KEETARP
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I don't really understand why you brought EO-DAS into this .
But what I can make out is you meant
1) SPECTRA is =equal to or better than EO-DAS
2) Euro-DAS dosen't gives all-round coverage .
3) F18G which is a dedicated EW platform is inferior to Rafale in Electronic attack capabilities
4) F18 having HARM for DEAD (in addition to excellent stand-of weapons) is at disadvantage to Rafale which dosen't have any HARM capability .
Let me explain my POV
1) EO-DAS is a generation ahead of SPECTRA , why ??
Would be better if Gambit/DBC enlighten us ,
but let me try for time-being by a quote by director L.Martin
The red - part explains very well why EO-DAS is unmatched .
6ix optical IR ( Thermal imaging) cameras are distributed and integrated on aircraft's surface to provide a video/digital image into displays of not only threat but also whole battle-field picture .
Compare it to Rafale - Only one camera that is TV imaging and that too a part of front-sector-optronics unit covering only a sector of hemisphere .
Tests begin on Rafale optronics-05/05/1999-Flight International
read the first para of article about separate irst and separate tv imager
See the difference in above image display when a camera is attached on rt side .
Until Rafle gets six such FSO distributed on air-craft , it wont get that Imax effect . In addition the other passive sensors of rafale don't have imaging camera so only provide information about threat not surrounding .
Second about the technology of detection - Northrop.Grumman and L.Martin used infrared imaging instead of TV imaging for display . Additionly DAS used FPA(Focal plane array ) IR-detection and seeker coupled with Thermal-imager into a single unit to provide a better resolution/pixel/sensitivity into picture .
FPA is present on AIM-9x+Python5 , while Mica+R73+OSF lacks it .
I am not going into details why Thermal imaging is better than TV imaging ( highly sensitive Thermal imager's are only allowed for military purposes speaks for itself )
but in short TV imager requires in addition to detectors - a Multiplexer + a transmission line + a FPS controller to render images at exactly at 25FPS to avoid flickering + A synchronizer to deactivate pixel-by pixel photons and brightness to match display,
Further everytime a Pixelated picture is generated - TV scans the pixels line by line (ignoring interlace), starting at the top, say left hand corner, scanning to the end of the line, then jumping back to the beginning of the second line and repeating the process until the whole image has been scanned, top to bottom.
All of this must of course happen within the short period of time allocated to that particular frame. The process is thus repeated, say 25 times a second. Here is where one of the troublesome aspects of TV becomes apparent. Consider an array of say 488 x 380 pixels. To transmit a continuous TV picture we must then transmit around 185,000 brightness samples 25 times a second and that is a lot of information (around 2000 voice channels). The problem is unfortunate as the finer the resolution (or higher the pixel density) or quality of the picture, the greater the channel capacity required, which translates into faster and thus more expensive electronics.
In comparison the FPA -
FPAs are however much easier to support than vidicon based TV and mechanically scanned FLIR, as most of the timing, control and level amplifying electronics are very compact (and often on the same substrate) and consume little power. The only outside support required is refrigeration (i.e. placing the whole FPA into a Dewar module, or glueing it on to a thermoelectric Peltier solid state refrigerator) and of course mechanical stabilisation.
initially filters out visible and undesired infrared light with a special window (usually an interference filter, hence the mirror look). The 'cleaned up' (spectrally) IR then enters the optics, which provide specific viewing angles (usually NFOV and WFOV) for specific systems, the optics are usually changed mechanically.
Signal processing chips (here virtually only the die) and connections are then also attached, creating a hybrid module instead of separate link channels .
There are two broad families of FPAs, discrete and monolithic
Monolithic FPAs come in two basic families, the simpler CID (Charge Injection Device) and the more sophisticated CCD (Charge Coupled Device) , The CCD imaging array contains all the necessary support circuits and as such is a complete TV camera, needing only a lens and wires to connect up the power and a timing reference (sync).
But what I can make out is you meant
1) SPECTRA is =equal to or better than EO-DAS
2) Euro-DAS dosen't gives all-round coverage .
3) F18G which is a dedicated EW platform is inferior to Rafale in Electronic attack capabilities
4) F18 having HARM for DEAD (in addition to excellent stand-of weapons) is at disadvantage to Rafale which dosen't have any HARM capability .
Let me explain my POV
1) EO-DAS is a generation ahead of SPECTRA , why ??
Would be better if Gambit/DBC enlighten us ,
but let me try for time-being by a quote by director L.Martin
"Designated the AN/AAQ-37, and comprising six electro-optical sensors, the full EO DAS like EOTS , the F-35's distributed aperture system is incorporated in the fuselage design and does not require a pod. Six IR cameras--Porter calls them situation awareness "eyeballs" that create a flying "Imax"--are embedded in the aircraft, positioned to provide full spherical imagery around the aircraft.
The red - part explains very well why EO-DAS is unmatched .
6ix optical IR ( Thermal imaging) cameras are distributed and integrated on aircraft's surface to provide a video/digital image into displays of not only threat but also whole battle-field picture .
Compare it to Rafale - Only one camera that is TV imaging and that too a part of front-sector-optronics unit covering only a sector of hemisphere .
Tests begin on Rafale optronics-05/05/1999-Flight International
read the first para of article about separate irst and separate tv imager
See the difference in above image display when a camera is attached on rt side .
Until Rafle gets six such FSO distributed on air-craft , it wont get that Imax effect . In addition the other passive sensors of rafale don't have imaging camera so only provide information about threat not surrounding .
Second about the technology of detection - Northrop.Grumman and L.Martin used infrared imaging instead of TV imaging for display . Additionly DAS used FPA(Focal plane array ) IR-detection and seeker coupled with Thermal-imager into a single unit to provide a better resolution/pixel/sensitivity into picture .
FPA is present on AIM-9x+Python5 , while Mica+R73+OSF lacks it .
I am not going into details why Thermal imaging is better than TV imaging ( highly sensitive Thermal imager's are only allowed for military purposes speaks for itself )
but in short TV imager requires in addition to detectors - a Multiplexer + a transmission line + a FPS controller to render images at exactly at 25FPS to avoid flickering + A synchronizer to deactivate pixel-by pixel photons and brightness to match display,
Further everytime a Pixelated picture is generated - TV scans the pixels line by line (ignoring interlace), starting at the top, say left hand corner, scanning to the end of the line, then jumping back to the beginning of the second line and repeating the process until the whole image has been scanned, top to bottom.
All of this must of course happen within the short period of time allocated to that particular frame. The process is thus repeated, say 25 times a second. Here is where one of the troublesome aspects of TV becomes apparent. Consider an array of say 488 x 380 pixels. To transmit a continuous TV picture we must then transmit around 185,000 brightness samples 25 times a second and that is a lot of information (around 2000 voice channels). The problem is unfortunate as the finer the resolution (or higher the pixel density) or quality of the picture, the greater the channel capacity required, which translates into faster and thus more expensive electronics.
In comparison the FPA -
FPAs are however much easier to support than vidicon based TV and mechanically scanned FLIR, as most of the timing, control and level amplifying electronics are very compact (and often on the same substrate) and consume little power. The only outside support required is refrigeration (i.e. placing the whole FPA into a Dewar module, or glueing it on to a thermoelectric Peltier solid state refrigerator) and of course mechanical stabilisation.
initially filters out visible and undesired infrared light with a special window (usually an interference filter, hence the mirror look). The 'cleaned up' (spectrally) IR then enters the optics, which provide specific viewing angles (usually NFOV and WFOV) for specific systems, the optics are usually changed mechanically.
Signal processing chips (here virtually only the die) and connections are then also attached, creating a hybrid module instead of separate link channels .
There are two broad families of FPAs, discrete and monolithic
Monolithic FPAs come in two basic families, the simpler CID (Charge Injection Device) and the more sophisticated CCD (Charge Coupled Device) , The CCD imaging array contains all the necessary support circuits and as such is a complete TV camera, needing only a lens and wires to connect up the power and a timing reference (sync).
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