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Unmanned Spaceflight.com _ Dawn _ Dawn Framing Camera Q&A

Posted by: pablogm1024 Jun 29 2011, 09:02 PM

Dear all,
We are amazed, and a bit flattered, by the interest that the Dawn mission has awaken throughout the internet and particularly in this forum, and we would like to thank you for it.

Space imagery is frequently subject of discussion and even re-work in these pages, but the field of space operations does not seem to be covered very often. That is why we have decided to offer you all the posibility to ask your questions to the team, that we will gladly reply within the limitations provided by our working agreements with JPL/NASA and the Dawn Science Team.

We would like to request in advance your understanding if we do not reply promptly (or not at all) to some of your questions. We are in a busy and exciting time, and we intend to share this excitement with you as much as we can.

Thank you all for making a great site out of UMSF and for your participation in this topic.

Regards,

Pablo Gutiérrez-Marqués
Framing Camera Operations Manager

Posted by: elakdawalla Jun 29 2011, 10:28 PM

Welcome, Pablo, we're absolutely delighted to have you here.

It's clear that the images of Vesta that you have posted so far have been enlarged, and I am sure they have been processed in other ways. Can you tell us a bit about how you are processing your images before sharing them with the public?

Posted by: Bunker9603 Jun 29 2011, 11:06 PM

Good question as I was wondering the same thing.

Rick

Posted by: pablogm1024 Jun 29 2011, 11:08 PM

QUOTE (elakdawalla @ Jun 29 2011, 11:28 PM) *
It's clear that the images of Vesta that you have posted so far have been enlarged, and I am sure they have been processed in other ways. Can you tell us a bit about how you are processing your images before sharing them with the public?

It is a well-known fact in this forum that heavily-pixelated images do not do great magazine covers. So in order to save the public the effort of squinting and turning the images around, we at MPS ( http://dawn.mpg.mpg.de ) applied an oversampling filter (like Lanczos) that removed most of the pixelation and provided more roundish features, like the ones might expect at Vesta.
Concerning the brightness, we have simply tried different stretching functions until we found one that showed the features that we intended to show.
However, the images released so far are not only the workings of the Framing Camera Team but also of the greater Dawn Team and some of them might have undergone a slightly different process.

Posted by: Fran Ontanaya Jun 30 2011, 12:57 AM

Hola, Pablo. Will you attempt to use superresolution on interesting targets?

Posted by: nprev Jun 30 2011, 01:28 AM

Pablo, no question, but MANY thanks for choosing to do so here on UMSF! smile.gif This is the sort of outreach that really works, and I think you'll find our reaction quite morale-boosting for the entire Dawn team. wink.gif

Posted by: Juramike Jun 30 2011, 02:41 AM

Hi Pablo! Thank again for posting here. Will your team be specifically planning images so that 3D anaglyphs are possible?

Posted by: pablogm1024 Jun 30 2011, 05:56 AM

QUOTE (Juramike @ Jun 30 2011, 03:41 AM) *
Hi Pablo! Thank again for posting here. Will your team be specifically planning images so that 3D anaglyphs are possible?

One of the primary scientific goals of the mission (see http://dawn.jpl.nasa.gov/mission/journal_09_27_10.asp ) is to create topographic maps. To this end, the Framing Camera will be pointing not only to nadir (downwards), but also at an angle so that a given spot is observed from different locations, providing stereo pairs (or triplets).
We do not know the particulars of when these topographic maps will be released, but I have no doubt that 3D anaglyphs will be part of them.

Posted by: hendric Jun 30 2011, 07:11 AM

Are there any plans for long-exposure imaging to find moons or rings?

Also, how does it feel to be "better than Hubble"? smile.gif

Posted by: pablogm1024 Jun 30 2011, 03:35 PM

QUOTE (hendric @ Jun 30 2011, 07:11 AM) *
Are there any plans for long-exposure imaging to find moons or rings?

Also, how does it feel to be "better than Hubble"? smile.gif

The presence of a moon around Vesta would have implications not only for science, but also for the safety of the mission. That is why a number of activities have been planned to detect moons if they exist.
With respect with the feeling of discovery, the sheer sight of an increasing number of pixels taking shape, revealing features that start to be familiar, is overwhelming, amazing, bewildering. It is a new OMG every occasion.
One day I was looking at the newly arrived images and, when my office mate asked me if he should fetch the rest of the team, all I could say was: "Give me just one minute to enjoy the images alone, and then you can get the team".

Posted by: paxdan Jun 30 2011, 04:03 PM

Do you have any special Kodak moments planned?

Posted by: Stu Jun 30 2011, 05:59 PM

QUOTE (pablogm1024 @ Jun 30 2011, 04:35 PM) *
One day I was looking at the newly arrived images and, when my office mate asked me if he should fetch the rest of the team, all I could say was: "Give me just one minute to enjoy the images alone, and then you can get the team".


I grinned from ear to ear when I read that. You are One of Us, no doubt about it. Welcome home! smile.gif

My initial questions:

1) Do you have any unofficial "working names" for the features you have seen on the images so far?

2) Has the team enjoyed how amateurs, like members of UMSF, have taken the raw images and turned them into animations, enhancing them, etc?

And thanks again for allowing us to grill you like this, it's a great idea and very good of you to take the time. smile.gif

Posted by: Greg Hullender Jul 1 2011, 01:21 AM

Yes, thank you very much!

Could you describe the team a bit? How many of you are there? What's a typical day's work like? No need for enormous detail (unless you feel like it) :-) but enough to let us frame our questions.

Thanks again!

--Greg

Posted by: pablogm1024 Jul 1 2011, 09:44 AM

QUOTE (Stu @ Jun 30 2011, 05:59 PM) *
1) Do you have any unofficial "working names" for the features you have seen on the images so far?

2) Has the team enjoyed how amateurs, like members of UMSF, have taken the raw images and turned them into animations, enhancing them, etc?

Hi Stu,
Thank you for your welcome. You also made me grin from ear to ear with your own post.

The naming assignment policy is very strict even within the Dawn Science Team. The 'C' word has been proscribed since we saw the first images of Vesta, but this will change soon. Of course, there are informal names that we have adopted with the Framing Camera team, but I'd rather post them here once the official ones have been published.

Concerning the work of the amateurs, we are simply amazed at the dedication you put into this hobby, and indeed we are considering getting in touch with some of the contributor to evaluate possible collaborations.

Posted by: pablogm1024 Jul 1 2011, 10:36 AM

QUOTE (Greg Hullender @ Jul 1 2011, 01:21 AM) *
Could you describe the team a bit? How many of you are there? What's a typical day's work like? No need for enormous detail (unless you feel like it) :-) but enough to let us frame our questions.

Hi Greg,
Thanks for your question.

The team has changed a lot during the project, from the time of conception to the present flight and data exploitation phase, even if we have tried to re-use the team members as much as possible. The team, which you can see in http://www.dawn.mps.mpg.de/index.php?id=2&L=1 , is divided basically in 5 groups:
- engineers, who worked in the project mostly during the hardware phase and are "in the back burner" in case we see hardware problems
- scientists, who determine what has to be observed, particularly timing, filter selection and exposure time, and do the science with the images
- operators, who take the scientists requests, turn them into flight commands, send them to JPL, get the image data when it is available and turn them into images for the scientists
- developers, who provide tools for the operators and scientists to do their work
- quality dept, who just cover our back, ensuring that, whatever we do, we leave a track that can be followed in case something goes wrong.

The daily work in this high phase currently involves 12 people approximately on the FC team alone.

There is not a typical day as such, because they vary a lot depending on the level of planning and flight activities, but I can briefly describe the workflow. It all starts with the greater Dawn Science Team laying out a general observation plan for a phase. The breakdown of the mission into phases and the scientific goals of each phase were agreed long time ago. With the observation plan and the operational allocations, the scientists pick a number of observations. Then the operators turn them into sequences that are tested first on the spare cameras, then on a spacecraft testbed, before they are sent for flight operations.
On the down-link side, the raw packets are received and stored at the Dawn Science Center (UCLA) and then forwarded to us for reconstruction of the uncalibrated and calibrated images. After that, it is all either science or PR, way beyond the understanding of this humble operations team.
Of course, on top of this is the daily work of developing and testing tools for processing and analyzing the data, and lots of management.

Posted by: pjam Jul 1 2011, 04:36 PM

Hallo and welcome, Pablo!

That post on Dawn FC team organization and activity is gold! Almost puts us there...
Good luck with the coming weeks & months, and thanks for volunteering to be the liasion.

...This is a good time to be alive!

-pjam

Posted by: hendric Jul 1 2011, 05:29 PM

Have you guys solved any interesting problems?

As an engineer myself, I like hearing about "war stories" from others. Once recent one for me was customers returning boards because they couldn't program the flash and it turned out that we had purchased these NAND flashes from brokers (kinda grey-market-ish), and when we scanned them, we found text strings like "Discovery Channel, Disney, etc". Apparently they were originally programmed for a set-top box and were remaindered, and our manufacturing program didn't erase them, because the spec for the NAND said they would come erased. Whoops!

Then there's the story about the chip that wouldn't boot properly the second time you powered it on, because a certain power rail decayed so slowly that 3 seconds after power off, it was still a couple of hundred millivolts, and when the processor turned on, it corrupted the internal state enough to cause a crash. That one was a real head-scratcher for me, first time I'd seen a problem caused by a power supply not powering down fast enough!

Posted by: ngunn Jul 2 2011, 08:24 AM

QUOTE (pablogm1024 @ Jul 1 2011, 10:44 AM) *
Concerning the work of the amateurs, we are simply amazed at the dedication you put into this hobby, and indeed we are considering getting in touch with some of the contributor to evaluate possible collaborations.


Seeing what's been happening with the latest image that looks like a very good idea. laugh.gif

Seriously, I'd like to add my heartfelt thanks to you for letting us all 'inside' the Dawn mission as far as your remit allows. I hope that the resulting positive experience on both sides will continue to move mission management towards a more Cassini-like image release policy.

Posted by: pablogm1024 Jul 2 2011, 09:43 PM

QUOTE (hendric @ Jul 1 2011, 05:29 PM) *
Have you guys solved any interesting problems?

It is a general rule of politeness, that one should not talk about the war while it is still going on, but since Marc Rayman, the mission engineer, already talked about it in http://dawn.jpl.nasa.gov/mission/journal_11_30_10.asp, I would like to call your attention about the intelligent solution that the mission team envisioned to save the propellent hydrazine.
Regards,
Pablo

Posted by: pablogm1024 Jul 2 2011, 09:49 PM

QUOTE (Fran Ontanaya @ Jun 30 2011, 12:57 AM) *
Hola, Pablo. Will you attempt to use superresolution on interesting targets?

Hola Fran
I am afraid that you question falls more on the side of scientific analysis software than on the operations, but I will try to answer it.
The observation plan for the http://dawn.jpl.nasa.gov/mission/journal_09_27_10.asp already includes several views of each spot from different angles, that can provide sub-pixel resolution on the topographic model. I hope this answers your question.
Regards,
Pablo

Posted by: Norm Hartnett Jul 2 2011, 10:00 PM

Ah, I see on the Dawn site that, in order to take Nav photos, the spacecraft has to stop thrusting. That would certainly explain the paltry number of pictures we have seen to date. Do you have a timeline of the number of Nav photo attempts planned for the next couple of weeks, Pablo?

Posted by: Phil Stooke Jul 2 2011, 10:04 PM

If I may borrow this space to reply to Fran, even if super-resolution is not a goal of an imaging sequence, there will be opportunities to use it every time a multispectral image sequence is obtained. If a set of images are taken in quick succession through different filters, they can be combined to make a super-resolution composite. I have done this with Voyager images of Hyperion, for example. If there is a lot of colour variation in a scene, as we see on Io, this will not work, but for scenes with only minor colour variation it will be OK, and that will be true for Vesta.

Phil

Posted by: pablogm1024 Jul 2 2011, 11:03 PM

QUOTE (Norm Hartnett @ Jul 2 2011, 10:00 PM) *
Do you have a timeline of the number of Nav photo attempts planned for the next couple of weeks, Pablo?

Hi Norm,
The plan for this approach phase was to start by acquiring OpNav images once per week for the first 6 weeks and then change to twice per week, which is the rate that we currently have.
Regards,
Pablo

Posted by: Fran Ontanaya Jul 3 2011, 03:21 AM

QUOTE (Phil Stooke @ Jul 2 2011, 11:04 PM) *
there will be opportunities to use it every time a multispectral image sequence is obtained.


Thanks. I wonder if the backup camera can be operated at the same time as the main, and if the team would get a waiver to do so at Ceres after the end of the primary mission.

Posted by: pablogm1024 Jul 4 2011, 10:10 AM

QUOTE (Fran Ontanaya @ Jul 3 2011, 03:21 AM) *
Thanks. I wonder if the backup camera can be operated at the same time as the main, and if the team would get a waiver to do so at Ceres after the end of the primary mission.

Hi Fran,
Yes, both cameras can operate concurrently and indeed, they have done so in the past... on ground. Currently there are no plans ot use both cameras concurrently and we have seen no reason to do so, but if you have a suggestions, please do not hesitate to speak up.
Regards,
Pablo

Posted by: Bjorn Jonsson Jul 4 2011, 01:43 PM

Welcome to UMSF!

I have a few questions:

How many images do you expect to obtain while orbiting Vesta? Are some/all of the images compressed aboard the spacecraft before they are downlinked and if so is the compression lossy or lossless?

QUOTE (pablogm1024 @ Jun 30 2011, 03:35 PM) *
One day I was looking at the newly arrived images and, when my office mate asked me if he should fetch the rest of the team, all I could say was: "Give me just one minute to enjoy the images alone, and then you can get the team".

This is a familar feeling to me in a slightly different context though. There's something special about seeing a 'new' world clearly for the first time.

Posted by: pablogm1024 Jul 5 2011, 09:59 AM

QUOTE (Bjorn Jonsson @ Jul 4 2011, 01:43 PM) *
Are some/all of the images compressed aboard the spacecraft before they are downlinked and if so is the compression lossy or lossless?

Hi Bjorn,
It is out of discussion that, once you launch a mission into space, you have already made the biggest expense, so the way to get a return for this is getting science of the data. The overall data volume transmitted from the spacecraft has a significant impact in the DSN usage costs, so try to minimize the volume as long as it does not impact the science quality. This is why all the images we transmit are compressed, but loss-less. Later in the mission, there will be phases were certain types of images will be considered sub-prime and will therefore be compressed with loss. These will be images intended to provide a background but not worthy from the science point of view.
Regards,
Pablo

Posted by: Fran Ontanaya Jul 7 2011, 02:58 PM

QUOTE (pablogm1024 @ Jul 4 2011, 11:10 AM) *
we have seen no reason to do so, but if you have a suggestions, please do not hesitate to speak up.


Perhaps to add them if a longer single exposure would suffer from smear.

Another question: is there a priority to capture and download first certain filters? Particulary clear, versus the ones more suitable for RGB, versus the ones suitable for trippy science color. laugh.gif

Posted by: pablogm1024 Jul 9 2011, 10:30 PM

QUOTE (Fran Ontanaya @ Jul 7 2011, 02:58 PM) *
Another question: is there a priority to capture and download first certain filters? Particulary clear, versus the ones more suitable for RGB, versus the ones suitable for trippy science color. laugh.gif

Yes, the camera implements a download priority scheme in four levels. The top priority is given to images acquired for the purpose of optical navigation (OpNav), like most of the images that we are acquiring now during the approach phase. The other three priorities are assigned to the different image acquisition depending on the purpose of a particular observation.

To all:
I am now on vacation in Spain, so I have limited access to internet. Please be patient in case it takes me a couple of days to answer your questions.

Posted by: Greg Hullender Jul 9 2011, 10:39 PM

How long does the camera take to make a picture?

--Greg

Posted by: MahFL Jul 11 2011, 02:09 PM

QUOTE (pablogm1024 @ Jul 9 2011, 11:30 PM) *
To all:
I am now on vacation in Spain, so I have limited access to internet. Please be patient in case it takes me a couple of days to answer your questions.



He went on vacation during approach ?........ rolleyes.gif

Posted by: Stu Jul 11 2011, 02:56 PM

Hey, everyone needs a holiday.

Have a great hol Pab. I hope you're taking *loads* of pictures... laugh.gif

Posted by: centsworth_II Jul 11 2011, 06:09 PM

QUOTE (MahFL @ Jul 11 2011, 10:09 AM) *
He went on vacation during approach ?
There is no end to the advantages of ion propulsion! laugh.gif

Posted by: hendric Jul 11 2011, 06:53 PM

It's not like the approach is an immediate thing. They're only taking photos two days a week as well. Once they get into orbit, I think his schedule is going to be busy for quite some time. Now is probably the perfect time to take a quick vacation before it gets real busy!

Posted by: djellison Jul 11 2011, 09:34 PM

QUOTE (MahFL @ Jul 11 2011, 07:09 AM) *
He went on vacation during approach ?........ rolleyes.gif


Would you rather he took it during the year long Vesta encounter....or would you rather he just went without a vacation for 18 months?

Posted by: Greg Hullender Jul 12 2011, 03:38 AM

QUOTE (pablogm1024 @ Jul 9 2011, 03:30 PM) *
I am now on vacation in Spain, so I have limited access to internet. Please be patient in case it takes me a couple of days to answer your questions.

Have a good time, and be sure to send us pictures!

--Greg (I couldn't resist) :-)

Posted by: pablogm1024 Jul 13 2011, 09:26 AM

QUOTE (Greg Hullender @ Jul 9 2011, 10:39 PM) *
How long does the camera take to make a picture?

--Greg

Hi Greg,
The camera takes about 5 seconds plus exposure time to acquire an image when we command single shots. We have a batch mode were several image are taken with one command, and there we can get down to about 1 image every 3.5 seconds.
Concerning the exposure times, we are currently in the order of 10 ms for the clear filter and between 150 and 1200 ms for the color filters, where we have varying sensitivity.

Posted by: pablogm1024 Jul 13 2011, 09:38 AM

QUOTE (hendric @ Jul 11 2011, 06:53 PM) *
It's not like the approach is an immediate thing. They're only taking photos two days a week as well. Once they get into orbit, I think his schedule is going to be busy for quite some time. Now is probably the perfect time to take a quick vacation before it gets real busy!

You got it right! My vacation duty cycle these days is about 23/24, while I still work 1/24 of my time. That is the advantage of networks these days. I still get promptly informed if something goes wrong or if new images hit the ground! I have also taken great care to train someone else to take after me.

Posted by: Toma B Jul 13 2011, 10:34 AM

QUOTE (pablogm1024 @ Jul 13 2011, 11:26 AM) *
... ...color filters... ...

When can we expect to see first Vesta's color image?
Can this be even close to "True color"?

Posted by: pablogm1024 Jul 21 2011, 08:14 AM

Starting Friday, I will be back on duty providing on-site Operations support in the LA area. In case someone would like to get first hand impressions of what Operations mean, please speak up. Otherwise, see you all, Vesta connoisseurs, at the Vesta Fiesta.

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