Guide to loading TFW files in ArcMap

Hi Everyone,

I found this guide while trying to figure out how to load my TFW file into ArcMap. Its a step-by-step guide to load your raster image and georeference it in ArcMap 9.x. Thought people might find it useful for homework or general use.

http://www.mcgill.ca/files/gic/georeference9.pdf

Cheers!

Method to Send *Large* Files Over E-Mail

I have found the following website:

http://www.mailbigfile.com/

It allows you to e-mail big files. This might be helpful when submitting homework.

Enjoy,

Adam

Free Image Viewer / Modification Tool

Just wanted everyone to know of the following tool that is very similar to Photoshop, but is absolutely free.

The GIMP 2:

http://www.gimp.org/

Click here, for the actual download location.

When downloading this do not forget to install GTK 2+ prior to installation... All of the instructions should be on the website.

WorldView I Launch Successful

On Tuesday, Sept. 18, WorldView I, the latest satellite imager from Digital Globe, was successfully launched from Vandenberg AFB. See video at

http://www.boeing.com/defense-space/space/bls/missions/worldview-1/

From the video, it will have 0.5m GSD (ground sample distance) and operate from a near circular orbit with approximate altitude of 500 km.

Producing PDFs on Windows for Free

If you need to produce a PDF for your homework, and are running Windows. There is a combination of two open source applications that will help. The main PDF generation is done by ghostscript, which has been ported from Linux to Windows. Make sure you install ghostscript first. The second program is PDFCreator, which creates a virtual printer. The virtual printer appears as a normal Window's printer. To produce a PDF, you just need to print your document as usual with PDFCreator as the target. The output from the printer is a PDF file, which you can then treat as any other PDF file.

I have tested with with MS Office, and it does produce a PDF file that the standard Adobe reader can handle.

MATLAB Cheat Sheet

For those new to MATLAB, I found a 12 page PDF cheat sheet of MATLAB commands at
http://www.math.umd.edu/~jeo/matlab_quickref.pdf.

Where are the solutions to the problems in the text?

Does anyone know where we can find the solutions to the problems listed at the end of each chapter in the "Introduction to Modern Photogrammetry" by Mikhail, Bethel & McGlone? I looked through the book, but didn't see any reference to where the solutions were, they didn't appear to be on the CD that came with the hard-cover book either. Is there a website somewhere with the solutions? Please blog me a response if you can help. Thanks,
Mike Flaherty

Session 2 summary mind map

I have taken my notes from the second session's presentation in a mind map format. If anyone would like to have a copy for their review, just drop me an email and I can send you PDF (36kb) version of it.

Just a a warning, these are just my notes, and so they may be incorrect and missing some information. You have been warned, and use them as your own risk.

Reduction of illumination

In today's lecture (session 2), professor mentioned three factors which reduce illumination on the edge of the image. At first, I'm a little confused because so many cosines (four, in total) are multiplied together for the illumination reduction and it's hard to figure it out only by verbal reasoning.
After thinking about it awhile, I tried to explain it using graphs. And this made me feel more comfortable. I hope it may also do help to other guys.
In figure 1, let's first assume that the light source is a sphere. Light emitted from the source is absorbed by the image film.

On the two different spheres, there are two differential area, S1 and S2. Because the distances from them to the light source are different and the irradiance (the incidence flux density, or flux per unit area) is inversely proportional to the distance, the irradiance at S2 is that at S1 multiplied by cos(phi) squared. So distance difference is the first factor contributing to illumination reduction.

But S2 indicated by red is not on the image film but it makes an angle phi with it. So the effective differential area on the film should be added a factor of cos(phi), as indicated by the orange area. Obliquity contributes also.

The above two factors are sufficient to explain illumination for a sphere light source. But in this course we are dealing with lens, which cannot be modeled as a sphere but roughly by a flat circular object like a coin. Figure 2 illustrates this factor.
After we changed the model of the light source, the light beam emitted from the source shrinks from the blue envelope to the yellow envelope. This is because the effective source is an ellipse indicated in orange. The shrink factor is cos(phi).

Combining all the three factors above, the total illumination reduction factor is four cos(phi) multiplied together.

TerraSAR X

TerraSAR X was successfully launched on June 15, 2007 and is producing good data. Produced and operated by the DLR (German NASA), the sensor will have a 16m scansar mode, a 3-6m strip map mode, and a 1-2m spotlight mode. Multi-polarization capability. I have heard rumors that there will be a tandem mission permitting 2-pass interferometry. Great news for everyone who needs data quickly and is tired of looking at clouds. http://www.dlr.de/tsx/start_en.htm