Hurricane Harvey - Cloud base and large areas of flooding


Hi folks,

Want to welcome the newer folks and answer these questions about size/space.

Tomnod knows (because of the 2 years of crowdsourcing) that a thick cloud base is very frustrating to Nodders. We can’t see! But neither can the satellites-- yet. DG has been training the server to recognize shapes. In fact, that is PART of what Nodders do as we mark what we do see— we teach the server how to recognize shapes. For example, when we see a damaged corner of a house but the rest is obscured by clouds, that one little tag on a corner piece can help teach shapes for further campaigns years from now.

As to why we don’t mark cloud tiles, it is not really needed. All non-tags say is “We cannot SEE anything”, not “nothing here”. Data analysis goes on at DigitalGlobe. They can easily see “Houston… we got clouds” (not as dramatic as the line from Twister, “We got cows”… but Tn does see it.) So you don’t need to worry about clouds.

ALSO, this was “first best imagery” after a #4 hurricane that was still a tropical storm east of Houston. DG will often (not always) run another pass over a storm area once the cloud bank shifts or clears out. If they do, great, we can do more tagging. But they don’t need to… they can work their magic with numbers… X number of tags per Xx area means XXxX houses affected. They can even use numbers to estimate human population per house x Xx area.

The other concern is large swaths of flooding. Again, long-time Nodders understand; it used to frustrate us, too. (I think it was England where nearly every street was affected.) But rather than having us mark water, Tn needs us to focus on homes/buildings (last I heard it was est at over 100,000), roads & bridges, and garbage. Tn NEEDS the individual building counts. Oh my, I remember doing Canada’s fire where we marked house after house. Or when we did the earthquake overseas. Oh my.

For roads, mark the beginning… then, I mark at main points or turns. On long stretches, like highways, you can mark one tag every inch or two to show continuous water over a highway or road. I saw one that (I think Claus posted)-- just 3 tags marking the beginning of water on a highway-- that was marked well, showing that every lane was blocked.

I have not seen any yet, but I’d use the garbage pile tag on vehicles blocking or sitting in roadways or parking lots where it was clearly underwater. Remember, vehicles were in driveways underwater. And of course, piles of trash. Ugh.

Remember, folks in Texas already know the big scene… the “miles and miles” of water that we see here. But they need the small detail work-- that’s what we do. Every tag we place on single items helps ground-authorities “see” better what lies ahead and beyond. Our detailed work matters.


Here’s a trash heap I found on dry land.
Tomnod_Hurricane Harvey_Houston TX_trash heap


I found lots of places that looked the same but were just Texas rock piles and whatnot.


I understand the need to determine the extent of the flooding to houses but when you get a whole large estate under water there are hundreds of houses to click, Please set up a way to draw a box around them.


On tagging campaigns, we cannot do Draw… and vice versa.


Understand your point about zero tags in a tile means the user cannot see anything, but thats not necessarily always the case. There are large swathes of these maps which are agricultural land and don’t contain any buildings. By applying the 0 tag method, these areas would also be deemed as requiring rescan, when actually there is nothing to tag. A method of tagging a tile as cloud covered would prevent this. Similarly a tag for “this tile is empty / doesn’t need tagging” could further assist.
If the cloud covered tag was “a thing” then I think the guidance should be that it should only be applied once the tile has been compared against the old imagery, and that shows buildings are present, and are therefore in an undetermined state. This prevents the workload resource of those when the next satellite scan presents a clear tile, efforts can be re-routed to these areas as the ‘priority’.

On an unrelated note, I’ve noticed that the tag type actually doesn’t seem to make a difference. I’ve accidentally applied the wrong tag a few times (see my previous comments about being able to switch tags using hot keys), but its still telling me that “x others agree” that the building I’ve just tagged is a flooded road… Not sure if this would normally happen (this is only my second campaign, first being MH370 a few years ago), or if it is supposed to just show how many others tagged the same point. Also, when I did this in the early part of this campaign (when I was below 1k consensus score), I noticed that if you deleted your tag and added it again, the consensus increases by the same amount again, instead of reducing upon deletion of the tag. Again, not sure if this is by design, but doesn’t seem right to me.

Hurricane Harvey - Jump to Priority Area Not Working

Now I like that idea; that would be useful :grin:


Usually they do update the maps as and when they can get a clearer image Oli :slight_smile:


We already have similar to that for the “Seal or No Seal” campaign… 1 for “Seal” (not used very often!) and 2 for “No Seal”. So surely it shouldn’t be TOO difficult to program into the interface…


I just accidentally tagged a trash heap as a damaged building, there were no others in agreement. When I switched it to tag trash heap, there was one other in agreement! Maybe others have made the same mistake without realising this and so not corrected their mistake as you have; I suppose that’s one explanation for it :confused:


I had inadvertently tagged 3 flooded houses as flooded roads. I went back and changed the tags while watching my counter at the top right corner. As I deleted the tags, my counters dropped. When I tagged them correctly as flooded houses, both counters went up again. Seems to work okay for me. :thinking:


Hi Helen,

The Seal-No Seal is a Poly Campaign. I’ve never seen the 1, 2 (like a Poly campaign) mixed into a Tagging campaign.


That so true. A poly campaign is a simple “Yes” or “No” question where the 1 and 2 corresponds to the yes and no. Tagging campaigns can have zero, a few or many tags - and different tags at that - per map tile. Trying to add numbers into the equation would be a programmer’s nightmare. :upside_down_face:


The 1,2,3,4 Oli, Helen and I are thinking are switches for the various tags. The Q and W are switches, to switch between maps, so to switch tags by numbers should be just as simple.
1 = Blocked Bridge,
2 = Flooded/Damaged Building,
3 = Flooded/Blocked Road,
4 = Trash Heap

I’ve assigned numbers to run little macros I’ve created in the past, so I would have thought it was relatively simple to do this for switching between the various tags. That’s your basic coding stuff which should be childs play to a programmer I would have thought :wink:


That’s true, can’t say I’ve ever seen it either. My thinking is that the interfaces are superficially similar (they display in the same way on screen) - even with my very limited programming knowledge, I’d have thought it would be possible to customise the interface for a tagging campaign to allow tag selection by keyboard input. Q/W toggle has already been achieved…!
Anyway, it could be one for the superb techie-types at Tomnod to consider for future improvements…


I’ve seen tagging campaigns where we’ve had more than 2 choices, and they’ve all had numbers assigned.

Placing the tags in the images would probably be a programmers nightmare, but just toggling between them would be much easier on the mouse hand, less distance to travel to change.


Hi all, thanks for all your excellent work on the campaign! And thanks for all the good advice floating around this thread.

I just want to mention that tag type may not seem to matter as you’re clicking along, when we at DG wrap up the campaign and put the final data sets together it does matter. We often need to go in and manually remove incorrect tag types, which is often a prohibitively large job. So the “cleaner” you can make your data in the first pass, the better the data will be in its final form for the people who would like to use it! Thanks all.


Hadn’t realised how much of a discussion I’d triggered with that suggestion, haha. As a reasonably experienced programmer, I wouldn’t have thought it would be a massive amount of effort to incorporate, especially considering q/w are already in use. But then I equally know that the second you underestimate these things, they tend to become biblically challenging, lol.

But as Mel_Nod says, the cleaner the data, the easier DG’s role is with ‘cleansing’ the data at the end. IMO, having the ability to change tags in this way would be an effective way of achieving this.

My brain works in a very visual way, which is how I’ve noticed the wrong tag straight away as its not the colour I was expecting, and because most of my tags thus far have been for buildings, not roads, so the second I tag a house in blue, alarm bells ring and I correct it. So I’d like to say my tags should generally be as I intended… Famous last words though, eh?