Surely enough the lineage of Key Holes was long split between high-resolution (Gambit, Dorian) and broad mapping (Corona and Hexagon). I always felt that the KH-11 more belonged to the high-resolution camp and thus that the KH-9 capability was never fully replaced. Looks like they regretted it in GW1. Which begs an interesting question: was there a KH-9 successor project somewhere between 1971 and 1985 ? Both Corona and Hexagon produced enormous volumes of photos. One can wonder if KH-11 -era digital memory storage could have handled such volume. I wonder what is harder from a storage point of view: small number of very high resolution pictures OR a boatload of medium resolution pictures ?
Dare I suggest Lacrosse? It first launched in 1988. With the Challenger accident delays, it could very well have been the intended 1985 system.
Quote from: kevin-rf on 04/27/2017 06:30 pmDare I suggest Lacrosse? It first launched in 1988. With the Challenger accident delays, it could very well have been the intended 1985 system.No.
Quote from: Blackstar on 04/27/2017 07:37 pmQuote from: kevin-rf on 04/27/2017 06:30 pmDare I suggest Lacrosse? It first launched in 1988. With the Challenger accident delays, it could very well have been the intended 1985 system.No.So what was it? Was the search capability picked up by the KH-11, by other means like some form of SIGINT, or just not needed?
The one thing it certainly wasn't and that was Lacrosse.
Quote from: Star One on 04/28/2017 07:43 amThe one thing it certainly wasn't and that was Lacrosse.Sorry to derail the thread, but seems some people are very adamant that LACROSSE could not fill the KH-9 role.I am a little curious as to why. Too narrow a field of view? Active scanning is not stealthy enough? Doesn't show everything that optical imaging can?Not enough power/bandwidth to cover everything needed?Not high enough resolution?Just curious.
Quote from: kevin-rf on 04/28/2017 02:57 pmQuote from: Star One on 04/28/2017 07:43 amThe one thing it certainly wasn't and that was Lacrosse.Sorry to derail the thread, but seems some people are very adamant that LACROSSE could not fill the KH-9 role.I am a little curious as to why. Too narrow a field of view? Active scanning is not stealthy enough? Doesn't show everything that optical imaging can?Not enough power/bandwidth to cover everything needed?Not high enough resolution?Just curious. Yes.
According to a newly-declassified document I have, they "solved" the wide-area search requirement by increasing the bandwidth for the KH-11 system (that includes the SDS relay satellites). Now if that really satisfied the requirement, or they changed the requirement and it was different than before, I don't know. But that's what I got.All this reminds me that I should write part 2 of my "Black Ops and the Shuttle" series and address WASP and ZEUS in greater detail.
Is the bandwidth requirements why they need to have some Quasar satellites in Molynia orbits so that there is total global coverage.
According to a newly-declassified document I have, they "solved" the wide-area search requirement by increasing the bandwidth for the KH-11 system (that includes the SDS relay satellites).
Now if that really satisfied the requirement, or they changed the requirement and it was different than before, I don't know. But that's what I got.
All this reminds me that I should write part 2 of my "Black Ops and the Shuttle" series and address WASP and ZEUS in greater detail.
The satellite’s average radar resolution was reported to be about one meter, probably in the standard “pushbroom” mode where the radar essentially looks straight down and takes a continuous image, like a push broom being pushed across a floor. However, synthetic aperture radars have a mode called “spotlighting” whereby they spend several seconds taking repeated images of the same small area to improve resolution. By taking images for up to 17 seconds, Onyx reportedly could obtain a resolution of about 0.3 meters for a small area.
Don't forget, the missile launcher is much larger than say a car or random rock, and should have a much stronger radar return. The point being, the radar "image" doesn't have to be the highest resolution if the launcher has some unique radar characteristics. It doesn't even need to resolve the a launcher, especially if they have previously mapped the general area, and it's radar return just sticks out like a sore thumb.That said, the German TIRA made and released some very high resolution images of the failed Phobos-Grunt Mars probe a few years back. It proves it is within the realm to be able to produce high resolution radar images.
I found one article by Dwayne Day with resolution figures for Lacrosse:http://www.thespacereview.com/article/790/1Radar love: the tortured history of American space radar programsQuoteThe satellite’s average radar resolution was reported to be about one meter, probably in the standard “pushbroom” mode where the radar essentially looks straight down and takes a continuous image, like a push broom being pushed across a floor. However, synthetic aperture radars have a mode called “spotlighting” whereby they spend several seconds taking repeated images of the same small area to improve resolution. By taking images for up to 17 seconds, Onyx reportedly could obtain a resolution of about 0.3 meters for a small area.It support my explanation above: with 1m resolution in radar in wide-swath mode, Lacrosse is worse than Hexagon for wide-area intelligence search. The article dates back to 2007 though, so maybe new information has come to light.Quote from: kevin-rf on 04/30/2017 02:15 amDon't forget, the missile launcher is much larger than say a car or random rock, and should have a much stronger radar return. The point being, the radar "image" doesn't have to be the highest resolution if the launcher has some unique radar characteristics. It doesn't even need to resolve the a launcher, especially if they have previously mapped the general area, and it's radar return just sticks out like a sore thumb.That said, the German TIRA made and released some very high resolution images of the failed Phobos-Grunt Mars probe a few years back. It proves it is within the realm to be able to produce high resolution radar images. Yes, though as explained above, a radar sat usually has a low-resolution mode with a wide swath and a high-resolution mode with a small swath.
It appears that Lacrosse 5 has a planar radar antenna, unlike the dish antennas of earlier Lacrosses, notes satellite watcher, Allen Thomson, who recently posted the Russian paper.
You should keep in mind that it's known the antenna designs of the Onyx satellites altered across the programs life as they appear to have been constructed in two blocks, I suspect this reflected changes in their capabilities. Also in these two blocks Onyx 5 had a completely different antenna design to those before it. This was established when images of them in orbit were put online.
Quote from: Star One on 04/30/2017 07:37 pmYou should keep in mind that it's known the antenna designs of the Onyx satellites altered across the programs life as they appear to have been constructed in two blocks, I suspect this reflected changes in their capabilities. Also in these two blocks Onyx 5 had a completely different antenna design to those before it. This was established when images of them in orbit were put online.And don't forget, a third design (fourth if USA-193 is included) for the current generation (TOPAZ). The current generation is now built by Boeing. They whole class has evolved significantly since 1988.