Showing posts with label radar. Show all posts
Showing posts with label radar. Show all posts

Monday, 22 January 2018

TOPAZ/FIA Radar 5, the NROL-47 payload

click image to enlarge
The small streak in the center of the image above in a bright blue, partially cloudy twilight sky, is TOPAZ/FIA Radar 5 (2018-005A, 43145), the NROL-47 payload (see a previous post) imaged in evening twilight of 19 January 2018 with the sun at only 8 degrees below the horizon and the satellite at 24 degrees elevation in the northwest.

NROL-47 was launched on 12 January 2018, a week before the photo above was taken. Shortly after launch, Cees Bassa and Scott Tilley already detected the payload by radio, determining a preliminary orbit from the Doppler curves with an orbital altitude near 1057 km and inclination near 106 degrees.

The first optical observations were done in the evening of January 14th, two days after launch, by Cees Bassa in the Netherlands, after which it was picked up by a number of other observers as well (amongst others Leo Barhorst in the Netherlands, Greg Roberts in South Africa and Paul Camilleri in Australia). The latest optical observations have improved the orbit for this new satellite and show it is in a 1048 x 1057 km, 106.0 degrees inclined orbit.

The payload was making very low (11-12 degrees maximum elevation) twilight passes in the north during the first few days after launch for my locality, where I have obstruction from buildings. Passes gradually climbed higher in the sky over the week, but also deeper into twilight. Combined with dynamic weather, I started to lose hope of imaging it, but finally was succesful in the evening of 19 January. I had a 24 degree maximum elevation pass in the southwest near 17h UT, with the sun barely 8 degrees below the horizon. The pass was high enough to clear rooftop level near culmination.

The weather was again very dynamic that evening, with fields of clouds forming as soon as the sun set. Using the 1.4/85 mm lens, I took a series of images while clouds were moving in fast. Due to the very bright sky background, I was restricted to 1 second exposures at 400 ISO.

After a first quick cursory check of the images on the camera's LCD screen I initially thought I had lost the battle against clouds and twilight. But upon a more thorough inspection on my laptop a day later, it turned out it was in the images after all, and with enough reference stars to get some decent astrometry from the images.

The payload is in a new orbital plane for TOPAZ/FIA Radar satellites. While all previous four TOPAZ/FIA Radar satellites are in a 123.0 degree inclined orbit, this new TOPAZ/FIA Radar 5 is in a 106.0 degree inclined orbit.

I had already inferred a new orbital plane for this satellite pre-launch (see a previous post), based on the launch azimuth, which deviated from that of previous TOPAZ/FIA Radar launches from Vandenberg. The new 106.0 degree orbital plane is within 2.5 degrees of my original pre-launch estimate. The orbital altitude is somewhat lower than I initially estimated.

click to enlarge

click to enlarge

Operating in two orbital planes was also the case of a previous series of radar satellites, the Lacrosse (ONYX) satellites, of which currently only Lacrosse 5 is still in orbit. These operated in two orbital planes, at 68 and 57 degrees orbital inclination.

The 123.0 degrees orbital inclination of TOPAZ/FIA Radar 1 to 4 is the retrograde equivalent of the 57 degree inclination of the Lacrosse constellation. The new 106 degree orbital inclination is however not the equivalent of a 68 degree inclination.

The current TOPAZ/FIA Radar 5 orbital altitude of 1048 x 1057 km is slightly lower that that of the previous four TOPAZ/FIA Radar satellites, which orbit at ~1100 x 1110 km. However, it is not unlikely that over the coming weeks the orbit will be further raised to a similar altitude.

Unfortunately, I am now losing visibility of the object as the higher passes occur deeper and deeper in twilight.

TOPAZ-5 is the last of the block I TOPAZ payloads. The new 106.0 degree inclined orbital plane might be the new orbital plane for the block II payloads to be launched over the coming years.

Thursday, 11 January 2018

[Updated] A potential use for satellites in Zuma-like 50-degree inclined orbits



SpaceX's launch of the Zuma satellite on 8 January was interesting, and not just because of the ongoing saga of whether it failed or not (see a previous post).  

The odd 50-degree orbital inclination is another element that made this launch interesting (see discussion in my pre-launch post here: sightings of the Falcon 9 Upper Stage over Sudan after launch later confirmed this orbital inclination).

New ideas started to form post-launch after the Falcon 9 sightings from Sudan made me realize that while it indeed was launched into a 50-degree inclined orbit, the orbital altitude (900-1000 km apogee) was higher than I initially expected, making a proposed link to USA 276 unlikely.

And then @Cosmic_Penguin posted this small message thread on Twitter, referencing this interesting publication. That struck a chord and reinforced an emerging idea about a potential role for satellites in such 50-degree inclined, ~1000 km altitude orbits.

As @Cosmic_Penguin notes, the publication specifically discusses ~50-60 degree inclined, ~1000 km altitude orbits. And it is all about Space-based Radar.


I had just been looking into the coverage of the Zuma orbit, and it lines up with content in that report.

The map below is a ground coverage map of Zuma, would it have been alive and well. One of the uses of a ~50 degree inclined ~1000 km altitude Space Based Radar satellite mentioned in the report, is for shipping surveillance.

Indeed, a satellite in a Zuma-like orbit would basically cover all Ocean surfaces, except for the high Arctic and Antarctic, which are not that interesting for the purpose discussed below (moreover, the Arctic is extensively covered by groundbased and airborne radar).


click map to enlarge

A (Radar) satellite in this kind of orbit therefore would be very useful to keep track of illicit shipping movements on the High Seas.

Think stuff like embargo-runners, e.g. embargo-breaking shipments of coal and oil to for example North Korea, illegal weapons exports from North Korea, oil exports from Syria, illicit weapons transports to the Middle East, and human trafficking as well as drugs shipments.

Ships engaged in such illegal activities sometimes turn off their transponder, making it harder to track their whereabouts once out of sight of landbased shipping radar (see also the story about one particular embargo-breaking ship here). The classified US NOSS duo ELINT satellites and similar Chinese Yaogan triplets are meant to track ships from passive radiosignal crosslocation, but when a ship displays strict radio silence, these systems will not detect them either. But Space-Based Radar will.

Embargoes have become an important geopolitical tool when outright war is deemed not an alternative. We currently see embargoes enforced with regard to for example Syria and North Korea. Means to enforce embargoes including detecting and stopping potential embargo violations therefore have become important. Human trafficking and drugs trafficking are growing geopolitical problems as well.

So was Zuma meant to be an (experimental, i.e. a technology demonstrator) version of such a Space Based Radar for Ocean shipping surveillance? It is an option.

What might argue against it is the extreme secrecy surrounding the launch. Very few details were made public about the Zuma payload, the Agency operating it was not disclosed, and the launch was announced very late.

For all of this, explanations can be sought, but that admittedly all is "special pleading". For example, maybe the secrecy is there because the mission involves cutting edge experimental Radar technology. Or the secrecy could simply be the result of the "secrecy cult" in some parts of the US Government going over the top. Or it could point to operation by an Agency that wants to keep this operation on the down low - e.g. the CIA. And I can think of a few more - much more outlandish, which is why I won't mention them here - potential reasons.

We have seen this kind of secrecy before with PAN (and its later sister ship CLIO), with Prowler, and more recently with USA 276. All of these were experimental satellites doing unusual things: PAN roved between, snug up to and eavesdropped on commercial geostationary satellite telephony satellites. Prowler was an experiment for covertly inspecting other geostationary satellites on-orbit. And USA 276 remains mysterious but a series of very close encounters to the International Space Station suggest it might be a technology demonstrator for observing rendez-vous manoeuvres in space.

Zuma (the more so now it might have failed) also strongly brings the infamous USA 193 satellite to mind, although there we do know that it was a satellite for the NRO, and likely an experimental radar satellite [edit: see added note 2 below].

Nevermind what Zuma really was meant to be, and who was to operate it: the message to take home is that High Seas shipping surveillance is a potential and viable role to keep in mind for any future satellite launched in a ~1000 km altitude, ~50 degree inclined orbit.


Added note 1: Cosmic Penguin pointed out to me that this was also earlier brought up in a forum post by Ed Kyle.

Added note 2, 12 January 2018:  This article suggests Zuma might be an electro-optical/SAR hybrid and a follow-on to the infamous USA 193:

"Second, the Northrop Grumman satellite may be a follow-on to another failed satellite US 193. [...] ...., a source with direct knowledge of the program told me it was a blend of radar and electro-optical and would not provide any more detail than that. A source with wide knowledge of classified space programs has told me that the Northrop Grumman-built Zuma may be the next iteration of this. Both were apparently experimental satellites, in that they were not part of a large constellation of similar satellites."

Such a spacecraft would be well suited for the purpose indicated in this blog post.

Also, Northrop-Grumman, the company that built Zuma, has actually worked on developing ideas for Space Based GMTI Radar, which again would suit well to the purpose I suggest in this blog post.


Acknowledgement: Hat Tip to @Cosmic_Penguin on Twitter for putting ideas into my brain.

Wednesday, 20 January 2016

SIGINT, IMINT and MH17

(this post continues discussions in earlier posts on possible classified space-based observations of the shootdown of Malaysian Airlines flight MH17 over the Ukraine in 2014)

My position paper written for the Dutch Parliament Foreign Affairs committee hearing of Jan 22 (see my previous post) has a strong focus on infra-red detections of a missile by SBIRS. There are however a few other relevant aspects of Space Based observations in connection to the MH17 disaster that I could not cover in the space available to me for that paper.

In this post, I will provide some brief additional information about:

1) potential roles for IMINT satellites;
2) the positions of SIGINT satellites.


Optical and radar IMINT

1. optical IMINT

Both (unclassified) commercial and (classified) military satellite systems for high-resolution optical imagery (Image Intelligence, IMINT) exist, and both sources will be discussed below.

Optical and radar imagery obtained in the hours before, as well as during the event, might be used to look for missile systems, both on the Ukrainian as well as separatist sides of the front, in a wide circle around the site of the shootdown. It could also be used to verify the reconstruction of the purported movements of a Russian BUK system published by citizen journalist team Bellingcat, a study which is not uncontested. The Bellingcat team places the BUK in certain places at certain times, and if space-based imagery (either military or commercial) for those locations and times exist they could perhaps verify these claims.

The US military has one classified system of optical satellites with a (much-) better-than-1-meter capability: the KH-11 IMPROVED CRYSTAL/Evolved Enhanced CRYSTAL (aka 'Keyhole' or 'KENNAN') which reportedly (and theoretically, from known 2.4 meter mirror size specs) have a resolution in the order of  10-20 cm.

Mid-2014 this system consisted of four satellites: USA 161, USA 186, USA 224 and USA 245. All of these have been discussed on this blog before and are tracked by our amateur network.

We have accurate tracking data on three of these, USA 161, USA 224 and USA 245 for the days around 17 July 2014 and hence can pinpoint when these potentially had the crash area in their sight to better than a minute. For USA 186, which was actively manoeuvering around that time and for which we have a gap in our coverage form June to August 2014, pass times are a bit less certain and constrained to about 20-30 minutes accuracy.

First, we can positively affirm that one of the KH-11, USA 161 (2001-044A) actually had the Ukraine in its potential view during the incident at 13:20 UT:


click images to enlarge

Please note well: this does however NOT mean that USA 161 delivered imagery of the event. A number of factors should be taken into account:

1. the cloud cover at that moment, which might hinder imagery;
2. the crash site is located quite in the perifery of the satellites footprint area;
3. these satellites do likely not make images continuously, but only if commanded to do so, for specific areas of interest;
4. there is the question of whether USA 161 was still operational at that time. It was the oldest of the on-orbit KH-11, being launched 14 years earlier. Only a few months later it was de-orbitted, so it was clearly at the end of its lifetime.

In addition to their KH-11 system, the US military hires space on commercial high resolution optical IMINT satellites from the US commercial firm Digitalglobe (the same firm that supplies Google Earth with satellite imagery).  

Digitalglobe operates a number of satellites with a better-than-1-meter capability: Geoeye-1 (0.4 meter resolution), and Worldview 1, 2 and 3 (0.25-0.50 meter resolution). Most of the satellite imagery that the US Department of Defense supplies to the press (when briefing on the military situation in e.g. North Korea, Syria and Libya) comes from these commercial satellites.

Imagery from these same Digitalglobe satellites is also available commercially, to any interested party with money. And in addition to DigitalGlobe, the European company Airbus Defense and Space also offers commercial high-resolution optical imagery from its SPOT and Pléiades satellites. Pléiades 1A and 1B offer a 0.5 meter resolution. SPOT 5 and 6 offer a 2.5-1.5 meter resolution.

Accurate orbital data from non-classified sources are available for all the commercial imagers for 17 July 2014. The satellites in question made several daylight passes over the area in the morning of July 17, 2014, between 8:00 and 10:00 GMT, i.e. during the 3 to 5 hours before the shootdown, a period when the skies were still less clouded.

This does not mean that they necessarily made imagery of course. Yet any imagery these commercial Digitalglobe and Airbus satellites did make on July 16, 17 and 18 have the advantage that they are not "classified", unlike the US military data, meaning that they could be used and published without diplomatic problems by the Dutch government in the Dutch criminal investigation into the disaster.

I would therefore expect the Dutch OM to either buy or subpoena all potential Digitalglobe and Airbus imagery from these dates. They can be used to reconstruct missile system positions in the area (both on the Ukrainian, the separatist and Russian sides) within range of the shootdown location, and they can be used to hunt for missile transports (see my earlier remarks about the Bellingcat claims). The Dutch Air Force has an imagery analysis unit that is well suited to help with such an analysis. Including imagery from the days before and after the incident as well is useful to look for differences between imagery of these respective dates.


2. Radar IMINT

The US military has two systems for high resolution radar IMINT: the Lacrosse (ONYX) system of which currently only one satellite, Lacrosse 5 (2005-016A) is left on-orbit, and the radar component of the Future Imagery Architecture (known as TOPAZ), consisting of three satellites: FIA Radar 1, 2 and 3 (2010-046A, 2012-014A and 2013-072A). These systems should be capable of providing imagery with sub-meter resolutions, and like optical imagery, they can be used to look for the presence of missile systems in the area. They have the added bonus that they are not hampered by cloud cover, unlike optical imagery.

Apart from the USA, the German military also operates a radar satellite system, the SAR-Lupe satellites. The French military likewise operates its own radar satellite system, the Hélios system. Japan operates the IGS system (which includes both optical and radar satellite versions).

All of these satellites made passes over the Ukraine at one time or another on July 17 2014, so all of them might have provided useful imagery.  FIA Radar 3 made a pass right over the area in question near 11:43 UT for example, some 1.5 hours before the tragedy. FIA Radar 2 made a pass over the area at 18:00 UT, 4.5 hours after the shootdown. These are just a few examples.

Given what was happening in the area around this time, and the strong concern of NATO and the EU about this, it is almost certain that imagery of the area was collected by these US, German and French satellite systems.


SIGINT

My position paper briefly mentions that a number of countries have space-based SIGINT (Signals Intelligence) capacities. This does not only concern capacities for (for example) the NSA to tap into your cellphone and satellite telephone conversations: another important strategic aspect of space-based SIGINT is the capacity to detect radar and telemetry signals from enemy weapons systems. Such detections allow identification of the used weapons system (each system has its own 'signature'). They also allow, according to remarks by the then NRO director Bruce Carlson in a speech from September 2010 at the National Space Symposium, geolocation of the source of this radar signal (in the case of MH17: geolocation of the Target Acquisition Radar of the launch unit).

The US military has a number of SIGINT systems in several types of orbits: Low Earth Orbit (LEO) below 1500 km which allows coverage of a few minutes during a pass over a target; and Highly Elliptical Orbit (HEO) and geosynchronous orbit (GEO), which allow to monitor targets for many hours (HEO) to continuously (GEO) from distances of 36 000+ km.

France has a number of SIGINT satellites in LEO. China no doubt has SIGINT satellites too, as does Russia. For the moment I will focus on the US systems. I must ad that I did check the French systems as well but none of the French systems (ESSAIM and Elisa, both in LEO) had sight of the Ukraine at that time.

The US systems, under the catch-all codename ORION, include the TRUMPET-FO which move in HEO. One of them is USA 184, mentioned before in the discussion of SBIRS as it has a piggyback SBIRS capacity in addition to its main SIGINT role.

There are also the big MENTOR satellites in GEO, plus two MERCURY satellites also in GEO, and the older VORTEX system. Of these systems, TRUMPET-FO, MENTOR and MERCURY are certainly still active based on their orbital behaviour.

The map below shows the positions of those satellites in this series for which we have enough tracking data to allow a reconstruction of their positions and footprints on 17 July 2014, 13:20 UT and which had the MH17 crash area within potential view:


click map to enlarge

Again: this does NOT necessarily mean that all of these satellites were actively monitoring the Ukraine at that time. Quite a number of them will have been tasked on the Middle East.

Yet, given the strong NATO interest in events in the Ukraine at that time, notably the rising concern about advanced surface-to-air missile systems following the shootdown of a Ukrainian Antonov-26 a few days earlier, I would be surprised if none of them monitored the Ukraine at all.


A clarification note on the position of USA 184 (SIGINT/SBIRS)

In my position paper written for the Dutch Parliament Foreign Affairs committee meeting coming Friday, I included this map with the positions of three SBIRS satellites with view on the Ukraine at that time:


click map to enlarge

I should point out here that there is some leeway in the exact position of USA 184, depending on whether it made a corrective manoeuvre to maintain its Mean Motion of about 2.00615 revolutions/day or not since the day we last observed it.

If it did, its position would be slightly more westward compared to the position depicted above, i.e. in a position just north of Scotland rather than above the Norwegian coast:


Let me be clear: this does NOT influence the conclusions of my position paper: the MH17 crash site in both variants is well within the field of view as seen from USA 184, i.e. the satellite could potentially provide both Infra-red and SIGINT detections. In the interest of accuracy, I thought I should however mention it here.


Acknowledgement -  I thank Mike McCants (USA) and Ted Molczan (Canada) for discussions about satellite positions, notably concerning USA 184.