Printable Version of Topic

Posted by: neo56 May 12 2021, 03:48 PM

My take on this awesome shot of Ingenuity in front of two distant dust devils, and in animation.

https://flic.kr/p/2kY3JUi

Posted by: neo56 May 14 2021, 09:10 PM

A very beautiful dust devil was recorded by Mastcam-Z Right in the sequence of the 5th flight of Ingenuity.
Substracting MCZ frames by a frame without the dust devil makes it more visible.

https://flic.kr/p/2kYBCYs

Posted by: Andreas Plesch May 17 2021, 12:29 AM

Another day, another devil in dust alley:

(preview does not seem to play, click to animate)

https://mars.nasa.gov/mars2020-raw-images/pub/ods/surface/sol/00084/ids/edr/browse/ncam/NLF_0084_0674398274_190ECM_N0032430NCAM00500_01_295J01.png

Posted by: PDP8E May 20 2021, 02:08 AM

a little late with this ... I just saw Andreas post this as well - post #54
Here is a gif of the best frame of the dust devil on Sol 84

Posted by: Phil Stooke May 25 2021, 06:42 AM

Dust devil alert! (yes, another one). Sol 92, just about due west, right side of this image (NLF_0092_0675115622_792EBY_N0040136NCAM00698_00_0LLJ01_800).

Phil

Posted by: charborob May 25 2021, 11:40 AM

Sol 92 LMastcam-Z, with a dust devil in the upper left corner:

Posted by: PDP8E May 26 2021, 12:03 AM

Since this place looks like Dust Devil Alley... I wrote a little workflow program to look for them in the NAV sequences

This is SOL 84 ... (we've seen this --- eyes left) ... the gain is cranked in the program

This is Sol 78 ... The program found a near-invisible DD



(The blues are darker areas that change color before they are gained... it's a work in progress

Posted by: neo56 May 26 2021, 07:29 PM

The nice dust devil of sol 92 captured by MCZ-Right, contrast enhanced:

https://flic.kr/p/2m1PbV5

And an animation:

Posted by: Andreas Plesch Jun 3 2021, 08:48 PM

Another set of images captured by Hazcam and Navcam of one or possibly two dust devils, a good two minutes apart, on sol 102, in the favored spot, in front of the darker crater wall:

Posted by: PDP8E Jun 6 2021, 03:46 AM

Here is a GIF of 21 images (NAVCAM LEFT) for 5 minutes around local noon on Sol 101
It is from a program that looks for dust devils
Short Story: there are none close by (but there is something going on on top of the deltas in the center)
With the gain turned all the way up -- I suspect I am seeing compression artifacts, exposure differences, sensor sensitivities

Posted by: PDP8E Jun 8 2021, 01:53 AM

Sol 100 Dust Devil Program
21 image GIF - NAVCAM-LEFT - 5min starting at 2:15 pm local

(1) left of center on top of a delta
(2) right of center in front of the deltas (speedy)

Posted by: Andreas Plesch Jun 9 2021, 02:14 PM

A more stationary dust swirl on the center of the delta, on sol 107:

Click to animate. The frame spacing is about 14s but played at 0.5s for dramatic effect.

quickest workflow:

- filter raw images to select frames as specifically as possible.
- use bookmarklet to extract list of raw image urls
- copy list and paste as wget arguments on console to download, remove urls if necessary
- optionally enhance images with gimp or imagemagick
- upload images to ezgif.com
- use ezgif to crop, enhance, label and optimize animated gif
- download from ezgif.

Posted by: PDP8E Jun 9 2021, 04:35 PM

Sol 107 Dust Devil Watch
Finer details still elude the detector so far ... but that delta is far away!
5 minute GIF starting 1:15pm local time
Scintillating bits are compression/stretching (?) or real (?)

Posted by: PDP8E Jun 13 2021, 08:29 PM

Sol 111 -- Dust Devil Watch
Probable: One very far DD -- far left on the top of the crater rim - persists over several frames
Otherwise not much else
Gain all the way up - and then some - (very scintillating!)
GIF

Posted by: vikingmars Jun 17 2021, 02:09 AM

Sol 114: a big dust devil was passing close to the rover

Posted by: nprev Jun 19 2021, 12:05 AM

Hey, all. At the suggestion of long-time member PDP8E this thread has been created for everybody to post their images and animations of dust devils observed by Perseverance. Please be sure to include the sols when taken and times as well if they're available to make this data (and your great work) as useful as possible for any researchers who may take an interest. Thanks!

EDIT: I'll be moving several posts from the Perseverance threads over here to kick it off.

Posted by: PDP8E Jun 19 2021, 03:42 AM

SOL 35 -- 1:20PM local
3 frame segment of a 360 degree quick peek (no DDs in the other frames)
Facing SW, the landing site is in the center, Kodiak is to the right.

Posted by: neo56 Jun 19 2021, 09:52 AM

A larger field of view including Kodiak hill showing the dust devil mentioned by Olivier:

https://flic.kr/p/2m6j2x6

Contrast increased:
https://flic.kr/p/2m6j5Pr

And another dust devil, again on sol 114:

https://flic.kr/p/2m6semx

Posted by: PDP8E Jun 19 2021, 05:06 PM

SOL 117
WOW -- No fancy detector required!
It is more of a GUST than a DD...

Posted by: tau Jun 23 2021, 07:26 PM

Two dust devils on sol 120 in a difference image.
The right one (black here because negative) was photographed at 13:40:26 local mean solar time,
the left one (white because positive) at 13:49:45. Its continuation into the sky is faintly visible.

Posted by: HSchirmer Jun 26 2021, 10:41 PM

Hmm, time to start naming the dust devils after the members of the band Kansas, perhaps after cities in Kansas, and crowd-sourcing a competition to see which Kansas grade school can count the most?

Dust In The Wind.
https://youtu.be/tH2w6Oxx0kQ

Posted by: PDP8E Jun 29 2021, 01:45 AM

SOL 121 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances)
GIF

Posted by: PDP8E Jun 29 2021, 11:42 PM

SOL 123 Dust Devil Watch
21 Frames -- stationary stance -- 1PM local -- 14 secs between images -- 4 minute span
GIF

... the detector still has issues with the DD parts in the Sky ...

Posted by: PDP8E Jun 30 2021, 02:24 AM

SOL 127 Dust Devil Watch (not 128)
360 degree quick peek (3 frames each in 5 stances) -- 3:20 PM local
GIF

edit 06-30-2021 -- fixed SOL # from 128 tp 127 -- oops -- reloaded GIF

Posted by: PDP8E Jun 30 2021, 10:26 PM

SOL 128 Dust Devil Watch
21 Frames -- stationary stance -- 11 AM local -- all quiet (only compression and sensor noise)
GIF

Posted by: Ryan Kinnett Jul 1 2021, 01:45 AM

(I posted this initially to the EDL thread but can't seem to find it now, so here it is for posterity)

Perseverance recorded this DD during descent. Simeon Schmauss spotted this in LCAM footage and produced this stabilized and reprojected view, shown here at 20x real time. The DD is seen moving westward at roughly 8.5 m/s (20 mph) and was estimated to be about 25 m (75 ft) wide.

https://twitter.com/stim3on/status/1379575241970683908?s=20

Posted by: Ryan Kinnett Jul 1 2021, 02:11 AM

Note the dark streak seen in the crater floor between the prominent foreground peninsula and the background peninsula. That got me and Simeon looking at HiRISE views of this area to see if that might be a transient feature, maybe a DD track. Sure enough, that track was visible in the first HiRISE view after Perseverance's arrival but was not present just six months earlier. That track is ~34m wide.



Across this broader HiRISE swath you can see dozens or hundreds of similar transient streaks, some estimated to be ~80m wide, predominantly oriented east/west.



This place is a popular playground for these devils!

Posted by: PDP8E Jul 1 2021, 06:15 PM

Hi Ryan,
Thanks for those DD maps!
And a personal thank you for the RoverPics website over on github. Great Job!
Karle

Posted by: PDP8E Jul 6 2021, 02:38 AM

SOL 132 - Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 2:30 PM local
Improved noise reduction
Only one DD found - pretty quiet
GIF

Posted by: PDP8E Jul 6 2021, 08:59 PM

SOL 134 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 8:45 AM local (early...)
Improved noise reduction
All quiet ... The mid-morning sun angle and lighting is interesting
GIF

Posted by: PDP8E Jul 10 2021, 07:01 PM

SOL 137 Dust Devil Watch
21 Frames -- stationary stance -- 5:00 PM local
A new version of the detector - noise reduction / refined structure

A nice DD in the distance ----<oops see post #33>----
GIF

Posted by: PDP8E Jul 13 2021, 11:12 PM

SOL 140 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 2:30 PM local

Nice DD in the SW stance (4th set)
GIF

Posted by: PDP8E Jul 14 2021, 02:09 AM

on SOL 137 my dust devil detector was TRICKED!
I was checking the location of the SOL 137 'dust devil' and it wasn't there!

The sequence of 21 images was 5 minutes and 23 seconds starting at 17:05:27 PM (late in the day... long shadows)
Here is the first and last image in a GIF

The detector dilates the area around initial image differences and made it larger....
< see post #31>

Posted by: Phil Stooke Jul 14 2021, 03:22 AM

I don't think this one was mentioned before: on sol 129 the Navcams caught a DD against the crater wall to the SW:

https://mars.nasa.gov/mars2020-raw-images/pub/ods/surface/sol/00129/ids/edr/browse/ncam/NLF_0129_0678403356_559ECM_N0042222NCAM03129_04_195J01_800.jpg



Phil

Posted by: PDP8E Jul 15 2021, 09:45 PM

SOL 142 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 3:45 PM local
Looks like the same place as SOL 140
Very Quiet (I turned down the denoise knob just to see if it is that quiet... it is)
GIF

Posted by: PDP8E Jul 17 2021, 04:10 PM

SOL 144 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 10:30 AM local
All Quiet
GIF

Posted by: PDP8E Jul 18 2021, 04:29 PM

SOL 145 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 4:30 PM local
All Quiet -- Late in the day. -- NO DDs

abbreviated GIF

Posted by: PDP8E Jul 19 2021, 10:17 PM

SOL 146 Dust Devil Watch
21 Frames -- stationary stance -- 3:00 PM local
ACTIVE -- a brief surface dust-gust in the center -- a strong gust on the right that blows into a type of dd?
GIF

Posted by: PDP8E Jul 21 2021, 10:23 PM

SOL 147 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) --3:45 PM local
Quiet -- NO DDs -- Abbreviated GIF

Posted by: PDP8E Jul 21 2021, 10:26 PM

SOL 148 Dust Devil Watch
21 Frames -- stationary stance -- Noon local
VERY ACTIVE -- EIGHT DDs
GIF

... I hope Ingenuity survived...

Posted by: PDP8E Jul 22 2021, 10:25 PM

REVISED SOL 148
I revved the program to move it into HSV color space (RGB is not intuitive for saturation and luminance)
The dust devils are now the correct Hue (with the brightness turned up just 33%)
It also kills the annoying scintillation from the noise and compression artifacts.

Posted by: PDP8E Jul 23 2021, 02:46 AM

Detecting Dust Devils with multiple images is fairly straightforward: average all the frames, and compare each image to the average -- use subtract, ratio, and other techniques.
Detecting faint DDs in one image requires a different approach: increase the contrast while retaining the image quality-- somehow.
This is a test image from SOL 15 (!). The technique is Stochastic Equalization / Adaptive Contrast (SEAC)
The image has a pronounced screendoor effect from the Bayer (in the sky) and has an overall 'old-timey postcard quality', but the DD is visible and the contrast is increased
Another image 30 minutes before had no artifact at this position.
--GIF

Posted by: tau Jul 23 2021, 04:46 PM

A storyboard for the dust devils from sol 148 (because the animated gif is too big for upload).

The difference between each image and the median of all 21 images is enlarged and then added to the median.
Since compression artifacts give large color blobs in the sky, I desaturated the sky.
The time markers start with the first image which was aquired at the local mean solar time of 12:01:50.

The large dust devil to the right of center in the first images seems to be quite close, because it casts a large shadow on the dune field in the foreground.
Later, the swirling dust around the brighter central column darkens the sky a bit.

Posted by: Phil Stooke Jul 23 2021, 07:20 PM

That is an excellent presentation of the complex events on that sol. Thanks for posting it!

Phil

Posted by: PDP8E Jul 23 2021, 09:19 PM

Tau, awesome work! (I hear you on the size issue!)

Posted by: tau Jul 23 2021, 09:46 PM

Some very faint dust devils are even better visible in the difference images.
The images are converted to gray scale to remove amplified color noise.
From 0 min 43 sec to 1 min 26 sec I can count seven dust devils active at the same time.

Posted by: PDP8E Jul 25 2021, 05:54 PM

Another view of the SOL 148 Event
Annotated -- 9 dust devils and a few gusts.
The event is 5 minutes long and we have 21 seconds of images.

Posted by: PDP8E Jul 26 2021, 01:05 AM

SOL 151 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) --1:45 PM local
Several DD's

Posted by: monty python Jul 26 2021, 06:07 AM

This is amazing. Anybody want to build a wind farm on mars? Poor insight lander.

Posted by: neo56 Jul 26 2021, 06:33 PM

Really nice dust devils on sol 151.

Posted by: PDP8E Jul 27 2021, 12:00 AM

SOL 153 Dust Devil Watch
21 Frames - single stance -- 11:55 AM local

One interesting DD -- it starts late -- wait for it! (center)
Another on the far left

Posted by: Andreas Plesch Jul 27 2021, 01:17 PM

I really appreciate those animations. From memory this seems the most active 5 minutes observed so far in the area. Also, probably the clearest example of dust devils moving in opposite directions, simultaneously, perhaps hinting at local rotating 'supercells' spawning those turbulences.

Posted by: PDP8E Jul 27 2021, 10:47 PM

SOL 154 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 12:30 PM local
DD's in the 4th and 5th sets

Posted by: PDP8E Jul 28 2021, 08:53 PM

SOL 153 -- NAV - 2:51 PM local
There is a right-left pair if someone wants to try an anaglyph

Posted by: PDP8E Jul 29 2021, 11:57 PM

SOL 156 Dust Devil Watch
21 Frames - single stance -- 12:15 PM local

Two DDs on the left will blow out-- BUT at the end, a crisp DD strolls in on the far right

Posted by: PDP8E Jul 30 2021, 08:25 PM

SOL 157 -- NAVR - 2:30 PM local
There is part of a right-left NAV pair

Posted by: PDP8E Aug 2 2021, 01:19 AM

SOL 151 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 3:20 PM local
Only two stances with DD and gusts
GIF

Posted by: PDP8E Aug 8 2021, 08:07 PM

I finished up some improvements on the DD detector (C++) and tried it out on the SOL 148 Event.
Since this sequence was taken at High Noon at Jezero, there are no long shadows from the actual 'wispy' DDs.
So, I think the dark triangular 'mat' at the beginning is low flying dust flung from the passing DD. As the dust settles it takes on the color of the ground.
Light colors are more positive image pixels than the Averaged Comparison Image (21 frames), darks are more negative pixels
The program is fully automatic: drop the images in the working directory, press the button, and a minute later its is all done.
I believe a lot more hand processing would suss out more detail and make it more photorealistic.
I included the actual vs processed images as a comparison -- a little extra compression made it all fit into the upload limit.
GIF

Posted by: PDP8E Aug 9 2021, 03:10 AM

SOL 166 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 12:30 PM local
Only one stance with DD
GIF

( I think the Rover team may be using greyscale to save image download bandwidth (?) )

Posted by: atomoid Aug 11 2021, 08:48 PM

Stereo (parallel) view attempt for DD https://mars.nasa.gov/mars2020/multimedia/raw-images/NRF_0157_0680885377_854ECM_N0060000NCAM03157_01_195J
..no parallax for make benefit stereo so subsequent bribe of glorious 'turtle' to pose foreground!

Posted by: PDP8E Aug 12 2021, 04:23 PM

Atomoid -A glorious turtle indeed!

SOL 169 - 21 image Dust Devil Watch -- 4:15 PM Local
NO DDs.
This is the single 'averaged' image:

Posted by: PDP8E Aug 13 2021, 08:27 PM

SOL 170 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 3:45 PM local
No DDs but the terrain is interesting
GIF

Posted by: PDP8E Aug 14 2021, 08:51 PM

SOL 172 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 5:05 PM local
No DDs -- late in the day... nice lighting
GIF

Posted by: PDP8E Aug 16 2021, 09:27 PM

SOL 173 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 12:30 PM local

Distant Gust in Stance 3
Very close Gust in Stance 5
GIF

Posted by: PDP8E Aug 17 2021, 10:08 PM

SOL 174 - "30" image Dust Devil Watch -- 11:15 to 11:40 AM Local
ACTIVE

There is a 30 frame sub-frame sequence
and a 15 frame full-frame sequence

30 frame:

(full frame is too big and basically the same thing)

Posted by: PDP8E Aug 18 2021, 01:17 AM

Yet another DD watch on Sol 174

SOL 174 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) --11:45 AM local

Gust in Stance 5
GIF

Posted by: PDP8E Aug 18 2021, 10:35 PM

Re-processed SOL 173 DD
Increased the sensitivity for dark matter.
3 stances ...
* the first stance shows a distant event with dust flying
* the middle stance shows an increase of dust right before the NAV camera head swivels to the next stance
* The final sequence picks up the action -- gust? or DD off-camera??
GIF

Posted by: PDP8E Aug 20 2021, 12:02 AM

SOL 175 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 12:50 PM local
No DD

Posted by: PDP8E Aug 20 2021, 12:04 AM

SOL 176 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 12:20 PM local
No DD - odd angle

Posted by: PaulH51 Aug 20 2021, 05:49 AM

19.35 degrees (from JSON)

Posted by: vikingmars Aug 21 2021, 06:57 AM

Sol 178: dust devils spotted at the left of NavCam images
https://mars.nasa.gov/mars2020-raw-images/pub/ods/surface/sol/00178/ids/edr/browse/ncam/NRF_0178_0682754853_667ECM_N0062666NCAM02178_01_195J01.png
https://mars.nasa.gov/mars2020-raw-images/pub/ods/surface/sol/00178/ids/edr/browse/ncam/NLF_0178_0682754853_667ECM_N0062666NCAM02178_01_195J01.png

Posted by: PDP8E Aug 22 2021, 04:30 PM

SOL 178 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 12:05 PM local
No DD - as we trundle down the service road between the ridge and the dunes ...

Posted by: PDP8E Aug 22 2021, 05:44 PM

SOL 179 - 21 images (4 seconds apart) not sure why...
No DD ... looking at the ridge...

Posted by: PDP8E Aug 23 2021, 10:22 PM

SOL 178 - 3:54 PM Local
rechecking images
there is a second fainter DD to the left of the 'visible' one that VikingMars pointed out... (and clouds too)
GIF

Posted by: PDP8E Aug 25 2021, 12:49 AM

It's a two-for-one day!

DD Watch on SOL 181
360 degree quick peek (3 frames each in 5 stances) -- one in the morning and one at noon

Three DDs in Stance 5 (on the noon watch)

NOON is TOP
MORNING is BOTTOM

Posted by: PDP8E Aug 25 2021, 03:38 PM

SOL 182 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 1:09 PM local

* Probable Distant DD in Stance 2 (a quarter of the way in from the left, against a distant hill)
* DD in Stance 5 to the left also

Posted by: PDP8E Aug 26 2021, 10:26 PM

SOL 183 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 1:25 PM local

* Stance 1 -- Distant DD on the far right -- to the left of the horizon hills
* Stance 2 -- Distant DDs on the left -- picking up the DD action from Stance 1
* Stance 4 -- Distant DD in the hills

Posted by: PDP8E Aug 27 2021, 10:03 PM

SOL 184 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 1:00 PM local

Stance 1 -- minor but real wind disturbance -- far-left
Stance 3 -- small DDs -- far-left and far-right
Stance 4 -- well-formed DD

Posted by: PDP8E Aug 29 2021, 03:28 PM

SOL 186 - 21 Images - 1 Stance
All Quiet -- Nice view

Posted by: PDP8E Aug 31 2021, 08:41 PM

SOL 188 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 2:35 PM local
All Quiet -- detector gain noise

Posted by: PDP8E Sep 2 2021, 08:59 PM

SOL 189 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) --4:45 PM local
All Quiet -- Stance 5 has an exposure timing diff due to facing the late afternoon Sun

Posted by: PDP8E Sep 6 2021, 10:04 PM

SOL 191 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) --4:40 PM local
All Quiet

Posted by: PDP8E Sep 6 2021, 10:06 PM

SOL 193 (A) - Dust Devil Watch
21 Images - 1 Stance -3:05 PM
All Quiet

the first of 2 DD watches that day

Posted by: PDP8E Sep 6 2021, 10:09 PM

SOL 193 (b ) Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 3:10 PM local
Stance 4 has a DD climbing the crater rim

(the 2nd DD watch on SOL 193)

Posted by: PDP8E Sep 12 2021, 02:57 AM

SOL 197 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 11:30 AM local

Stance 1 -- DD far left
Stance 2 -- Two distant DD's, center
Stance 5 -- DD far right

Posted by: PDP8E Sep 14 2021, 02:25 AM

SOL 200 - Dust Devil Watch
21 Images -- 1 Stance -- 4:30 PM (late in the day)
All Quiet

Posted by: PDP8E Sep 14 2021, 09:00 PM

SOL 202 - Dust Devil Watch
21 Images -- 1 Stance -- 3:20 PM
All Quiet

Posted by: PDP8E Sep 16 2021, 09:55 PM

SOL 203 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 3:05 PM local

Stance 4 -- well-formed twister center-left

Posted by: PDP8E Sep 16 2021, 11:45 PM

SOL 204 Dust Devil Watch
The Nav Cam caught this DD at 2:30 PM
(It is part of a Left/Right pair)

Posted by: HSchirmer Sep 18 2021, 04:28 AM

Quick FYI- new paper on Dust Devils...

Vortices and Dust Devils As Observed by the MEDA Instruments onboard Mars 2020 Perseverance Rover
https://arxiv.org/abs/2109.04601

Posted by: PDP8E Sep 21 2021, 09:38 PM

SOL 208 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 1:40 PM local

Stance 3 -- DD far-right
Stance 4 -- The same DD, now far-left ... and another DD far-right

Posted by: PDP8E Oct 1 2021, 02:20 AM

.... Dust Devil Watches
SOL 210 21 images - 1 stance 4:15 PM -- NO DD
SOL 211 21 images - 1 stance 7:23 AM -- NO DD
SOL 212 no images
SOL 213 no images
SOL 214 15 images - 3 images - 5 stances 7:45 AM -- NO DD
SOL 214 21 images - 1 stance 8:40 AM -- NO DD


... more SOLS later...

Posted by: PDP8E Oct 1 2021, 09:03 PM

SOL 215 - Dust Devil Watch
21 Images -- 1 Stance -- 10:43 AM

A moving Dust Devil visible in all 21 frames
and a close-range GUST in front of the camera!

Posted by: PDP8E Oct 1 2021, 11:22 PM

SOL 215 B -- the 2nd DD sequence of that SOL ... and a strange one
30 Frames -- 1 stance -- 27 minutes long! -- 10:56 AM to 11:23 AM
The timing between frames is roughly: 33 sec -- 84 sec -- 33 sec -- 84 secs -- etc.

Gusts and Dust Devils!

EDIT: the 3rd DD sequenceof that Sol at 3:10 PM had no DDs

Posted by: djellison Oct 2 2021, 12:11 AM

There's one a bit like that on MSL.... take three frames - wait a minute - take three more. The three frames get you motion of any DDs in the scene - the minute wait the spreads them out to get more temporal coverage.

Posted by: PDP8E Oct 2 2021, 03:28 AM

This is the large DD that Damia B. pointed out when she made that amazing panorama!
(contrast-enhanced)

... and we are at conjunction for a few days

Posted by: PDP8E Oct 3 2021, 01:39 AM

Perseverance has been exposed to winds, gusts, and vortices for 200+ Sols
These 'containers' are associated with the mast stowage prior to landing ( i think ...)
Now they make excellent particle collectors... I hope to revisit them every few hundred Sols
GIF

Posted by: djellison Oct 3 2021, 02:35 AM

Yes - the RSM was stowed against these before being deployed - that's the left Navcam and MastcamZ cover you're looking at.

Posted by: PDP8E Oct 20 2021, 10:28 PM

SOL 236 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 1:45 PM local
DDs -- one in Stance 4 and another in 5

Posted by: PDP8E Oct 24 2021, 04:36 PM

SOL 241 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 11:00 AM local

DDs -- in Stance 4 and in 5

Posted by: PDP8E Oct 26 2021, 08:48 PM

SOL 242 - Dust Devil Watch
21 Images -- 1 Stance -- 1:00 PM
-- no DDs detected ---

Posted by: PDP8E Nov 1 2021, 09:09 PM

SOL 249 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 11:00 AM local

Only showing stance 1 -- others are quiet
Stance 1 has a minor DD on the far left - GIF is wiggled back and forth...

Posted by: PDP8E Nov 2 2021, 11:43 PM

SOL 250 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 11:50 AM local

Well-formed DD in Stance 4

Posted by: PDP8E Nov 5 2021, 08:49 PM

SOL 252 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 11:30 AM local

Another DD in Stance 4

Posted by: PDP8E Nov 8 2021, 01:31 AM

SOL 255 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 12:15 PM local

Only Stance 1 is shown -- a distant DD (or two) in the center
(the other Stances were very quiet) - a little wiggle back and forth too...

Posted by: PDP8E Nov 10 2021, 02:08 AM

SOL 256 - Dust Devil Watch
21 Images -- 1 Stance -- 1:50 PM

A DD marches across in all 21 images -- then another walks in from the left

Posted by: PDP8E Nov 10 2021, 08:58 PM

SOL 257 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 12:30 PM local

-- NO DDs

Posted by: PDP8E Nov 12 2021, 02:47 AM

SOL 258 - Dust Devil Watch
21 Images -- 1 Stance -- 11:45 AM

A wide and whispy DD in all images (low dust load? not enough contrast?)
-- then another appears to the right of Kodiak

Posted by: Bill Harris Nov 12 2021, 04:42 PM

May be a change in the nature of the vortex. Remember that the atmosphere is changing with the approach of Summer. The dynamics of the cyclonic thermal updrafts is bound to change. Dust devils are a visible manifestation of thermals with dust entrained.

Posted by: PDP8E Nov 15 2021, 03:56 AM

SOL 262 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 1:15 PM local

Stance 4 -- far off DD, center, climbing the crater rim

Posted by: PDP8E Nov 18 2021, 11:03 PM

SOL 263 - Dust Devil Watch
21 Images -- 1 Stance -- 1:30 PM

DD -- right of center - Distant and moving

Posted by: PDP8E Nov 22 2021, 12:28 AM

... a little catch-up...
Three posts coming... SOL 264, 265, 267

SOL 264 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 4:50 PM local ( very late in the day! )

Large DD in Stance 4 on the crater hill

Posted by: PDP8E Nov 22 2021, 12:31 AM

SOL 265 - Dust Devil Watch
21 Images -- 1 Stance -- 12:55 PM

Dual DDs -- right of center - Distant and moving -- one fizzles

edit -- I meant my other "right" (LEFT! of center)

Posted by: PDP8E Nov 22 2021, 12:34 AM

SOL 267- Dust Devil Watch
21 Images -- 1 Stance -- 11:25 AM

A nice DD on the march ( a comrade DD falters )

Posted by: PDP8E Nov 23 2021, 03:03 AM

SOL 269 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 4:06 PM local
NO DDs -- all quiet -- late in the day --

Posted by: PDP8E Nov 26 2021, 08:53 PM

SOL 271 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 1:10 PM local

Well-formed DD in Stance 4

Posted by: PDP8E Nov 29 2021, 03:36 AM

SOL 274 Dust Devil Watch
21 Images -- 1 Stance -- 12:45 PM

DD Conveyor Belt -- one marches off to the right -- another in the center -- and one pops up on the left

SOL 275 -- 3 images in 5 stances (15 images) -- 3:55PM -- No DDs

Posted by: PDP8E Dec 2 2021, 01:35 AM

SOL 278 Dust Devil Watch
21 Images -- 1 Stance -- 3:55 PM

Two DDs -- One is so easy to see -- can you see the other?

Posted by: PDP8E Dec 5 2021, 10:28 PM

... a little catch up ...

SOL 279 Dust Devil Watch
21 Images -- 1 Stance -- 4:20 PM -- NO DDs


SOL 280 Nav Cam (part of a LR pair) 1:32 PM
GIF

Posted by: PDP8E Dec 5 2021, 11:52 PM

SOL 280 Dust Devil Watch
360 degree quick peek (3 frames each in 5 stances) -- 2:38 PM local
DD in Stance 4 (center) and Stance 5 (right of Kodiac - faint)

Sol 281
21 images -- 1 stance - 3:05 PM -- NO DDs

Posted by: PDP8E Dec 8 2021, 11:09 PM

SOL 283 - 15 images (3x5 quick peek) -- 3:15 PM -- NO DDs, but there were clouds over Kodiak.

SOL 284 - 45 images ! -- 1 Stance - JPL Broke my simple-minded Detector
12:06 PM to 12:27 PM (21 minute session)
** 15 images = 496 x 1296 pixels
** 30 images = 256 x 656 pixels
** Interleaved...
** (I'll see what I can do later...)

But there was another DD watch at 12:30 -- 15 images -- 3x5 quick peek
There is a DD in Stance 3

Posted by: PDP8E Dec 9 2021, 03:12 AM

SOL 285 -- 21 images -- 1 Stance -- 11:42 AM
A DD seems to have come over the top of the Rover -- then we pick up the action.

4 DDs -- one on the crater wall --- the one that passed over the Rover -- a 'fire hose' DD off to the right
Near the end, a DD moves in from the left.

Posted by: PaulH51 Dec 9 2021, 09:01 AM

Great capture

We sure could do with one like that passing over InSight

Posted by: tau Dec 10 2021, 03:39 PM

Storyboard (corrected version) for the dust devils on sol 285.

Edit: The frames at second 17 and 21 were accidentally mixed up, which I didn't notice until I made an animation.
The storyboard is now corrected.

Posted by: PDP8E Dec 10 2021, 10:22 PM

SOL 286 -- 21 images -- 1 Stance -- 12:05 PM -- No DDs

Tau - I love that storyboard!

Posted by: tau Dec 11 2021, 11:23 AM

Animated dust devils from sol 285.
The interaction of the dust devil with the dunes and ripples in the first frame is interesting (see also http://www.unmannedspaceflight.com/index.php?act=attach&type=post&id=49881).

Posted by: TrappistPlanets Dec 11 2021, 05:19 PM

WOW! stunning

Posted by: PDP8E Dec 11 2021, 08:05 PM

SOL 287 -- DD Watch -- 15 Images -- 3 images in 5 Stances -- quick peek --- Noon
DDs in Stances 4 and 5:
Stance 4: minor DD in the center -- larger DD on right
Stance 5: pick up the progress of the larger DD from Stance 4

Posted by: PDP8E Dec 17 2021, 01:02 AM

SOL 291 -- 21 images -- 1 Stance -- 1:10 PM
We have 3 things going on ... a DD coming in from the left -- a gust passing the Rover -- and Clouds!

Posted by: PDP8E Dec 19 2021, 09:41 PM

NO DDs detected: SOL 292, 293, 294, 295, 296

Posted by: PDP8E Dec 22 2021, 02:00 AM

SOL 297 -- 21 images -- 1 stance -- 1:00PM
A well-formed and slow-moving DD in all frames

NOTE: Slow-moving DDs play havoc with the standard technique of averaging or median-ing all the frames to arrive at a 'normal background image' to analyze each individual frame against -- it causes the dark 'shadow' near the DD. -- I am starting to investigate another technique.

Posted by: PDP8E Dec 22 2021, 02:42 AM

SOL 298 -- 21 images -- 1 Stance -- 1:25 PM
A DD on the deltas

Posted by: PDP8E Dec 25 2021, 12:00 AM

HAPPY SOL 300 -- 21 images -- 1 Stance -- 11:10 AM
only Frame #1 has a DD before it 'evaporates' (if that's the word)
It is centered and on the deltas (far)
Here is the single frame:

Posted by: JRehling Dec 25 2021, 12:30 AM

The median is the special case of a given percentile rank per pixel, where that percentile happens to be 50. You might have better results with a different percentile, say, 25.

Posted by: PDP8E Dec 25 2021, 01:42 AM

SOL 300 DD Bonus
NAV Cam 11:45 AM

JRehling: That is a brilliant idea... I will give that a try

Posted by: PDP8E Dec 25 2021, 05:53 PM

SOL 301 -- 15 images -- 5 stances -- 1:40 PM
DD in stance 5
Here is just that sequence

Posted by: PDP8E Dec 26 2021, 07:45 PM

SOL 302 -- 21 images -- 1 Stance -- Noon
Distant DD, center, wait for it...

Posted by: tau Jan 5 2022, 10:17 AM

A "storyboard" an an animation of a dust devil on sol 308 during a Mastcam-Z multispectral photo series.
The Mastcam-Z filter number and the time in seconds after start of the series are annotated in the storyboard.
The difference-to-average method does not work here because of the spectral filters, therefore contrast enhancement was used.

Posted by: tau Jan 5 2022, 02:19 PM

The dust devil on sol 308 continues into the infrared region of the spectrum with Mastcam-Z right eye filters 1 to 5.
The Mastcam-Z filter number and the time in seconds after start of the series in the previous post are annotated.
Contrast enhancement did not work here. Instead the difference-to-average method with manual adjustments to each image was used.
Overexposed and/or clipped highlights (https://mars.nasa.gov/mars2020-raw-images/pub/ods/surface/sol/00308/ids/edr/browse/zcam/ZR1_0308_0694277926_943EBY_N0090000ZCAM03282_0340LMJ01.png to the first raw image) in the bright landscape around the dust devil resulted in featureless patches of medium gray, which are masked here with red color.
A second dust devil appears in this series.
Starting with filter ZR5, the dust devils merge with the bright infrared background.

Posted by: tau Jan 8 2022, 04:35 PM

Mastcam-Z images, an orthorectified HiRISE image, and a HiRISE digital terrain model were used to determine the route of the sol 308 dust devil on the ground.
Twenty control points of corresponding features were set in the Mastcam Z image and the HiRISE image.
With some measurements and calculations, pixel coordinates in the Mastcam-Z image could be transformed into map coordinates of the HiRISE image.
The length of the visible part of the dust devil's route is about 820 m.
The average horizontal ground speed was about 30 km/h, and even 36 km/h on average between second 0 and 57.
To verify the calculations, it would be interesting to see if the dust devil left a visible track.

Edit: corrected typo km/s to km/h (thanks to Floyd)

Posted by: Floyd Jan 8 2022, 05:38 PM

Was the horizontal ground speed actually m/s not km/s?

Posted by: Deimos Jan 8 2022, 05:50 PM

8.2 m/s, 30 km/hr.

Posted by: tau Jan 8 2022, 06:04 PM

It was a typo. Of course, supersonic dust devils are not possible.

820 m / 100 s = 8.2 m/s = 29.52 km/h (rounded value 30 km/h)

I can't wait for the day when I don't make typos.

Posted by: rlorenz Jan 9 2022, 09:45 PM

What is the diameter of the devil. Some years ago I identified an empirical law for the longevity of dust devils on Earth and Mars : Duration (s) = 40 * d^0.66 with d in m.

Apropos of this topic
Anyone interested in dust devils on Earth and Mars might enjoy my
Physics Today webinar to be held 2pm EST January 12, 2022 (I guess you
can view it online thereafter)
https://event.on24.com/wcc/r/3543264/A422D65AA31CDE2D0BBA18667191242C

Posted by: Bill Harris Jan 10 2022, 02:35 AM

I wondered about the possibility of transferring the DDs we see to a groundtrack on a map and seeing if a track was left.

--Bill

Posted by: tau Jan 10 2022, 10:09 AM

Here is a very rough estimate of the diameter of the dust devil using a scaled image.
The last three subimages where the dust devil begins to dissipate were not taken into account.
1 pixel corresponds to 0.76 m in nature.
Diameter of the brightes part where it touches the ground: 25 to 40 m
Diameter of the shadow: 60 to 70 m (local mean solar time was 11:09)
It was a nice coincidence that the dust devil entered the field of view exactly at the moment when the image series started.

Posted by: tau Jan 10 2022, 10:57 AM

Groundtracks on a map can be reconstructed only if we see in the photos the point where the dust devil touches the ground. In most cases this point is hidden behind local elevations.
For example, in http://www.unmannedspaceflight.com/index.php?act=attach&type=post&id=50074 a second dust devil emerges to the left from the existing one. However, its distance from the rover can be anywhere between 50 m behind the nearest ridge and 7000 m on the inner slope of the crater wall.

Posted by: tau Jan 10 2022, 02:18 PM

Control points are necessary to tie a photo taken by the rover to an orthorectified orbital photo.
Here are my 20 control points. Some small features are hidden by the crosses.
In this case, it was of great advantage that the dust devil passed a smooth slope with an incline towards the rover.

Posted by: PDP8E Mar 19 2022, 04:29 PM

Sol 372 DD watch
21 images - 11:40 AM

(I have a backlog of DDs -- broke my wrist -- sold my house - moved to a new one -- crashed PC -- but all set now....)

Posted by: Bill Harris Mar 20 2022, 06:12 AM

Be well!!
Looking forward to the Backlog.

--Bill

Posted by: tau Apr 10 2023, 04:23 PM

Sol 756 Navcam images of a dust devil ("storyboard" and animation).
The time interval between successive images was about 5 seconds.

Edit: The above images have been enhanced and colored to emphasize the dust devil.
The original images are black-and-white. Links to raw images: https://mars.nasa.gov/mars2020-raw-images/pub/ods/surface/sol/00756/ids/edr/browse/ncam/NLG_0756_0734060701_739ECM_N0372562NCAM00500_00_2I4J02.png, https://mars.nasa.gov/mars2020-raw-images/pub/ods/surface/sol/00756/ids/edr/browse/ncam/NLG_0756_0734060706_301ECM_N0372562NCAM00500_00_2I4J02.png, https://mars.nasa.gov/mars2020-raw-images/pub/ods/surface/sol/00756/ids/edr/browse/ncam/NLG_0756_0734060710_300ECM_N0372562NCAM00500_00_2I4J02.png

Posted by: PDP8E Jul 2 2023, 07:38 PM

Dust Devil on Sol 840
GIF -- Deep Histo