<p>NASA has a land cover map that tells you what type of biome is on the Earth's surface:</p>
<p><a href="https://visibleearth.nasa.gov/images/61004/new-land-cover-classification-maps" rel="nofollow noreferrer">here</a></p>
<p>There are 17 different land types. If you download one of the two tiffs here and zoom into a couple of places you'll see that some pixels are black. This ends up being a value of 254, whereas all the other values are 0 to 16, for the 17 different values. But the black pixels you see there have the value of 254. Would you happen to know what these are? And where would I be able to find out?</p>

CC BY-SA 4.0
2023-09-29T10:26:19.877Z
I agree that it is very likely that this value means something like "no data" or "undefined".
hschoell
CC BY-SA 4.0
2023-09-29T17:44:39.537Z
given that the largest number possible in 8-bit hexadecimal is 255 it is almost certainly some type of coding error.
John
CC BY-SA 4.0
2023-09-30T05:32:13.647Z
@John Do you know where I can get a high detail land cover map like that in high res, a better one? I found this: https://lpdaac.usgs.gov/products/mcd12c1v061/ but the tiles don't even seem to be arranged in any comprehensible way.
Zebrafish
CC BY-SA 4.0
2023-09-30T17:37:27.050Z
no idea, sorry, I don't use nasa for much
John
<mapping><land-surface>
What does the value 254 mean on this map?
Zebrafish
# What does the value 254 mean on this map?

(Asked by: username_0 on 2023-09-29)

NASA has a land cover map that tells you what type of biome is on the Earth's surface:

[here](https://visibleearth.nasa.gov/images/61004/new-land-cover-classification-maps)

There are 17 different land types. If you download one of the two tiffs here and zoom into a couple of places you'll see that some pixels are black. This ends up being a value of 254, whereas all the other values are 0 to 16, for the 17 different values. But the black pixels you see there have the value of 254. Would you happen to know what these are? And where would I be able to find out?

**Tags:** mapping, land-surface

> **Comments:**
> **username_1**: I agree that it is very likely that this value means something like "no data" or "undefined".  
> **username_2**: given that the largest number possible in 8-bit hexadecimal is 255 it is almost certainly some type of coding error.  
> **username_0**: @username_2 Do you know where I can get a high detail land cover map like that in high res, a better one? I found this: https://lpdaac.usgs.gov/products/mcd12c1v061/ but the tiles don't even seem to be arranged in any comprehensible way.  
> **username_2**: no idea, sorry, I don't use nasa for much  

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## 0 answers

