# Drift Star Method

### #1

Posted 19 October 2010 - 01:22 AM

I just added a another page that contain the "Drift Star Method" to determine the AFOV.

I am providing the direct link where you can test your equipment and in return post your result here in this post or PM me the difference Data obtain when compare to your past test conducted. This way It will facilitate me to see if there is any problem in calculation.

Your help will appriciated. Here is the LINK

### #2

Posted 03 November 2010 - 08:49 AM

### #3

Posted 01 January 2011 - 01:47 AM

### #4

Posted 13 January 2011 - 12:24 PM

### #5

Posted 15 January 2011 - 10:53 PM

Did you check

**with declination**or

**simple method**?

### #6

Posted 16 January 2011 - 03:58 PM

### #7

Posted 18 January 2011 - 01:58 PM

I did with declination. Actually, the results I got surprised me, so when I say "working fine", I mean the page loads and all the functions seem operational. I haven't had time to double check the actual math, so for now I'm only hoping it's correct!

I checked some of my eyepieces collection but I used the "Simple" method and it look like the formula is working OK. Here is the formula:

***********************************************************

'*************** FORMULA ***************

' Convert into seconds by multiply 24 Hours with 60 Minutes then Multiply 60 seconds to get the total seconds which is 86400

' Divide the 86400 seconds with 360 degrees to get ARC SECONDS.

' The result is 240 then mean drifting time of a star divide by 240 to get the result.

' OR

' Divide 360 with 86400 to get 0.00417 which then be multiplied with the mean drifting time of a star to get the same result.

'HERE IS THE FORMULA AS BELOW:

'TFOV=TIME/240

' OR

'TFOV=TIME*0.00417

TFOV=ElaspedTime/240

### #8

Posted 18 January 2011 - 09:14 PM

### #9

Posted 18 January 2011 - 11:55 PM

I believe that's the formula for a drift test at the celestial equator. For a star of higher or lower declination, you need to include a sine or cosine factor, I don't remember which.

**'FORMULA ======>> (Field of view=Drift Time x Cos(Star's Declination) x360 / 86164 seconds**

'TFOV= ElaspedTime x (Cos(Declination)x360) /86164

TFOV=Cos(Declination)

TFOV=TFOV*360

TFOV=TFOV*ElaspedTime

TFOV=(TFOV/86164)

'TFOV= ElaspedTime x (Cos(Declination)x360) /86164

TFOV=Cos(Declination)

TFOV=TFOV*360

TFOV=TFOV*ElaspedTime

TFOV=(TFOV/86164)

I took teh formula from "WIKI" but it is with the known declination which I called it "TFOV with declination"

About accuracy, I am not 100% sure but you or some one will acknowledge me.

Thank you,

### #10

Posted 01 March 2011 - 11:00 PM

Just add "video option" in Reviews and Articls section. Now, anyone can include links, Video, Pictures or mix mode in both reviews and articls. If you do then please, keep the file up to 4GB.

Thank you,

### #11

Posted 10 April 2012 - 02:36 PM

No need to login in certain area anymore. Now, you can read or upload anything you want. I have made stronger security so I do not need to use "LogIn mode" anymore.

Thank you,

### #12

Posted 20 April 2013 - 08:18 PM