Remote Sensing C

[cngu23]

Hm, my friend who did that test said it was from the Test Exchange. Looking at the history I cannot find any activity of it being removed. There are two questions that I cannot find the answer to. Could someone post the answer to these (not numbered the same as in the test itself)?

1. The best satellite for isolating chlorophyll absoption would be:
A Spot
B Landsat MSS
C GOES
D Landsat TM

2. A plane flying at 12,000 feet has two cameras, both cameras have the same focal length, one camera uses a 35 mm film size and the other uses a 240 mm film size. How would this affect the ground area recorded by the camera? A diagram would help. 2 pts

I believe the first one is Landsat TM

Not sure about the second one, but this may help http://cameras.about.com/od/commoncamer ... lained.htm

[JSGandora]

Thanks, is there a specific reason you chose Landsat MSS (assuming you meant MSS rather than TM)?

Additionally, would this just be a difference in area recorded? The 35 mm film size would record less ground area than the 240 mm film size? It should a little simple though.

[TheWrightBrother]

I'm a frosh and new to remote sensing. I was wondering what I should expect in terms of what atmospheric and hydrological features I need to identify, and what kinds of images and diagrams I should pepare to interpret.

[EastStroudsburg13]

The images can literally be anything on the Earth. Since it's Hydrosphere, it'll usually be of oceans, shorelines, clouds, lakes, rivers, estuaries, clouds, and other features. You should be able to identify each of these in images, as well as certain characteristics that they exhibit (e.g. capes and sandbars on shorelines, dams on rivers or reservoirs, etc.)

Being able to look at an image and interpret things from it is something that some people just grasp more easily than others, so the amount you need to practice really depends on you. If you had Road Scholar in B that should help, since you'll be familiar with what landforms look like from the sky. If not, you can see if you can get a few topo maps and study them, see what features they have. I never did this personally, but it just occurred to me that you could browse around on Google Maps set on satellite or Google Earth and find things that you are already familiar with so you can see what they look like from the sky.

For practice tests, you can check the 2013 Test Exchange Wiki and the Remote Sensing Wiki. Remote can be a very fun event once you get the hang of it. Hope that helped and I didn't overload you with information.

[meggers1221]

Okay i'm pretty new to remote sensing so this might sound like a bit of a dumb question, but i was doing a practice test and one of the questions was "In thermal images showing land and water in mid-latitudes during the fall, water is often seen as"
a. Light gray in the day and light gray at night
b. Light gray in the day and dark gray at night
c. Dark gray in the day and light gray at night
d. Dark gray in the day and dark gray at night

I've also seen previous questions asking me what the red in the image implied. does anyone know where i could find information on what colors imply in an image?

[EastStroudsburg13]

I'm leaning towards c, since water changes temperature more slowly than land. So during the day land will have a higher temperature than water, but at night the water will have a higher temperature than the land.

For your second question, I'm thinking red implies heat or warmth, since that's the general implication, but it depends on what purpose the image is serving. It can represent a lot of things, all anyone has to do is set a false color scheme and bam, you've got red.

[meggers1221]

Thanks, so to clarify colors themselves do not mean much, it depends a lot more on brightness?

[zyzzyva980]

If you're trying to identify what certain colors represent in an image (this is in regards to your second question) you first have to identify if the image is true-color or false-color. (This is usually fairly simple: Does the image look real?). If it's true color then it should be easy. If it's false color it's usually a bit trickier, but it's also simple once you understand the process used to make false-color images.

In a nutshell, the sensor collects energy at different wavelengths on the spectrum. Since some wavelengths (mostly IR) can't be seen by humans in true color, they can be assigned a color to appear in the picture (hence the term false-color, since it's not the actual color). There are a lot of reasons you might do this, but one of the more common ones is making infrared appear red. In this case, it's similar to what EAST said- this will often represent vegetation and brighter shades of red represent healthier plants.

You should also use context when interpreting images- take into account all information you've been given for the image. For a bit more on how to interpret images, look no further than here

[6nusher]

Are there any measuring tools that would be helpful to bring into competition that aren't mentioned in the rules? I think the triangle, ruler and protractor pretty much covers it all, but if anyone has any other items they would recommend, that would be helpful.

[FullMetalMaple]

The only measuring device I've ever had to use is a ruler. I believe you're also allowed a magnifying glass, which would probably be to your advantage to bring. You never know when you'll need it or anything else mentioned in the rules.