Testing a new lens for GEO and HEO (SamYang 2.0/135 mm)

The past week brought some clear skies. It also brougt me a new lens, a SamYang 2.0/135 mm ED UMC.

This lens had been on my wish-list for a while, as a potential replacement for the 1979-vintage Zeiss Jena Sonnar MC 2.8/180 mm I hitherto used for imaging faint Geosynchronous (GEO) and Highly Elliptical Orbit (HEO) objects, objects which are typically in the magnitude +10 to +14 range.

The 2.0/135 mm SamYang lens has gotten raving reviews on photography websites, several of these reviews noting that the optical quality of this lens is superior to that of a Canon 2.0/135L lens. And this while it retails at only half the price of an L-lens (it retails for about 460 to 500 Euro).

While I have the version with the Canon EF fitting, the SamYang lens is also available with fittings for various other camera brands.

Focussing is very smooth and easy with this lens. Unlike a Canon-L lens, the SamYang lens is fully manual (both focus and F-stop), but for astrophotography, manually focussing is mandatory anyway. The general build of the lens is solid. It is made of a combination of metal and plastic.

While not particularly lightweight, the lens is lighter in weight than my 1979-vintage Zeiss (which is all-metal and built like a tank, in true DDR fashion). The SamYang has a somewhat larger aperture (6.75 cm) than the Zeiss (6.42 cm), meaning it can image fainter objects. It also has a notably wider field of view (9 x 7 degrees, while the Zeiss has 7 x 5 degrees).

So for me, this seemed to be the ideal lens for GEO and HEO.

And after two test nights I can confirm: this SamYang lens indeed is spectacularly sharp. The first test images, made on January 15 and 16, have truely impressed me. Even at full F2.0 aperture, it is sharp from the center all the way to the edges and corners of the image.

Here is a comparison of the image center and the upper right corner of an image, at true pixel level. There is hardly any difference in sharpness:

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The images below, taken with the SamYang on a Canon EOS 80D, are crops of larger images, all but one at true pixel level.

The first image is a test image from January 15, a nice clear evening. It shows two objects in HEO: a Russian piece of space debris (a Breeze-M tank), and the classified American SIGINT satellite TRUMPET 1 (1994-026A). Note how sharp the trails are (this is a crop at true pixel level):

Click image to enlarge

The next night, January 16, I imaged several geostationary objects (which at my 51 degree north latitude are low in the sky, generally (well) below 30 degrees elevation). While the sky was reasonably clear, there were lingering aircraft contrails in the sky, locally producing some haze. Geostationary objects showed up well however, better than they generally did in the Zeiss images in the past.

The image below, which is a crop of a larger image, is not true pixel size, but slightly reduced in size to fit several objects in one image. It shows the Orion Nebula, several unclassified commercial GEO-sats, the Russian military comsat KOSMOS 2538 (BLAGOVEST 14L), and the classified Italian military communications satellite SICRAL 1B (2009-020A):

Click image to enlarge

The images below are all crops at true pixel level. The first one shows the US classified SIGINT satellite PAN/NEMESIS I (2009-047A), shadowing the commercial satellite telephony satellite YAHSAT 1B. It also shows a number of other unclassified commercial GEO-sats.

PAN/NEMESIS 1 is an NSA operated satellite that eavesdrops on commercial satellite telephony (see my 2016 article in The Space Review).

Note that this image - just like the next images- was taken at very low elevation, and from a light-polluted town center.

click image to enlarge

The image below shows another US classified SIGINT satellite, Mentor 4 (2009-001A), an ADVANCED ORION satellite. It shadows the commercial satellite telephony satellite THURAYA 2 (more backgrounds on this in my 2016 article in The Space Review). At magnitude +8, it is one of the brightest geosynchronous objects in the sky (note how it is much brighter than THURAYA 2):

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The last image below again is a classified US military SIGINT satellite, MERCURY 2 (1996-026A). While 24 years old it is, together with its even slightly older sibling MERCURY 1 (which I also imaged but is not in this image), probably still operational:

Click image to enlarge

After these two test nights, I am very enthusiastic about the SamYang lens. It is incredibly sharp, also in the corners, easy to focus, goes deep (in terms of faint objects), and overall performs excellent. I also like the wide field of view (compared to the 180 mm Zeiss which I previously used to target GEO). Together with the equally well performing SamYang 1.4/85 mm, it might be the ideal lens for imaging GEO and HEO.

Astrometric data on the targetted satellites from these test images are here and here. The astrometric solutions on the star backgrounds in the images had a standard deviation of about 2".

Added 20 Jan 2020:

This last image (reduced in resolution to fit) was taken this evening (20 January) and shows Trumpet 1 (1994-026A) passing the Pleiades:

Click image to enlarge

SIGINT Galore!

USA 136 (Trumpet 3), a TRUMPET in HEO. 28 Nov 2016
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The evening of 28 November was very clear - no moon and an extremely transparent sky, with temperatures around zero.

I used it to target several objects in GEO and HEO. Due to the favourable sky I could use exposure times twice as long as usual.

All the classified objects imaged were Signals Intelligence (SIGINT) satellites, i.e. eavesdropping satellites. The image above shows you one of the TRUMPET satellites, USA 136 (1997-068A), crossing through Andromeda. This is an object in a 63 degree inclined HEO orbit. The satellite was coming down from apogee at that moment and at an altitude of ~31 500 km.

Below is another object in HEO, USA 184 (2006-027A). This too is a SIGINT satellite, part of the TRUMPET-Follow On program (aka Advanced TRUMPET. It also serves as a SBIRS platform.

USA 184, a TRUMPET-FO in HEO, 28 Nov 2016
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This object was near apogee at this moment, at an altitude of 39 000 km over the Faroër Islands, which is why it looks stellar in this 20-second exposure. The star field is in Cassiopeia.

Both these objects hadn't been observed by our network for a while, hence they were somewhat off their predictions (1.5 degrees in position in the case of USA 136; and 1 degree off position in the case of USA 184).

I also briefly imaged a part of the geosynchronous belt, much lower in the sky. The targetted GEO objects were SIGINT satellites too: both Mercury 1 and Mercury 2 (1994-054A and 1996-026A), The Advanced ORION satellites Mentor 4 and Mentor 6 (2009-001A and 2012-034A) and the NEMESIS satellite PAN (2009-047A).

PAN and Mentor 4 (both shown below) have a story attached to them and were the subject of my recent article in The Space Review, which you can read here.

PAN (USA 207), a NEMESIS in GEO, 28 Nov 2016
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Mentor 4 (USA 202), an Advanced ORION in GEO, 28 Nov 2016
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A NEMESIS in the sky: PAN, Mentor 4 and close encounters of the SIGINT kind

I have published an article with the above title in The Space Review. Click here to read it.

Geostationary bonanza

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The images above and below are two small parts of one single image shot on May 2nd 2016, using a SamYang 1.4/85mm lens on a Canon EOS 60D with 30 seconds exposure (ISO 1000) under a very dark sky. These two image excerpts overlap in the corner: the upper right corner of the image excerpt above overlaps with the lower left corner of the image excerpt below.

Although both sub-images are only a few degrees wide, they show a bonanza of objects, including 3 classified objects.

In the image above, 11 objects including the classified SIGINT satellite PAN (2009-047A) are visible. PAN is parked next to the commercial communications satellite Yahsat 1B.

In the image below, 10 objects including two classified objects are visible: the two classified objects are the SIGINT satellite Mercury 1 (1994-054A), and the SIGINT satellite Mentor 4 (2009-001A), the latter parked next to the commercial communications satellite Thuraya 2.

The full 10 x 14 degree image, of which the images featured here are small excerpt parts, shows over 30 objects.

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Imaging Geostationary satellites, and PAN's past relocations

Last week saw some clear evenings, and I used one of them to image some geostationary satellites. It concerned "the usual suspects": MENTOR's, MERCURY's and the enigmatic, probably SIGINT satellite PAN (2009-047A). The latter satellite has not been moved for quite a while now: since the end of 2013 it is at longitude 47.7 E, parked close to a number of commercial comsats. In the past it was frequently relocated, taking positions next to various commercial COMSATS. In four years time between 2009-2013, it moved at least 9 times (which is a lot) to various longitudes between 33 E and 52.5 E.

PAN amidst several commercial COMSATS on 9 December 2015 (click to enlarge)

The diagram below charts these frequent movements of PAN. Relocations typically took place about once every 6 months. Late 2013, they stopped. PAN however must still be operational, as active station-keeping is necessary for it to stay at 47.7 E.

relocations of PAN over time, 2009-2015 (click to enlarge)

Four other SIGINT satellites and a military comsat were imaged as well: Mentor 4 (2009-001A) and Mentor 6 (2012-034A), Mercury 1 (1994-054A) and Mercury 2 (1996-026A), and the military comsat Milstar 5 (2002-001A).

Mentor 4, next to commercial comsat Thuraya 2 on 9 Dec 2015 (click to enlarge)

Mentor 6 and a number of commercial satellites, close to the Orion nebula, on 9 Dec 2015

Using the remote telescope at Warrumbungle (MPC Q65) in Australia, I recently (4 December 2015) also checked-up on the recently launched US Navy COMSAT MUOS 4 (2015-044A). It is still at its check-out location over the Pacific at longitude 172 W, but some recent press statements suggest check-out has been successfully completed, and it will be moved to its operational position at longitude 75 E near India in the spring of 2016.

A bounty of GEO satellites on June 21

The night of June 21-22 was clear, and as I had trouble sleeping, I decided to take the short bicycle trip to my secondary site, Cospar 4355. This site is located in the polder only just outside of town, but the sky is better there than at my regular site 4353, which is in the town center (the secondary site is about 2 km south of my regular site). As a result, I can use twice as long exposures, which means I can image fainter GEO satellites than from my regular site. The site, being in a polder, also has less horizon obstruction. Below is a panorama of the site, split up in two parts, each slightly larger than 180 degrees. Azimuth directions are indicated.

Panoramic view at Cospar 4355

I took some 54 picture (20 second exposures with a Canon EOS 60D + SamYang 1.4/85mm at 800 ISO) over the course of an hour. My main focus was on approximately 20-30 degree (1-2 camera fields) wide equatorial areas near azimuth 120-130 deg, 160 deg and 200 deg.

I captured a nice batch of objects: 17 classified objects, two Unknowns (initially four but two got ID-ed as classifieds) and A LOT of unclassified objects. The image in the top of this post shows an only 2.7 degree wide stretch of one image, and look how many objects are already in it.
One of the objects in the image, the defunct Russian military comsat Raduga 1-M1/Kosmos 2434 (2007-058A) was flaring repeatedly in subsequent images (compare also the two images in the top of this post).

The images below show two other swaths of sky only a few degrees wide. Various commercial GEO sats are visible, as well as two old Ariane r/b, of which several were captured this night:

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It also shows  the British military communications satellite Skynet 5B (2007-0056B).

One of the classified objects captured this night was AEHF 2 (USA 235, 2012-019A), part the new military communications satellite constellation that is gradually replacing the Milsat system. Another object imaged was the SBIRS GEO 2 (2013-011A) satellite, part of the new infra-red Early Warning constellation that is replacing the DSP constellation.

click images to enlarge

The lower of the two images above (it is slightly blurry because it is the edge of the image) also shows one of the initial UNID's of that night, "UNID 2", one that Cees and Ted later identified as the classified Italian military communications satellite Sicral 1 (2001-005A), which has recently been moved to 22 E.

Cees also managed to identify another UNID I imaged that night, "UNID 3":

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It is the object we amateur trackers designate as Unknown 130929 (2013-772A), an object in a Molniya orbit which was last seen 132 days before my observations (i.e. we temporarily "lost" it). It was over West Africa at an altitude of 1270 km at the time of observation, moving away from perigee:

Two other UNID's of this night remain to be identified. One of these ("UNID 1") appears to be in GTO: the other one ("UNID 4") appears to be in LEO and was very faint.

The image below shows two classified objects (plus several commercial geosats), both US Military communications satellites: USA 236 (2012-033A) and WGS 3 (2009-068A). WGS 3 is the third satellite in the Wideband Global Satcom constellation. USA 236 is a geostationary SDS data relay satellite. It is believed that they notably relay imagery of IMINT satellites in LEO, for example optical imageryby  KH-11 Keyhole/CRYSTAL and radar imagery by Lacrosse and FIA.

click image to enlarge

Mentor 4 and Thuraya 2 change of configuration

A change is occurring in the configuration of Mentor 4 (USA 202, 2009-001A), a huge Mentor /ORION SIGINT satellite, and the commercial communications satellite Thuraya 2. For over 3 years, Mentor 4 was stationed (as seen from my observing location) slightly south of Thuraya 2. On my June 21 imagery, it has moved to slightly North of Thuraya 2. Compare the top image from last June 21 with some images shot in previous years:

21 June 2014:

8 December 2010:

18 November 2012:

29 December 2013:

click images to enlarge

(The first image also shows the still unidentified UNID 1, likely in GTO, and  a classified r/b from another Mentor/ORION launch, Mentor 3 r/b (2003-041B)).

[UPDATED] Three UNID's in GEO/GTO/HEO/MEO, SBIRS GEO 2, and Lacrosse 5 has manoeuvered

Updated 14:35 UT (Jun 23) to reflect that I found a third UNID on my imagery after writing the original post

click image to enlarge

Saturday/Sunday night 21/22 June was very clear. As I had some trouble getting to sleep, I decided to make use of it to do a survey of the GEO belt, from my secondary site Cospar 4355 which is in the polder just outside of town, some 10-15 minutes by bicycle. The sky is a bit darker there and I have a better view to low elevations. Using the 1.4/85mm Samyang lens, I can expose twice as long as I can from my regular town center site 4353. The downside: so many objects on the images to identify and measure....

This observing site, in a polder park with meadows and polder ditches, is very tranquile. A choir of frogs was chanting during my observations, and meadow birds were adding their voice too. As I was observing, a low blanket of ground fog started to form, with my camera on tripod popping up just above it.


Two Three UNID's

At the moment I am still slowly working myself through the 54 images taken, identifying objects, but I can already report that I captured two three UNID objects (for positions on the 3rd see here), two in GTO/GEO and one in MEOor HEO. They are not in the Space-Track catalogue nor in our classified catalogue.

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UNID 1 was observed as a small trail on several images taken between 23:05:32 and 23:23:32 UT (June 21). The 15 second image above shows it near the SIGINT satellite Mentor 4 (2009-001A) and is the first image that captured it. It looks like something in GTO and a very cautious orbit fit to this short 18 minute observation arc indeed suggests a GTO-like, roughly 13160 x 36945 km, 12.8 degree inclined orbit with a period of ~1.6 revolutions per day:

UNID 1                                               13160 x 36945 km
1 00000U 00000X   14172.96808160 0.00000000  00000-0  00000+0 0    05
2 00000  12.7577 311.8608 3783132 187.8049 143.4679  1.55784798    00

click image to enlarge

UNID 2 was detected on only two 20 second images taken half a minute apart. It is less trail like (see image above), but slowly moving south when the measurements on the two images are combined. It is either in a somewhat inclined GEO orbit or a GTO object near apogee.

The image above also shows SBIRS GEO 2 (2013-011A), a classified geostationary SBIRS satellite (an Early Warning satellite looking for missile launches in Infra-Red). In addition, an old Russian r/b and a Russian military GLONASS (the Russian equivalent of GPS) satellite are visible. Star trails are slightly blurry because the FOV represents a detail near the edge of the image.

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[UPDATE] 
UNID 3 was detected close to alpha Serpens in only two 20 second images taken 1 minute apart.  It is clearly trailing. The positions fit either a circular MEO orbit, or a HEO orbit (the observation arc is too short to discriminate). Above, the two images that captured it are shown.


Lacrosse 5 appears to have manoeuvered

The same image that captured UNID 1 also captured the military Radar satellite Lacrosse 5 (2005-016A, see image in top of this post), just as it was emerging from Earth shadow. It was about 54 seconds late relative to 8-day-old elements. That is a lot for only 8 day old elements. Hence it appears to have manoeuvered somewhere in the past few days.

Open Question: Could US Military SIGINT satellites help to narrow down flight MH370's last location?

Please note: this post contains discussions of a highly speculative nature

Over the past days, it has become clear that the lost Malaysian Airlines flight MH370 has flown on for some 7 hours after contact was lost at 17:20 UT (March 7 UT, local March 8). This information comes from radio "ping-backs" of the aircraft's ACARS system received by the Inmarsat 3-F1 satellite, a geostationary communications satellite that is located at longitude 64 E over the Indian Ocean. These ping-backs were received hours after the last radio contact with the pilots and hours after the transponder was shut off, and indicate that the aircraft was still powered and 'alive' hours after it disappeared. A well written story at the CNN website gives backgrounds on the receptions and the system.

Position and footprint of Inmarsat 3-F1
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In this post, I will briefly summarize how Inmarsat 3-F1 detected the aircraft and determined a wide arc where the aircraft could have been at that time. I will then explore whether additional signal receipts by classified US Military Signals Intelligence (SIGINT) satellites might perhaps have been possible. If such additional receptions exist (an open question!) they would enable to further narrow down the location of the last ping-back.

That will largely be a theoretical exercise, as so far there has been no word that the US SIGINT satellite constellation did detect these ping-backs. This post therefore entails a clear element of speculation, and the central question remains an explicit open question.


Backgrounds: 'Marco Polo' between an aircraft and a satellite

Someone in the aircraft shut off the radar transponder beacon and the active ACARS messaging system near 17:20 UT. Yet this did not fully disable the ACARS system. The system kept answering periodic "pings" by the Inmarsat 3-F1 (1996-020A) satellite. These "pings", basically a kind of "Marco?" message,  are periodically sent out by the satellite and when received by the aircraft ACARS antenna, the aircraft pings back a brief "handshake" basically saying "Polo!". While such a handshake does not contain clear information about where the aircraft is when the active ACARS is disabled, it does contain the aircraft ID.

According to press reports, the last ping-back from flight MH370 was received 7 hours after the flight disappeared, near 00:11 UT on March 8. Apparently, only Inmarsat 3-F1 received these ping-backs.

From the time it took the radio-ping to travel from Inmarsat 3-F1 to the aircraft and then back again, the distance (but not direction) of the aircraft to the satellite can be determined. For example, at a radiowave speed of 300 000 km/s, a time difference of say 0.2 seconds between Inmarsat sending the ping and receiving the answer back, indicates the aircraft is at a distance of 30 000 km from the satellite.

Once you know the distance, you can draw a globe with that radius around the location of the Inmarsat satellite. Where that globe cuts the earth surface, it creates a circle, centred on the sub-satellite point. The aircraft must have been somewhere on that circle. This is basically how the wide arc that has been published was constructed, an arc which runs from Thailand to Kazakhstan in the north, and Indonesia to Australia and the Indian Ocean in the south. The aircraft could have been anywhere on that big arc, an area stretching thousands of kilometers.

To pinpoint the aircraft more accurately to a particular spot in the arc, one needs a detection by a second and preferably a third satellite.


Could US SIGINT satellites provide additional receptions for these pings?

One source of such additional ping-back signal receptions, in theory could be one of several Signals Intelligence (SIGINT) satellites employed by the US military. Please note that I say IN THEORY as the US government hasn't provided any statements that they did (which might indicate that they didn't). In other words: I am speculating on an open question here.

It depends on a lot of factors, not the least of which are questions whether these satellites were listening at the time, and whether they were monitoring the particular VHF/UHF radiofrequencies in question. Those are questions I do not have the answers to. What I will do, is discuss which US military satellites could potentially have received these ping-backs because they had coverage of the area.

1. The Mentor and Trumpet SIGINT satellites

Two US SIGINT systems in high orbits cover(ed) the relevant area: (1) several of the very large Mentor/Advanced Orion SIGINT satellites in geostationary orbit: and (2) one of the SBIRS/TRUMPET combined SIGINT and SBIRS satellites which moves in a Highly Elliptical Orbit and hovered high above the northern hemisphere at the time.

These SIGINT satellites serve to eavesdrop on radio communications including satellite- and mobile telephony, missile telemetry and signals from groundbased and airborne radar systems.

USA 184 TRUMPET imaged on 25 Aug 2009 by the author

 Mentor 4 imaged on 18 Nov 2012 by the author

The TRUMPET satellite in HEO which had coverage of (a part of) the area at that time is  USA 184 (2006-027A). The geostationary Mentor satellites covering the area are Mentor 1, 3, 4, 5 and 6 (1995-022A, 2003-041A, 2009-001A, 2010-063A and 2012-034A).

Position of various Mentor satellites and TRUMPET USA 184

Mentor satellite footprints

USA 184 area coverage and footprint detail
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2. NOSS (Naval Ocean Surveillance System) SIGINT satellites

Apart from the Mentor and Trumpet SIGINT satellites in high orbits, the US also operates a series of SIGINT satellites with accurate geolocalization capabilities in a Low Earth Orbit. It concerns the US Navy Naval Ocean Surveillance System (NOSS) satellites, of which there are several. They operate in close pairs, orbiting at an altitude of about 1000 x 1200 km in 63 degree inclined orbits. Their main purpose is to locate and track shipping through the radio communications of the latter.

A NOSS duo (NOSS 3-4) imaged by the author on 29 Jan 2011

Two duo's of NOSS satellites were covering the northern half of the area at the time of the last ping-back received by Inmarsat 3-F1: the NOSS 3-5 and NOSS 3-6 duo's (2011-014A and B and 2012-048A and P).

The NOSS 3-6 duo had the best coverage, which includes the full northern arc from Thailand to Kazakhstan determined by the Inmarsat reception:

click images to enlarge

position of the NOSS 3-5 and NOSS 3-6 duo at the time of the last pingback

in 3D: yellow arc is where the aircraft could be according to the Inmarsat 3-F1 reception

Chinese SIGINT

China operates a satellite system similar to the US NOSS, consisting of three satellite trio's in the Yaogan series (Yaogan 9A, B, C; 16A, B, C; 17A, B, C). None of these however had coverage of the relevant areas in the Indian Ocean, central Asia or southern Eurasia at that time.

Coverage summary

From the brief satellite coverage analysis summed up above, it seems that the northern overland arc from Thailand to Kazakhstan was potentially well covered by various US military SIGINT satellites: five Mentor satellites, a TRUMPET and a NOSS duo. The southern Indian Ocean arc is slightly less well covered (no TRUMPET or NOSS coverage) but was nevertheless in view of several geostationary Mentor SIGINT satellites.

The question now is: could one or more of these SIGINT satellites have captured the same ACARS ping-backs received by Inmarsat 3-F1? If so, the combination of their data with the Inmarsat data could potentially narrow down the last known position of the aircraft considerably.

It all depends on whether the satellites in question were actively listening at that time, and moreover, whether their monitoring includes the radio frequencies in which the ACARS ping-backs of flight MH370 operated. It perhaps also includes questions like whether any signals received are all kept on file, or if some selection is made and much deemed of no interest is directly discarded.

Those are some big serious "ifs", that I simply do not know the answers to: this stuff is, after all, classified. So far, the US government has not indicated that one of their SIGINT systems did capture the ping-backs. Which might mean that they didn't, as I can't imagine that they did not check for it.

Classified SIGINT satellite positions in this post (and previous posts) are based on orbits calculated by Mike McCants, based on amateur observations communicated on the SeeSat-L mailing list.

Addendum 18 March 2014:
In my initial analysis posted 17/03/2014, I forgot to include two other and older geostationary US SIGINT satellites: the two Mercury/ADVANCED VORTEX satellites that are located over East Africa.

 click images to enlarge

It concerns Mercury 1  (1994-054A) and Mercury 2 (1996-026A). Both satellites were recently moved to a new orbital position over East Africa and are station-keeping there, indicating they are operational. Their footprint includes the area of interest, although the southern Indian Ocean arc is close to the edge of their coverage.

Mercury 1 imaged by the author on 29 Dec 2013