get one free from http://www.no-ip.com. If anyone needs settings etc I can allow remote access to my machine via RDP to see the settings for Mlat, Multi-EM, Boris Ethernet etc. I took me a while to figure it all out also.
Also in this message: For SBS-1 and PP with MLAT to work you need to install Multi EM, configure it (Radarspotters have a great tutorial) and then run BaseStation, start the Boris Ethernetvoich application and then Plane Plotter. Your BaseStation hardware settings will point towards the IP address that Multi EM is on and port 20060 (usually).
If you have a common model of router you may be able to find information about setting up the box in the Plane Plotter Groups.io Files Area. If not, read on about port forwarding...
Once you have your router set correctly, do remember to backup your router settings! See you router instructions for how to do this, as it will be different on various routers.
There is information on some specific routers here.
You may find the information here helpful about port forwarding. In particular, for any given router you can start at the URL below, and then follow the steps for your particular router.
http://www.portforward.com/english/applications/port_forwarding/Piolet/Pioletindex.htm
Steps:
If you get a lot of Mlat packets coming into your PC it is possible that the router will think your PC is under attack, and the router may close the path, resulting in very few Mlat responses and hence no Mlat positions. In that case, you will need to dig out your router manual and disable the D.o.S. (Denial of Service) function. Some PC security software may also need configuring to disable the D.o.S. function. As Plane Plotter will be getting apparently unsolicited packets from the Internet, your Windows firewall software may need to be set to allow this - for example: "Enable Incoming" in the Windows firewall, or "Act as a server" in Zone Alarm.
Rather than relying on the IP address which your router automatically assigns to your PC using DHCP, consider moving to fixed computer IPs - a static IP address, or using the Address Reservation feature of your router to tie a particular IP address to the MAC (Hardware) address of your PC - see here. How to find the MAC address of your PC's network card - see here. For some more information - see: http://portforward.com/networking/staticip.htm This will prevent the confusing and frustrating problem of Mlat working one day but not the next.
"Marijn 'The Guide' de Gids" writes:
Router Port Forwarding can be realised by using UPNP. Plane Plotter makes a batch file upnpmaster.bat in the Plane Plotter directory.
Prerequisites:
* Router must support UPNP (and have it enabled)
* Run upnpmaster.bat
I know UPNP is also a possible security hole but most 'home' routers have it enabled. I use it over here because I have DHCP enabled on my 'SBS server' and unfortunately it's not possible to reserve DHCP addresses in the router.
Yes! Nic Storey has created another in his popular video series entitled: Ground Station Setup
The Beast and SBS receivers have two important advantages over anything based on a dongle. Firstly the receiver is specifically designed for 1090 MHz with appropriate filtering etc. so outperforms any dongle based receiver. Secondly the decoding of the Mode-S data stream is done in dedicated hardware/firmware whereas all of the dongle-based solutions rely on the PC to perform the demodulation and decoding. The result is that the message rate on the dedicated receivers massively exceeds the message rate from a dongle-based solution. For normal use, especially where range is not an issue, this may not be significant, but for multilateration, you will remember from the tutorial that you studied, that it relies on timing pairs of messages (one with position and one unknown) received at two Ground Stations. If a dongle based solution is only delivering a fraction of the incoming messages, then the chances of such coincidences occurring is dramatically reduced so the success rate for Mlats is much lower if the Ground Station are dongle-based. In addition to this, the raw data time tags from the SBS1 are at 20MHz and from the Beast are at 12MHz. Those from dongle-based solutions are only at 2MHz which corresponds to a spatial resolution of 150 metres but the geometry of the hyperbolae is such that this can introduce an error in aircraft position of ten times that value so in general fixes based on dongle-receivers are much less accurate.
Of course, the low capital cost and the low running costs of an Raspberry Pi dongle-based Ground Station means that many more such Ground Station can be deployed, which might make up for the reduced performance and in any case "half a loaf is better than no bread". However, we would always urge those who are able to operate a Ground Station based on a dedicated receiver, not to switch to a dongle-based receiver unless it is imperative.
(Information from Bev's Yahoo post - URL: https://groups.yahoo.com/neo/groups/planeplotter/conversations/messages/130921)
A recent receiver which is a similar size to the RTL-dongle and can work with both the Raspberry Pi and Windows computers is the Airspy Mini. Because of its higher sampling rate if provides much more accurate Mlat data. It costs just over £/$/€ 100. The larger Airspy is also suitable. See: https://groups.yahoo.com/neo/groups/planeplotter/conversations/messages/131152
Check out the Mlat Troubleshooting Guide
There is a self-help group you can join for Mlat setup here: https://groups.io/g/planeplotter/
- announcement of version 5.4.5.3: http://groups.yahoo.com/group/planeplotter/message/28866
- chart requirements: http://groups.yahoo.com/group/planeplotter/message/29459
Assuming that you are a Master User, then checking the Auto Mlat option in Options, I/O settings means that whenever Plane Plotter is idle (no user interaction for some time), every minute or so it will attempt to Mlat any position-less aircraft in the list that have sufficient Ground Stations in the sharer list. Unlike manual Mlats, the progress is shown in the status bar and not in a pop up progress window.
See: Message Types