OK, so where are all the Flybe aircraft ??? (Radarbox nr Exeter, Devon)

[tarbat]

What is the accuracy of MLAT (NM) and how often is it updated?

I'm no expert, but my experience is that MLAT in Planeplotter can range from pretty accurate (within 10 miles), to very innaccurate.  In fact, my first MLAT'd aircraft jumped from the west to the east coast of Scotland between successive positions.  As the PP MLAT help states "It is the responsibility of the user to assess the curves on the chart to determine whether or not to be confident of the least-squares fix that PlanePlotter derives for the wanted aircraft."

And, my understand is that the MLAT'd position is calculated every 2 minutes, based on data gathered over the previous minute.

It's still a useful facility to get a rough idea of the position of an aircraft.  Two examples, although these do illustrate some of the positional inaccuracies that you get with MLAT:
 

EDIT: There's an excellent description in the PP help file about MLAT.  The section on "Position Errors" stretches to five paragraphs, and hopefully sets a realistic level of expectation that you can expect from multilateration.

[bratters]

Tarbat, would it be true to say that the more contributors, the more accurate and more regular the plotting would be?

[tarbat]

Tarbat, would it be true to say that the more contributors, the more accurate and more regular the plotting would be?

I'm no expert, but I would guess that the more Ground Stations there are, the more accurate the position.  To get ANY chance at a position, you need at least 3 Ground Stations that can all see the same non-ADS/B aircraft, as well as all see one other ADS/B aircraft, at the same time.  This requirement means that approx. 95% of my attempts at getting an MLAT fix fail :(

I would also guess there is a limit to how accurate the position can be calculated, based on the accuracy of the timing from an SBS-1, accuracy of the Ground Station map coordinates, accuracy of PC clocks, etc.

AFAIK, the update rate of one calculation every 2 minutes is fixed regardless of the number of Ground Stations.

[raflec]

"As to what aircraft can you see before you buy it...well thats what the free trial will hopefully tell you.  I get all sorts from light aircraft, to regional airlines (such as Flybe), many commercial jets which just aren't fitted with ADS-B  (eg Embraer ) to military aircraft."

Hi Jon, But with the free trial you cannot subscribe to MLAT, because it asks you for your email and product code. i.e you have to first purchase PP for £25 Unless I am doing something wrong.
Graham








[/quote]

[DaveReid]

"As to what aircraft can you see before you buy it...well thats what the free trial will hopefully tell you.  I get all sorts from light aircraft, to regional airlines (such as Flybe), many commercial jets which just aren't fitted with ADS-B  (eg Embraer ) to military aircraft."

Hi Jon, But with the free trial you cannot subscribe to MLAT, because it asks you for your email and product code. i.e you have to first purchase PP for £25 Unless I am doing something wrong.

Even the time-limited trial version of PP will enable you to see:

1.  what non-ADS-B aircraft are available on the network

2.  which other sharer(s) are picking up the same aircraft

3.  where said sharers are located in relation to you

4.  which of these sharers, if any, are MLat ground stations

Combined, that information should be sufficient for you to make an informed decision about whether MLat via PP would be viable in your neck of the woods.

There is even a free add-on utility called MyCircles which will do most of the above automatically, and should work with PP in evaluation mode, although obviously full MLat is much more accurate.

[AirNav Development]

"I'm no expert, but my experience is that MLAT in Planeplotter can range from pretty accurate (within 10 miles), to very innaccurate."

Despite 95% of the forum members being enthusiasts RadarBox is being used by many professional clients who can't afford to access data that "sometimes" can be unreliable and other times be correct. This explains why we haven't included MLAT on RadarBox now. Anyway RadarBox is well known for having everything inside its software: no need for external addons at all (the application is still 100% compatible with port 30003 output).

So it is obvious that MLAT will be included in the application too. Taking in account we have most of the time 5x to 10x more network users than PP it is easy to understand that the result of this implementation will be more accurate with our software.

Stby on this one. As usual we will always innovate so having a RadarBox receiver guarantees that you are "in good hands".

[DaveReid]

Despite 95% of the forum members being enthusiasts RadarBox is being used by many professional clients who can't afford to access data that "sometimes" can be unreliable and other times be correct. This explains why we haven't included MLAT on RadarBox now. Anyway RadarBox is well known for having everything inside its software: no need for external addons at all (the application is still 100% compatible with port 30003 output).

So it is obvious that MLAT will be included in the application too. Taking in account we have most of the time 5x to 10x more network users than PP it is easy to understand that the result of this implementation will be more accurate with our software.

Good luck.

If you succeed in implementing a plug-and-play, out-of-the-box MLat solution for RadarBox users, then congratulations will be in order.

However I fear that, just as with RadarBox V3 and RB 3D, this will turn out to be yet another distraction from the more fundamental issue of fixing the database, which doesn't seem to have progressed at all.

Most users, not least your professional ones, will be pretty unimpressed when RadarBox MLats an aircraft and then displays details and photos for an entirely different airframe ...

[AirNav Development]

DaveReid: sincerely we are totally tired of reading your weekly complaints of database problems and we do believe that all forum readers should know what is behind this.

You have a company that wants to provide database information to AirNav Systems and you want to profit from this. We have more than one time informed you by email that we were not interested in such services and that if in the future we changed our position, we would contact you directly.

So there is no point in continuously playing the "database has problems" game with the objective of AirNav Systems paying you a fee to access the services you provide. As a company we are simply not interested in your paid solutions.

Hope this clarifies the information.

[ACW367]

Radarbox

Whilst a professional solution may not be within what you require at this time.  All we are asking as users is that the Navdata DB is brought up to date a little when 3D is released. I for one count the lack of an update as my biggest disappointment when 3.13 was released.  I do not consider that I require a rolls-royce standard, just a spring clean around the edges.

This could be looked at by a developer in spare time whilst waiting for programmes to run.  Or it could be done by a student/son of employee for a couple of weeks as a vacation job.

Even if the only work undertaken is to change non-ICAO codes that are currently throughout the released Navdata to the correct ICAO codes (we have posted the anomolies here enough times).

I have also used online production lists to review older fleets in the DB like B72* B732, DC9*, LJ23, C500 etc. For each type I have been able to delete around half the records as aircraft which are broken-up, PWFU or changed registration.  For example I have also removed the couple of hundred United Boeing 737s which have all been retired.

Additionally your server must contain 2-3000 codes of aircraft delivered over the last couple of years which do not appear on the Navdata DB3 which was released to us with version 3.13 and which we then had to reach back into your server to populate again.

All we are asking is that the NavData DB3 that is released with 3D is tidied up a little.  Put back in alphabetical order with correct ICAO codes. With some older aircraft that are long gone to thier maker manually stripped out, and some of the newly delivered airliners of major carriers added.  The airline list in the DB can also be compared to online versions of ICAO8585 to ensure defunct airlines are removed and correct IATA codes applied.  

There are enough online resources out there, surely someone in your company in thier spare moments or a vacation worker employed for a week or so could do at this little or no overall cost.  It would make a major difference to something that we your customers consider to be one the finer details of your great product.

Regards ACW

[AirNav Development]

ACW: thanks for your long post.

There are two situations here:
1- A problem with a very limited number of aircraft that might not be correctly updated on our database. As stated by our support many times this has been noted and is on our to-do list. This is what really matters here and it's still on the to-do list.

2- A user that constantly focuses on the same problem with hidden objectives. That situation is totally clarified now.

[ACW367]

Thank you for noting my points Airnav.  I would point out that in my limited editing of old aircraft and larger fleets like 727's and DC9s that have been shed by airlines. I came up with around 8000 aircraft that have been PWFU/Scrapped etc. That is slightly more than a very few aircraft, it is around 10% of your DB.  

[Fenris]

Airnav

Please can you add the ability to see what is missing in the database when the populate facility in MyLog is used?

I currently have 637 aircraft showing as requiring something to be updated but despite there being lots of server photo requests the number does not change on the next attempt, in fact it just gets bigger and bigger, it was well below 400 a couple of months ago.

I don't know how to improve this situation because I can't tell what is missing, a list of what the program considers in need of updating would be really useful.

Cheers!

[jannuh]

DaveReid: sincerely we are totally tired //   // you directly.

So there is no point in continuously playing the "database has problems" game with the objective of AirNav Systems paying you a fee to access the services you provide. As a company we are simply not interested in your paid solutions.

Hope this clarifies the information.

Haha, a very good one, AN is just  interested to get something for free (for instance our data) and sell it then for a "reasonable" price....

Yes AN users this is the joke of the day, a new gadget at AN forum!

[ACW367]

Airnav

Please can you add the ability to see what is missing in the database when the populate facility in MyLog is used?

I currently have 637 aircraft showing as requiring something to be updated but despite there being lots of server photo requests the number does not change on the next attempt, in fact it just gets bigger and bigger, it was well below 400 a couple of months ago.

I don't know how to improve this situation because I can't tell what is missing, a list of what the program considers in need of updating would be really useful.

Cheers!

Fenris
What the computer feels needs updating is any blank field.  Therefore if you list by all time and click on each column header, it will place those with blank values at the top.   These are the ones you now need to manually updatein your database explorer.

Since following users requests, Airnav stopped the server downloading the '...' in the type field and the 'untitled' in the airline field.  These are now populated by blanks, no matter how many times you reach back to the server.

Users requested this to ensure more accurate owner information could be manually input by them.  Airnav implemented as per the user requests.  

The onus is now on you to manually update the AT and AC fields in your database explorer, to then get that manual information drawn into your MyLog.  I get around 1200 aircraft a day logged and that gives me around 20 manual database amendments per day to keep every field updated in mylog. My box has been on 1hour toady and I already have two new blanks.  Both are Bizjets where the airliners.net picture information of 'untitled' has been removed by the Airnav server and replaced with a blank, as was vocally requested by forum users.  I am now going to online registers to find th correct owner information to place in the AC field of database explorer.

Regards
ACW

[DaveReid]

AN is just interested to get something for free (for instance our data) and sell it then for a "reasonable" price....

Come on, don't be so hard on AirNav. 

If you're able to sell information back to the users who provided it, at a profit, and without having to accept any responsibility for its accuracy, then it's no surprise that you don't place any value on a professional solution.

Personally, I'm past caring who AirNav use to fix the problem, I just wish they would fix it.  Speaking for a moment purely as a user, I'm fed up with my RadarBox telling me that I'm picking up aircraft that I know to be in a museum, or written off, or long since re-registered.

It's not rocket science, after all, and there are any number of vendors out there who specialise in collating the kind of information that RadarBox customers ought to be able to take for granted.

In fact I'd be equally delighted if AirNav went to, say, ICAO and asked to license their International Register of Civil Aircraft (IRCA) for use within the RadarBox database.  Then at least we would get the ICAO type designators correct, which would be a good start.

How's that for a constructive, unbiased suggestion ?