sensitivity radarbox-sbs1e

[RNAGG]

I made some tests in this weekend with the SBS-1 and perceived that I obtained to catch some aircraft that were in the SBGR ground. Also I obtained to follow the landings and takes-off and the taxi in the ground. However, when I placed the RB alone I obtain to catch the aircraft settling and soon later it disappears of the radar.
What it can be happening so that the RB does not obtain to catch these aircraft?

Obs.: I did not make no change in the external antenna.

[Allocator]

The only way to test this properly is to have both boxes running at the same time, side by side.  You seem to be using an external antenna, so did you have to use an adapter to connect the antenna to the RadarBox, but not to the SBS-1?

Have you got the airfield QNH set in RadarBox?  There is no option to do this with the SBS-1, so the altitude displayed on RB will be correct, but the SBS-1 will always show the altitude relative to 1013.2 millibars - this can appear to make a difference.

In my tests, the SBS-1 and RadarBox produce broadly similar results - sometimes one box is better than the other at one height or distance, then the other is better in a different direction.

[RNAGG]

You seem to be using an external antenna, so did you have to use an adapter to connect the antenna to the RadarBox, but not to the SBS-1?

Yes, I´m used adapter in RB.

Have you got the airfield QNH set in RadarBox? 

Yes. I marked "Auto set QNH" in SmartView.

Thanks for your information!

[AirNav Development]

We believe this was already explained in a previous post. ADS-B signals are transmitted in a frequency that is very sensitive to small changes/interferences. If you move your antenna a few centimeters you could receive more or less 50% of the traffic. Also you have to use an antenna that exactly matches the receiver you are using.

DaveReid: it is very strange that you constantly point out that we shouldn't make direct statements against our competition and then send such a post.

Anyway the answer is simple: have a look at the post below on the Kinetic Avionics forum:
http://www.kinetic-avionics.co.uk/forums/viewtopic.php?t=9219&highlight=

Copied from that post:
"3 units into one antenna through an RF Systems RF Splitter to present equal match to all boxes showed that the SBS-1e consistently over a 24 hour period gave 2 or 3 aircraft more than the other 2 units. Due to the way ADSP is handled it is meaningless to publish figures about db etc. "

On this post they mention that they didn't do any lab tests to compare the units. They were simply put side by side with the "same" conditions (with an antenna that matches SBS and not RadarBox). This is, as you may understand, a non professional way to compare the units and to promote a product using something that it does not have (increased sensitivity).

This is, of course and illegal and invalid claim that is, unfortunately, typical from our competition, a company that claimed it had, for example a network feature (mapmode-s) for 3 years without having it and sold units based on false advertisements.

[DaveReid]

DaveReid: it is very strange that you constantly point out that we shouldn't make direct statements against our competition and then send such a post. Are you hiding something?

On the contrary, I have absolutely no problem with either AirNav or Kinetic claiming to be better then the competition in specific areas provided that they are each able to back up their statements.

I was simply pointing out that I would like to see AirNav's comparison document updated to show RadarBox vs SBS-1e.  I would be equally critical of Kinetic if they published a comparison based on an older version of RadarBox.

I think that's fair.  Don't you ?

[AirNav Development]

It is fair and we will update that document within the next days.
Anyway what is your opinion regarding ML&S false advertisement on more sensitivity? I would like to know your opinion on this one.

Do you believe it is fair to state that assuming that no lab tests were made?

[Allocator]

You seem to be using an external antenna, so did you have to use an adapter to connect the antenna to the RadarBox, but not to the SBS-1?

Yes, I´m used adapter in RB.

Have you got the airfield QNH set in RadarBox? 

Yes. I marked "Auto set QNH" in SmartView.

Thanks for your information!

The adapter will reduce the signal strength a little.

[porter]

If w're talking about claims in advertising, then just take a look at Transair's spring catalog (copy attached).  They claim that with the SBS-1 you can "Globally Monitor The Skies", and "share your information with other users via a broadband data stream network for global tracking of aircraft traffic".  Features that I associate with the Radarbox rather than the SBS-1.

Confusing isn't it?

[Terry]

Gentlemen please,
                           You both have very valid points which are duly noted and read Not only by RB and SBS users,but by many prospective customers for both systems who MAY think that looking at the little sniping remarks that they may not bother with ANY of the systems until a level of order has been reached on this matter,i mean NO offence to any of you,but surely an e-mail or phone call to each other would be better,then you could reach some amicable arrangement and not publicly digress into bickering,i`m sure this would be better for us all and the "HOBBY".just my view at this time reading the RB and Kinetic forums.


                       Regards Terry.
 

[DaveReid]

Anyway what is your opinion regarding ML&S false advertisement on more sensitivity? I would like to know your opinion on this one.

The current ML&S ad comparing SBS-1e to SBS-1 includes the two statements "Better than 3db increase in sensitivity than original SBS-1" and "Up to 20% more aircraft viewable on screen (under multiple test conditions)".

I have no idea what the first statement means;  the second seems pretty straightforward and should be easy enough to prove or disprove.  Not having an SBS-1e, I can't really comment from personal experience.

Do you believe it is fair to state that assuming that no lab tests were made?

Well I don't know enough about the radio side of Mode S receivers to be able to judge what does or doesn't constitute a valid lab test.  Speaking as a user, what would convince me would be a side-by-side, simultaneous demo where one could readily see whether or not Box A was pulling in more aircraft than Box B.

[Terry]

Dave.
         I would be glad to do a test between the SBS1 and the RB if you want.I can use the same antenna which is on the side of the house so no movement there,just plug in each box and see what the difference is,if this will suffice.


            Regards Terry.
                         

[DaveReid]

I would be glad to do a test between the SBS1 and the RB if you want.I can use the same antenna which is on the side of the house so no movement there,just plug in each box and see what the difference is,if this will suffice.

Thanks for the offer, Terry.  The problem with that approach is that you're not looking at the same aircraft in the same locations with each box.  If you unplug Box A and plug in Box B, and aircraft X is no longer visible, is it because Box B is less sensitive or because the aircraft is now further away from you? (or possibly just further from the Mode S interrogator?)

Better would be two boxes running side-by-side, fed by two separate antennae, with the aerials swapped over halfway through the test session to eliminate differences resulting from them.

[AirNav Development]

DaveReid: ok on your messages but do you think it is valid to make those statements without a valid scientific/lab test?

[Terry]

I quite understand your point Dave and see where your coming from.

                 Regards Terry.

[viking9]

DaveReid: ok on your messages but do you think it is valid to make those statements without a valid scientific/lab test?

Hang on chaps. Of course Dave's test is valid. What is the purpose of the RB? It's to detect aircraft. The only valid test is a side by side test at the same location. I've done it a few times, (latest was last Thursday at RAF Mildenhall) and found absolutely no difference in numbers of ac between my RB and two SBS-1s.