Re: Looking for minutes and seconds correction for whole year for Equation of Time plaque

[Kevin Karney]

Hi Ken
I you want to observe how the Equation of Time varies over the years, go to my 
website
http://www.precisedirections.co.uk/Sundials/index.html

The second item may be of interest to you. It gives a table of EoTs (including 
the longitude correction for your time zone). And you can choose either a 
single year or a four year cycle.
For the four-year cycle, the average local noon EoT is calculated for each 
calendar date, except 29 Feb, which stands on its own. If you want the EoT 
without the longitude correction, set your longitude to your time zone 
longitude.

The calculations used are far more rigorous than needed for gnomonic purposes. 
They use the complete VSOP theory as described by Meeus and the EoT is 
topographical rather than geocentric (which only makes a marginal difference). 
If you use browser (like Chrome) which allows you to see the web-page source, 
you can see the calculations involved. (In Chrome, select View>Developer>View 
Source)
EoTs calculated have an accuracy of +/- .06 secs of time - using US Naval 
Observatory's MICA program as standard.
I think it is interesting to see how the 4-year table changes as one jumps 4 
years into the future...  

See the first item on the original page for comments on the calculations
and consider using a "Victorian EOT" table which gives all the information 
needed but in a tenth of the space

The Latitude/Longitude finder - using Google Earth is a bit ratty, but seems to 
work for Elizabethtown.

Let me know if you have any problems.

Best wishes
Kevin


> On 26 Jan 2017, at 00:21, Kenneth R clark  wrote:
> 
> I had an error message from AOL Sorry for no subject line and my files were 
> not sent.
> Let me retry with this account.
> 
> Hi everyone,
> 
>  I am working on my Equation of Time plaque for my aluminum cross 
> sundial.  All the instructions and graphics and EQT will be on an 8 ½” 
> diameter ½” aluminum plate.  I do not want to use the standard graph found on 
> many sundials but instead a chart for the whole year, mins and secs, to add 
> or subtract total correction to get watch time.  I do not have much room for 
> detailed instructions.
> 
>  I looked at difference sources for the chart and would like to verify 
> the most accurate times to use the four year leap year cycle for a church at 
> 40.1526N, 76.6038W.   I have looked at the Solar Noon calculator, Sonne and 
> Shadows-(cannot input decimal degrees?)  Are there other sources or 
> spreadsheet programs?
> 
>  I like to convey that sundials are accurate.  I envision that a person 
> will wait till the shadow is on a line and the person will know what time it 
> is suppose to be even though this type of sundial may not be design for 
> precision.
> 
>  I made a quick drawing.  There will be some type of sun image at the top 
> and a logo at the bottom for the location.  The chart in the center is from 
> another project that I did just to see how it would look and if the printing 
> is large enough to read.  I would have to change the inputs to standard time 
> for the whole year.  I have also attached a picture of the sundial.
> 
>  I just want to know if I am using the right times and would appreciate 
> any comments or suggestions.
> 
> Thanks very much
> 
> Ken Clark 
>   
> 
> Elizabethtown, PA
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial 
> 
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

RE: Looking for minutes and seconds correction for whole year, for Equation of Time plaque

[Robert Kellogg]

I have used Pyephem (a Python programming module) for accurate 
computation of solar transit and have put it to service to compute EOT 
for Ken's latitude and longitude.  However, doing it to the second is 
pure fiction as the tropical year does not precisely repeat after 4 
years cycle ... and any one year in the 4 year cycle is off even more.


Bob


---
https://lists.uni-koeln.de/mailman/listinfo/sundial

RE: Looking for minutes and seconds correction for whole year for Equation of Time plaque

[Dave Bell]

Thanks for reminding us of your work, Kevin!

That’s a lovely piece of JavaScrpt!

 

Dave

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Kevin Karney
Sent: Friday, January 27, 2017 2:40 AM
To: Kenneth R clark 
Cc: sundial@uni-koeln.de
Subject: Re: Looking for minutes and seconds correction for whole year for 
Equation of Time plaque

 

Hi Ken

I you want to observe how the Equation of Time varies over the years, go to my 
website

http://www.precisedirections.co.uk/Sundials/index.html

 

The second item may be of interest to you. It gives a table of EoTs (including 
the longitude correction for your time zone). And you can choose either a 
single year or a four year cycle.

For the four-year cycle, the average local noon EoT is calculated for each 
calendar date, except 29 Feb, which stands on its own. If you want the EoT 
without the longitude correction, set your longitude to your time zone 
longitude.

 

The calculations used are far more rigorous than needed for gnomonic purposes. 
They use the complete VSOP theory as described by Meeus and the EoT is 
topographical rather than geocentric (which only makes a marginal difference). 

If you use browser (like Chrome) which allows you to see the web-page source, 
you can see the calculations involved. (In Chrome, select View>Developer>View 
Source)

EoTs calculated have an accuracy of +/- .06 secs of time - using US Naval 
Observatory's MICA program as standard.

I think it is interesting to see how the 4-year table changes as one jumps 4 
years into the future...  

 

See the first item on the original page for comments on the calculations

and consider using a "Victorian EOT" table which gives all the information 
needed but in a tenth of the space

 

The Latitude/Longitude finder - using Google Earth is a bit ratty, but seems to 
work for Elizabethtown.

 

Let me know if you have any problems.

 

Best wishes

Kevin

 

 

On 26 Jan 2017, at 00:21, Kenneth R clark  > wrote:

 

I had an error message from AOL Sorry for no subject line and my files were not 
sent.

Let me retry with this account.

 

Hi everyone,

 

 I am working on my Equation of Time plaque for my aluminum cross sundial.  
All the instructions and graphics and EQT will be on an 8 ½” diameter ½” 
aluminum plate.  I do not want to use the standard graph found on many sundials 
but instead a chart for the whole year, mins and secs, to add or subtract total 
correction to get watch time.  I do not have much room for detailed 
instructions.

 

 I looked at difference sources for the chart and would like to verify the 
most accurate times to use the four year leap year cycle for a church at 
40.1526N, 76.6038W.   I have looked at the Solar Noon calculator, Sonne and 
Shadows-(cannot input decimal degrees?)  Are there other sources or spreadsheet 
programs?

 

 I like to convey that sundials are accurate.  I envision that a person 
will wait till the shadow is on a line and the person will know what time it is 
suppose to be even though this type of sundial may not be design for precision.

 

 I made a quick drawing.  There will be some type of sun image at the top 
and a logo at the bottom for the location.  The chart in the center is from 
another project that I did just to see how it would look and if the printing is 
large enough to read.  I would have to change the inputs to standard time for 
the whole year.  I have also attached a picture of the sundial.

 

 I just want to know if I am using the right times and would appreciate any 
comments or suggestions.

 

Thanks very much

 

Ken Clark   

Elizabethtown, 
PA

---
  
https://lists.uni-koeln.de/mailman/listinfo/sundial

 

---
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Re: Looking for minutes and seconds correction for whole year for Equation of Time plaque

[Thibaud Taudin Chabot]

Some time ago when I was able to use the 
mainframe computer of my employer I made a list 
of declination and time equation for each day for 
the years 2000-2099 and calculated the mean 
values for each date. I found the list again and 
attach it for who is interested.

Thibaud


Hi everyone,


 I am working on my Equation of Time plaque 
for my aluminum cross sundial.  All the 
instructions and graphics and EQT will be on an 
8 ½” diameter ½” aluminum plate.  I do not want 
to use the standard graph found on many 
sundials but instead a chart for the whole 
year, mins and secs, to add or subtract total 
correction to get watch time.  I do not have 
much room for detailed instructions.



 I looked at difference sources for the 
chart and would like to verify the most 
accurate times to use the four year leap year 
cycle for a church at 40.1526N, 76.6038W.   I 
have looked at the Solar Noon calculator, Sonne 
and Shadows-(cannot input decimal 
degrees?)  Are there other sources or spreadsheet programs?



 I like to convey that sundials are 
accurate.  I envision that a person will wait 
till the shadow is on a line and the person 
will know what time it is suppose to be even 
though this type of sundial may not be design for precision.



 I made a quick drawing.  There will be 
some type of sun image at the top and a logo at 
the bottom for the location.  The chart in the 
center is from another project that I did just 
to see how it would look and if the printing is 
large enough to read.  I would have to change 
the inputs to standard time for the whole 
year.  I have also attached a picture of the sundial.



 I just want to know if I am using the 
right times and would appreciate any comments or suggestions.



Thanks very much


Ken 
Clark 
Elizabethtown, PA



https://lists.uni-koeln.de/mailman/listinfo/sundial
---
https://lists.uni-koeln.de/mailman/listinfo/sundial



--
Th. Taudin Chabot, . tcha...@dds.nl



Mean values declination sun and time equation at 12:00 GMT
calculated over the years 2000 - 2099
==
   Day   - Declination sun    -- time equation ---
DatenrDD:MM:SS.ssDD.ddSSS.ssH:MM:SS.ssH.hh
--
01JAN   1-22:58:00.38   -22.966771   -211.953356   -0:03:31.95   -0.058876
02JAN   2-22:52:40.95   -22.878043   -239.917845   -0:03:59.92   -0.066644
03JAN   3-22:46:54.21   -22.781725   -267.534094   -0:04:27.53   -0.074315
04JAN   4-22:40:40.32   -22.677866   -294.772817   -0:04:54.77   -0.081881
05JAN   5-22:33:59.46   -22.566516   -321.605383   -0:05:21.61   -0.089335
06JAN   6-22:26:51.82   -22.447729   -348.003856   -0:05:48.00   -0.096668
07JAN   7-22:19:17.63   -22.321563   -373.941044   -0:06:13.94   -0.103873
08JAN   8-22:11:17.09   -22.188079   -399.390535   -0:06:39.39   -0.110942
09JAN   9-22:02:50.43   -22.047343   -424.326734   -0:07:04.33   -0.117869
10JAN   10   -21:53:57.92   -21.899421   -448.724903   -0:07:28.72   -0.124646
11JAN   11   -21:44:39.79   -21.744385   -472.561195   -0:07:52.56   -0.131267
12JAN   12   -21:34:56.31   -21.582309   -495.812681   -0:08:15.81   -0.137726
13JAN   13   -21:24:47.77   -21.413269   -518.457388   -0:08:38.46   -0.144016
14JAN   14   -21:14:14.45   -21.237347   -540.474318   -0:09:00.47   -0.150132
15JAN   15   -21:03:16.64   -21.054623   -561.843480   -0:09:21.84   -0.156068
16JAN   16   -20:51:54.66   -20.865184   -582.545908   -0:09:42.55   -0.161818
17JAN   17   -20:40:08.82   -20.669116   -602.563685   -0:10:02.56   -0.167379
18JAN   18   -20:27:59.44   -20.466511   -621.879958   -0:10:21.88   -0.172744
19JAN   19   -20:15:26.85   -20.257459   -640.478956   -0:10:40.48   -0.177911
20JAN   20   -20:02:31.40   -20.042056   -658.346003   -0:10:58.35   -0.182874
21JAN   21   -19:49:13.43   -19.820398   -675.467526   -0:11:15.47   -0.187630
22JAN   22   -19:35:33.30   -19.592582   -691.831067   -0:11:31.83   -0.192175
23JAN   23   -19:21:31.36   -19.358710   -707.425286   -0:11:47.43   -0.196507
24JAN   24   -19:07:07.98   -19.118883   -722.239967   -0:12:02.24   -0.200622
25JAN   25   -18:52:23.54   -18.873204   -736.266017   -0:12:16.27   -0.204518
26JAN   26   -18:37:18.40   -18.621779   -749.495468   -0:12:29.50   -0.208193
27JAN   27   -18:21:52.97   -18.364713   -761.921470   -0:12:41.92   -0.211645
28JAN   28   -18:06:07.61   -18.102114   -773.538288   -0:12:53.54   -0.214872
29JAN   29   -17:50:02.72   -17.834090   -784.341294   -0:13:04.34   -0.217873
30JAN   30   -17:33:38.71   -17.560752   -794.326959   -0:13:14.33   -0.220646
31JAN   31   -17:16:55.95   -17.282209   -803.492836   -0:13:23.49   -0.223192
01FEB   32   -16:59:54.87   -16.998574   -811.837555   

[no subject]

[clarkkr--- via sundial]

Diese Nachricht wurde eingewickelt um DMARC-kompatibel zu sein. Die
eigentliche Nachricht steht dadurch in einem Anhang.

This message was wrapped to be DMARC compliant. The actual message
text is therefore in an attachment.--- Begin Message ---

 Thanks Bob and everyone else for their input.  The EQT really does change 
way into thefuture. 


  I am leaning towards Kevin Karneywebsite:  
http://www.precisedirections.co.uk/Sundials/index.htmlusing a “Victorian EOT” 
table adding or subtracting minutes.  I could set it into the future 2050 and 
afterthat I am sure I will not be around or if the sundial is still standing.


Thanks,


Ken Clark   

  
Elizabethtown,PA



-Original Message-
From: Robert Kellogg 
To: sundial 
Sent: Fri, Jan 27, 2017 10:40 am
Subject: RE: Looking for minutes and seconds correction for whole year, for 
Equation of Time plaque

I have used Pyephem (a Python programming module) for accurate 
computation of solar transit and have put it to service to compute EOT 
for Ken's latitude and longitude.  However, doing it to the second is 
pure fiction as the tropical year does not precisely repeat after 4 
years cycle ... and any one year in the 4 year cycle is off even more.

Bob


---
https://lists.uni-koeln.de/mailman/listinfo/sundial


--- End Message ---
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Looking for minutes and seconds correction for whole year, for Equation of Time plaque

[Kenneth R clark]

 Thanks Bob and everyone else for their input.  The EQT really does change 
way into the future.
 
  I am leaning towards Kevin Karney website:  
http://www.precisedirections.co.uk/Sundials/index.html using a “Victorian EOT” 
table adding or subtracting minutes.  I could set it into the future 2050 and 
after that I am sure I will not be around or if the sundial is still standing.

Thanks,

Ken Clark   

Elizabethtown, PA
I tried sending this message by AOL account.  Just not working!


- Original Message -
From: "Robert Kellogg" 
To: sundial@uni-koeln.de
Sent: Friday, January 27, 2017 10:39:39 AM
Subject: RE: Looking for minutes and seconds correction for whole year, for 
Equation of Time plaque

I have used Pyephem (a Python programming module) for accurate 
computation of solar transit and have put it to service to compute EOT 
for Ken's latitude and longitude.  However, doing it to the second is 
pure fiction as the tropical year does not precisely repeat after 4 
years cycle ... and any one year in the 4 year cycle is off even more.

Bob


---
https://lists.uni-koeln.de/mailman/listinfo/sundial

---
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