The following links are interactive calculators for reducing sights. Once you have clicked on the link, you can do "save as" in your browser to save the page. This allows you to use the calculators while you are disconnected from the web by accessing the saved page with your browser. This works because these pages are written in JavaScript which runs locally in your own browser and does not depend on a server.
Here is a paper on a simplified Sight Reduction Method and an online sight reduction calculator that can be used to check answers.
Here are the figures including the example and blank forms referenced in the text.
Figure 1 (postscript)
Figure 2 (text)
Figure 3 (text)
Figure 4 (text)
Figure 5 (text)
Tables for 36-47 degrees(text)
Here you can find the complete set of tables from 0 to 179 degrees in html format that you can print out and carry with you.
The following program can be used to generate either the text or html tables on the web site. It can be compiled with
cc abhav.c -lm -o abhavTo generate html tables, give
abhav -h table -s 0 -e 179and it will generate tables in files named table00.html to table59.html containing the tables starting from 0 degrees and ending at 179 degrees. Without the -h option, the output will be in text format and placed on the standard output. With netscape, the right mouse menu "save as" can be used to save a copy of the file. You will need to rename it to abhav.c before compiling.
This method is a simple yet accurate and with a copy of the modest length tables, can be easily performed without electronic equipment.
You can even try the online javascript sight reduction program above to check your answers.
Comments can be mailed to the Webmaster at: webmaster@snark.dhs.org
This is a javascript test link called jstest. It will likely give meaningless or wrong output. Don't use.