Accuracy of the APG-81.

Unread postPosted: 07 Sep 2018, 00:38
by ricardonb2
Is the angular accuracy of the APG-81 only 1 degree ? Is this the angular accuracy of the APG-81 or ESM ?

https://vanguardcanada.com/2014/05/21/j ... iven-data/

Re: Accuracy of the APG-81.

Unread postPosted: 07 Sep 2018, 08:54
by Dragon029
Equally important, where fourth generation radar are able to detect the arrival of a threat with plus or minus 30 degrees accuracy, the F-35 can pinpoint the threat to within plus or minus one degree, an advantage that is narrowed further with the assistance of a formation of four aircraft sharing that threat trajectory, he says.


That would be ESM and would also an approximation; 4th gen fighter radars are capable of determining a threat's bearing with far more accuracy than 30 degrees.

Re: Accuracy of the APG-81.

Unread postPosted: 07 Sep 2018, 08:59
by hornetfinn
I'd say that accuracy statement refers to ESM angular accuracy. Many 4th gen RWRs have about that 30 degree accuracy, although some later systems have better than that (like 5-10 degrees typically). One degree accuracy is really great and requires interferometer antennas which have traditionally been used in dedicated ELINT/ESM platforms. It's possible to put such system on 4th gen fighter and I think Praetorian DASS in EF Typhoon, ALQ-214 in SH and Thales Spectra in Rafale might be close to F-35 numbers also. Naturally VLO stealth will allow F-35 to get closer to target and get even more precise information. MADL will allow number of F-35s to share that data in a manner that is impossible with Link 16 only.

Re: Accuracy of the APG-81.

Unread postPosted: 07 Sep 2018, 10:50
by aasm
hornetfinn wrote:I'd say that accuracy statement refers to ESM angular accuracy. Many 4th gen RWRs have about that 30 degree accuracy, although some later systems have better than that (like 5-10 degrees typically). One degree accuracy is really great and requires interferometer antennas which have traditionally been used in dedicated ELINT/ESM platforms. It's possible to put such system on 4th gen fighter and I think Praetorian DASS in EF Typhoon, ALQ-214 in SH and Thales Spectra in Rafale might be close to F-35 numbers also. Naturally VLO stealth will allow F-35 to get closer to target and get even more precise information. MADL will allow number of F-35s to share that data in a manner that is impossible with Link 16 only.


It is well documented that Spectra RWR, using interferometry have an angular accuracy "under 1°". Btw, there are also MBDA stuff in Spectra.

Re: Accuracy of the APG-81.

Unread postPosted: 08 Sep 2018, 04:41
by michaelemouse
A search radar with 30-degree accuracy would be underwhelming whereas it's good enough to know which way an enemy missile is coming.

Is there some formula which allows one to calculate the approximate angular accuracy of a radar? I know that monopulse tracking and other forms of radar integration methods can increase accuracy further but if one wants to know what a simple monobeam transmission can do, what would that look like?