Any GIS analysts or experts in remote sensing at DU?

[Swamp Rat]

Just wondering, as I have questions regarding EM spectra of earth objects.



MODS: I cross-posted this in the Skepticism, Science and Pseudoscience Group, though I have never encountered GIS scientists in that forum in the past. Please allow this thread to remain in GD for a few hours in order to get as many responses as possible. :)

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=247&topic_id=12502&mesg_id=12502

[annabanana]

1. What is "GIS"?

(Sounds interesting)

[Swamp Rat]

2. Geographic Information Science

- and/or - Geographic Information Systems

I use computers to do spatial analysis, and to create maps based on various types of statistical data, as well as vector (LIDAR for elevation) and raster (digital otho - satellite imagery) graphics. At the moment I am studying spectral properties of earth objects such as water, soil, and vegetation. I posted this thread because I plotted a graph (similar to the OP) of a few objects based on spectra, and I found what may be an anomaly for a dark object (dark matter absorbs EM). I just wanted a second opinion before I get my alloted one hour of sleep. :boring:

edit: EM = electromagnetic energy

[hootinholler]

4. I've been doing GIS lately....

But, working on a spatially enabled web site, I'm not that conversant in EM spectral analysis, although I did work on magnetic and gravimetric surveys in the past. Perhaps some HAMS could help? Those guys now the EM spectrum and natural causes for variations pretty well.

What's the anomaly?

Bon jour, mon ami.

-Hoot

[Swamp Rat]

5. Way'at hootinholler!

Bon jour, cher! :hi:

Oh, it's a very small bit of reflectance on a dark object in the short wavelength @ approximately 430.6 nm. Nothing else shows up as all the EM was absorbed. The sample was a LANDSAT 4 in the visual range and NIR. I could tell more if I could see TIR band.

I'm somewhat of a novice in this area too, but I'm pretty sure the HAMs like to deal in longer waves like microwaves. :D

I am about to get my GIS certification, and most of my work has focused on mapping urban resources in New Orleans and other U.S. cities, but I am now training in remote sensing.

[hootinholler]

6. How big an area?

Could it have been a sensor glitch? Does it appear on multiple passes? Are the edges sharp?

Hmmm, a visible and NIR sink? Interesting and if harnessable a quite useful thing if one wanted to keep something in the dark so to speak.

Possibly still worth talking to a HAM though, there are harmonic interactions after all, even down from XRay wavelengths.

Edit to ask if you have a geometry for it? Which is what I meant by sharp edges. Have you plotted it? what's nearby?

-Hoot

[Tesha]

3. So what's your anomalous question? (NT)