SPO-10 RWR

[AeriaGloria]

   What do you all think of SPO-10 in our Mi-24P? It seems very different from SPO-10 in MiG-21bis. I’m sure there can be different versions, as SPO-15 is upgraded in Su-27 versus MiG-29/ash-25. But the differences seem quite major 

   It seems to me that beeps/lights seem to last much longer in Mi-24P, and don’t change according to distance very much if at all. It is very hard to tell when you are locked, as tone only increases in frequency to maybe 2 hz, very little from the approximately .5-1x every second. When locked in MiG-21bis the lights/beep is nearly constant, which makes sense as the analogue antenna is merely telling you when radar emmision passed over, which in STT would be nearly constant.  
 

   And upon proximity it doesn’t seem to light up all four lights as it does in MiG-21bis, I always thought the reason being that at close range the strength of the signal overwhelms and floods the directional antennas on all sides with signal. In addition the MiG-21bis seems to increase frequency of beeps/lights the closer the emission is, and there seems to be some real life acknowledgement of this. I would assume the closer you are the more you are in the main beam, and the stronger the side loves are and closer to being. Detected. 
 

   These differences make it harder to distinguish where threats are. When you are being locked. And comparative proximity. I would be very interested if there are technical differences between the two SPO-10 versions, or wether ED is working off separate info that either doesn’t have the information or has different information. I know Magnitude 3 overhauled their SPO-10 a few years ago after receiving Polish documents with much more detail. If they are indeed the same system in both, it would be very nice if Magnitude 3 either has the authority to give ED access to these documents or allow them to use their SPO-10 simulation or Atleast the same concepts. 
 

   I would appreciate anyones thoightd or experiences, especially if you’ve done testing or air to air combat or been up against many different kinds of radars 

Edited April 25, 2022 by AeriaGloria

[Dragon1-1]

Neither is correct. SPO-10 should work like the Viggen's RWR, with different sounds according to what radar is painting you. That's the biggest thing missing, currently in the MiG-21 you can't tell whether the beep is from a friendly search radar or an enemy fighter out for your blood. It should be quite audible, the same way it is in the Viggen (indeed, it should sound exactly the same). There are no differences in how it works between the real Mi-24 and MiG-21.

[AeriaGloria]

3 hours ago, Dragon1-1 said:

Neither is correct. SPO-10 should work like the Viggen's RWR, with different sounds according to what radar is painting you. That's the biggest thing missing, currently in the MiG-21 you can't tell whether the beep is from a friendly search radar or an enemy fighter out for your blood. It should be quite audible, the same way it is in the Viggen (indeed, it should sound exactly the same). There are no differences in how it works between the real Mi-24 and MiG-21.

As in turning the PRF into audio? I’ve never heard of SPO-10 having this ability 

[Dragon1-1]

This is not really an "ability", all early RWRs worked like this by default (except the one in MiG-19, but that one was meant to warn against a radar-guided guns shot, not SAMs). AFAIK, SPO-10 included, although I don't have any original docs stating that. The most basic RWR is basically an AM radio tuned into radar frequencies. It has a bunch of directional antennas, which light a corresponding light when they have a signal. That's all there is to it, only later did the RWR gear get more elaborate, such as the SPO-15, which could classify emissions to some extent (and I'm not sure if they ditched the direct audio output with it or not).

[AeriaGloria]

1 hour ago, Dragon1-1 said:

This is not really an "ability", all early RWRs worked like this by default (except the one in MiG-19, but that one was meant to warn against a radar-guided guns shot, not SAMs). AFAIK, SPO-10 included, although I don't have any original docs stating that. The most basic RWR is basically an AM radio tuned into radar frequencies. It has a bunch of directional antennas, which light a corresponding light when they have a signal. That's all there is to it, only later did the RWR gear get more elaborate, such as the SPO-15, which could classify emissions to some extent (and I'm not sure if they ditched the direct audio output with it or not).

Yeah I mean if there is any information purporting what you say, I’m all ears. 
 

Pretty sure the distance to beep frequency in MiG-21 is fixed, 1 beep at 40-89 km and 3 beeps at less then 40, with a 80 km max range. Interesting that a Mi-24 book claims 45-50 km, but I’m sure that’s from increased radar horizon from low altitude. 

[Dragon1-1]

An RWR doesn't have a way to measure distance, so the "distance to beep frequency" thing can't be true generally. It does not really have a maximum range, either. It might be true for a specific radar operating in a specific mode, or a generalized rule of thumb for a class of radars, but what RWR measures is radar signal strength. A SA-10 radar locking you from 100km slant range may have a higher signal strength than a ZSU-23 in search mode at 10km (not sure if that's actually the case, but you catch my drift). In an environment with multiple EM radiation sources, even if it was something like "signal strength to beep frequency", it'd tell you much less than hearing the signal itself would. The current implementation of SPO-10 in the MiG-21 is, in a real environment, useless for anything short of a lock, and then, it doesn't tell you where the lock comes from. 

Maybe it really was that bad, but I'd need to find real manuals to check for sure. 

[AeriaGloria]

3 hours ago, Dragon1-1 said:

An RWR doesn't have a way to measure distance, so the "distance to beep frequency" thing can't be true generally. It does not really have a maximum range, either. It might be true for a specific radar operating in a specific mode, or a generalized rule of thumb for a class of radars, but what RWR measures is radar signal strength. A SA-10 radar locking you from 100km slant range may have a higher signal strength than a ZSU-23 in search mode at 10km (not sure if that's actually the case, but you catch my drift). In an environment with multiple EM radiation sources, even if it was something like "signal strength to beep frequency", it'd tell you much less than hearing the signal itself would. The current implementation of SPO-10 in the MiG-21 is, in a real environment, useless for anything short of a lock, and then, it doesn't tell you where the lock comes from. 

Maybe it really was that bad, but I'd need to find real manuals to check for sure. 

I’m aware, I’m just saying that’s the current DCS implementation. 80 km max, and 40 km for triple beeps for MiG-21. While there are sources saying 50 km for Mi-24 SPO-10, I’m sure that has more to do with radar horizon and comparison of some sort of average Soviet/Warsaw pact radar, as you said rule of thumb or with a specific radar/radar mode in mind like. Typical encounter SAM

Only real world sources available for SPO-10 probably say that for some reason or assumption or based off of one comparison. As there is very little publically available information on the net. We don’t have much to go by.

Everything I had read, the SPO-10 was basically the MIG-19 tail warning radar on four directions, with more advanced small electronics. 
 

I don’t expect something amazing, I’m just interested by how much more useful the MiG-21 implementation is, and wonder what can be figured out about the real system and if there is a basis for ED’s implementation, or any way to perhaps see room for improvement. I mean you say the MiG-21 is good for showing you a lock, and as long as it’s far enough away it will tell you bearing off the lock within 45 degrees. But the Mi-24 can barely tell you there’s a lock at all lol 

Edited April 26, 2022 by AeriaGloria

[Dragon1-1]

I actually found a full technical manual for the SPO-10, complete with circuit drawings. There's only one problem with it, really. It's all in Russian.  Still, the answer must be in there somewhere.

It's from 1976 and presumably unclassified (not that I can understand much of what it says, except said circuit drawings), so I'm uploading it. 

SPO-10(1976).djvu

[AeriaGloria]

1 hour ago, Dragon1-1 said:

I actually found a full technical manual for the SPO-10, complete with circuit drawings. There's only one problem with it, really. It's all in Russian.  Still, the answer must be in there somewhere.

It's from 1976 and presumably unclassified (not that I can understand much of what it says, except said circuit drawings), so I'm uploading it. 

SPO-10(1976).djvu 2.95 MB · 2 downloads

Wow, this might be useful!!!!

[AeriaGloria]

2 hours ago, Dragon1-1 said:

I actually found a full technical manual for the SPO-10, complete with circuit drawings. There's only one problem with it, really. It's all in Russian.  Still, the answer must be in there somewhere.

It's from 1976 and presumably unclassified (not that I can understand much of what it says, except said circuit drawings), so I'm uploading it. 

SPO-10(1976).djvu 2.95 MB · 2 downloads

Have been able to translate it page by page. Trying to find pages that list operation rather then technical specifics. It is certianly a technical manual with the information needed for maintenance and troubleshooting, and description of all components. I did find so far only this for description of use in flight. I have not been able to notice the “beeps increase in frequency with proximity” in DCS Mi-24P. Perhaps I just haven’t noticed it? I do know. That when locked it certianly is never even close to 6 Hz signal tone 

 

 

Page 62 and 65,

“in flight.  When the aircraft is irradiated from any direction, the corresponding light on the indicator lights up and in time with the

 By moving the light bulb, an audible signal is given to the SPU and UKR.

 If irradiation occurs in the survey mode (bursts of pulses), then the alarm will be triggered at the scanning frequency of the irradiating radar antenna, and when the irradiating radar approaches, the frequency of the alarm will increase, and decrease when moving away.  This occurs because, as the aircraft approaches, the time of irradiation of the aircraft increases, while the time between irradiations decreases at the same scan periods, which gives the impression of an increase in frequency.  At removal, the opposite happens.  If the irradiating radar enters the tracking (aiming) mode, then the light signaling will be continuouS flicker and in time with flicker (with a frequency of about 6 Hz) synchronous  with light will be given an audible alarm in the SPU (intercom) and UKR. 

 If there is exposure in the view mode by several aircraft radars from different directions, then several lights of the corresponding sectors light up.  With such irradiation, the bulbs light up out of sync.

 When irradiated straight-front, straight-right, straight-left and straight-behind, signals are received by two antennas of adjacent sectors.  In this case, two corresponding bulbs will light up in time with each other.

 If the irradiating radar is approaching at a 1/4 and 3/4 angle, then two bulbs of neighboring sectors may light up.  In this case, the radiation sector should be judged by the bulb that lights up first.  In the future, both bulbs will light up synchronously.”

I will attach two photos of translated table of contents.

I might test again and see if there really is no “6 HZ locked mode,” or “change of signal frequency with distance,” it might be worth it to make a bug report based off of this?

And based off this, the user manual portion not mentioning that all lights light up when tracking radar is close, must be out of personal experience of pilots when radar signal overwhelms directional antennas of all four stations? Even without that, having the beep frequency relate to distance and at most 6 HZ for lock would go towards making the system work more as it does in reality perhaps 

 

Edited April 26, 2022 by AeriaGloria

[AeriaGloria]

Going to post two bug reports. 
 

I did find something though, all 4 RWR lights will light up if you are close enough to emitter in search or track mode. It’s just VERY close. Merge close. But still cool to see 

[Dragon1-1]

3 hours ago, AeriaGloria said:

I have not been able to notice the “beeps increase in frequency with proximity” in DCS Mi-24P. Perhaps I just haven’t noticed it? I do know. That when locked it certianly is never even close to 6 Hz signal tone 

It appears that what it means is that the RWR beeps whenever it receives a signal. That said, this is a strange statement. In scanning mode, this means it'll beep each time the antenna sweeps over you. Since the period of the scan is the same, so the time between each time it sweeps over you is the same. What will happen is that you will be in the sector being scanned for longer at close range, so the beep will last longer, and the the interval will decrease. Not sure how noticeable that'd be, though.

Also, it still doesn't tell us whether the "beep" is audio from the RWR or a simple beeper (unless the original text is less ambiguous). 

Edited April 26, 2022 by Dragon1-1

[AeriaGloria]

4 minutes ago, Dragon1-1 said:

It appears that what it means is that the RWR beeps whenever it receives a signal. That said, this is a strange statement. In scanning mode, this means it'll beep each time the antenna sweeps over you. Since the period of the scan is the same, so the time between each time it sweeps over you is the same. You will be in the sector being scanned for longer at close range, so the beep will last longer, and the the interval will decrease.

Also, it still doesn't tell us whether the "beep" is audio from the RWR or a simple beeper. 

Are you saying the frequency of beeps increasing with proximity given the same scan rate does not make sense? 

[Dragon1-1]

Yes, but I read it again, and beeps do not increase in frequency. It's just as I said, they increase in duration, and this causes the interval to drop, since the scan period is the same. The quiet periods does get shorter, giving you the impression that the beeps are more frequent, but they also become longer, and the frequency at which they start is the same.

[AeriaGloria]

20 minutes ago, Dragon1-1 said:

Yes, but I read it again, and beeps do not increase in frequency. It's just as I said, they increase in duration, and this causes the interval to drop, since the scan period is the same. The quiet periods does get shorter, giving you the impression that the beeps are more frequent, but they also become longer, and the frequency at which they start is the same.

Ahhh I see

[Frederf]

My understanding is that there are three levels of reporting on a sector channel. During the reception cycle the incomming signal charges a memory device like a capacitor. The discharge of the built up charge comes as a series of flashes and beeps.

Low signal is a single flash like flash-off-off. Medium signal is flash-flash-off. High signal is flash-flash-flash.

The time slots for the three events are just about long enough that if three flashes are shown then the next three flashes from the next cycle are a continuation of the same pattern.

The cycles are of fixed interval but their contents vary.

Again my impression is that flashes/beeps are a way of indicating different magnitudes of total signal collected over the reception window, not raw information about when or how you were swept. The average frequency of flashes would change as second or third flashes would not happen for low or medium signal sums.

[Dragon1-1]

Is this based on the manual I posted? The translated bit quite unambiguously indicated that it's not about signal strength, but time of illumination by the radar. It doesn't have a "reception cycle". FYI, this is a technical manual, which basically means an SPO-10 bible. This is what a Soviet crew chief would use when fixing one of these.

[AeriaGloria]

1 hour ago, Dragon1-1 said:

Is this based on the manual I posted? The translated bit quite unambiguously indicated that it's not about signal strength, but time of illumination by the radar. It doesn't have a "reception cycle". FYI, this is a technical manual, which basically means an SPO-10 bible. This is what a Soviet crew chief would use when fixing one of these.

There does seem to be indication of a specific reception window measured in nano seconds. And that the tone is 800 HZ. I will see if I can translate more

Trying to find mention people have said that all four lights light up at 2-5 km for most radars, and 20-25 km for the Soviet ground beacons/radars. 

[ebabil]

The RWR in our version is doing nothing other than banging our ears. I hope at least we had spo-15

 

 

[Dragon1-1]

Well, since it turns out it doesn't turn the actual PRF to audio after all, that's more or less all it's good for IRL. The fundamental problem is, it's a fairly dumb device that beeps and flashes a light when it's got a signal on one of the antennas. It can tell you when someone's locking you in STT, but in an environment rich in radar emissions in its band, it'll just beep and flash uselessly, since you have nothing to tell you what's making it beep.

Maybe excluding some radars based on their frequency would help (for example, SPO-10 supposedly couldn't detect the Tomcat's AWG-9 in Iran-Iraq war), but even then, a bunch of friendly MiGs in the wrong place will set it off. SPO-15 was a big step up, since it had some electronics that could classify and prioritize emissions to some extent (according to one webpage, Western radars had priority, and Nike Hercules would always come first, makes sense given its purpose was to sling nukes at you).

Edited April 26, 2022 by Dragon1-1

[Frederf]

 

1 hour ago, Dragon1-1 said:

Is this based on the manual I posted? The translated bit quite unambiguously indicated that it's not about signal strength, but time of illumination by the radar. It doesn't have a "reception cycle". FYI, this is a technical manual, which basically means an SPO-10 bible. This is what a Soviet crew chief would use when fixing one of these.

I believe you. By strength I mean that loosely as "amount". If the system just integrates over time above a threshold signal that would have similar behavior.

[okopanja]

On 4/26/2022 at 10:55 PM, Dragon1-1 said:

(according to one webpage, Western radars had priority, and Nike Hercules would always come first, makes sense given its purpose was to sling nukes at you).

That info is from real manual for 29, and not only that: the manual from 87 updated in 89 states there is a second light on signal strength scale flashing at 2Hz. This one indicates earliest time the bandit can launch his primary weapon at you. Clearly this is missing in DCS. About SPO-10, in dcs mig-21, one of the developers was actual mig-21 pilot. I would trust this implementation to be more accurate.

Regarding RWRs, they can tell you rough  distance if they are able to classify illumination and actual radar type.

Edited November 14, 2022 by okopanja

[AeriaGloria]

13 hours ago, okopanja said:

That info is from real manual for 29, and not only that: the manual from 87 updated in 89 states there is a second light on signal strength scale flashing at 2Hz. This one indicates earliest time the bandit can launch his primary weapon at you. Clearly this is missing in DCS. About SPO-10, in dcs mig-21, one of the developers was actual mig-21 pilot. I would trust this implementation to be more accurate.

Regarding RWRs, they can tell you rough  distance if they are able to classify illumination and actual radar type.

 

The MiG-21 SPO-10 has one weak point I think ED can correct though. In SPO-10 in MiG-21 DCS, when bandit passes about 35 km the beeps for every second goes from 1 to 3 beeps. In the manual, this increase in beeps (as you get closer and spend more time in radar cone) should reasonably be fluid. And while I don’t expect ED to tune it to the strength and scan rate of every radar. I would hope that some system of using am average scan power and scan rate could help give us even more realistic then MiG-21 DCS

 

 But yea, in DCS, if we had the MiG-21 SPO-10 instead in Mi-24, I think it would be much more effective. Lock tones are actual nearly solid lights/tone, so even if cluttered you can tell where lock comes from. And the increasing beeps past 35 km also helps filter out those that aren’t as big threats yet 

[bies]

The core of this problem is: ED and 3rd parties systems are not compatible/unified.

It should work like that: some 3rd party or ED developed some particular system - all other developers and ED are free to use it.

This would make everything more compatible and modules faster to develop. Plus less unexpected bugs after patch.

[Harlikwin]

1 hour ago, bies said:

The core of this problem is: ED and 3rd parties systems are not compatible/unified.

It should work like that: some 3rd party or ED developed some particular system - all other developers and ED are free to use it.

This would make everything more compatible and modules faster to develop. Plus less unexpected bugs after patch.

I'm not really sure about that. 

But at any rate, this is good info.