Looking for tide calculation algorithm

I'm looking to incorporate the calculation of high and low tides into my Delphi
software. For this I need algorithms telling me how to calculate the time of
high and low tides. Do you know where I can get such algorithms? I understand
it will probably involve complex calculations to find the position of the sun
and moon in relation to the earth and I am prepared for that.

I have searched the web and have not found any algorithms yet, just sites that
calculate tides for the oceans. I am making software to calculate the best
fishing times, which has something to do with the tides. So I would have to be
able to calculate the high and low tides for an INLAND location based on
latitude and longitude.


Thank you.


--
Freezone Freeware and Free Delphi Components
http://freezone.darksoft.co.nz http://chuckr.bravepages.com
http://www.bdsg.com/resources

"Chuck S." wrote in message
...
I'm looking to incorporate the calculation of high and low tides into my Delphi
software. For this I need algorithms telling me how to calculate the time of
high and low tides. Do you know where I can get such algorithms? I understand
it will probably involve complex calculations to find the position of the sun
and moon in relation to the earth and I am prepared for that.

That will be but the beginning of the ordeal. Much of the
physics of the tides is in the interaction of the water with
the geometry of the coastlines. For example, large bays
cause resonance effects. The Bay of Fundy comes to mind.

Greg Neill wrote:

"Chuck S." wrote in message
...
I'm looking to incorporate the calculation of high and low tides into my
Delphi software. For this I need algorithms telling me how to calculate the
time of high and low tides. Do you know where I can get such algorithms? I
understand it will probably involve complex calculations to find the
position of the sun and moon in relation to the earth and I am prepared for
that.

That will be but the beginning of the ordeal. Much of the
physics of the tides is in the interaction of the water with
the geometry of the coastlines. For example, large bays
cause resonance effects. The Bay of Fundy comes to mind.

I'm not looking to take bay action into account since I will be calculating
what I think are called "land tides". So does high tide for a land mass appear
as soon as the moon is overhead? Or is there a delay of x minutes? What would x
be?



--
Freezone Freeware and Free Delphi Components
http://freezone.darksoft.co.nz http://chuckr.bravepages.com
http://www.bdsg.com/resources

In article ,
Chuck S. wrote:
Greg Neill wrote:

"Chuck S." wrote in message
...
I'm looking to incorporate the calculation of high and low tides
into my Delphi software. For this I need algorithms telling me how
to calculate the time of high and low tides. Do you know where I
can get such algorithms? I understand it will probably involve
complex calculations to find the position of the sun and moon in
relation to the earth and I am prepared for that.

Computing the position of the Sun and the Moon isn't that complex if
you settle for a modest accuracy. On my web site (URL below) you'll
find what I believe to be among the simplest possible algorithms for
computing solar and lunar positions with an accuracy of one minute of
arc, and that ought to be enough for tidal computations.

That will be but the beginning of the ordeal. Much of the
physics of the tides is in the interaction of the water with
the geometry of the coastlines. For example, large bays
cause resonance effects. The Bay of Fundy comes to mind.

I'm not looking to take bay action into account since I will
be calculating what I think are called "land tides". So does high
tide for a land mass appear as soon as the moon is overhead? Or is
there a delay of x minutes? What would x be?

There's definitely a delay, but I don't know how long the delay is.

Tidal computations of the oceans and the seas depend a lot on
empirical data. I believe computations of land tides would need
to depend on empirical data too, but I suppose there are much
less land tide data available.

For what purposes do you want to compute the land tides?

--
----------------------------------------------------------------
Paul Schlyter, Grev Turegatan 40, SE-114 38 Stockholm, SWEDEN
e-mail: pausch at stockholm dot bostream dot se
WWW: http://www.stjarnhimlen.se/
http://home.tiscali.se/pausch/

On 10 Oct 2003 16:13:24 GMT, "Chuck S." wrote:

Greg Neill wrote:

"Chuck S." wrote in message
...
I'm looking to incorporate the calculation of high and low tides into my
Delphi software. For this I need algorithms telling me how to calculate the
time of high and low tides. Do you know where I can get such algorithms? I
understand it will probably involve complex calculations to find the
position of the sun and moon in relation to the earth and I am prepared for
that.

That will be but the beginning of the ordeal. Much of the
physics of the tides is in the interaction of the water with
the geometry of the coastlines. For example, large bays
cause resonance effects. The Bay of Fundy comes to mind.

I'm not looking to take bay action into account since I will be calculating
what I think are called "land tides". So does high tide for a land mass appear
as soon as the moon is overhead? Or is there a delay of x minutes? What would x
be?

Ocean tides are normally computed by fitting a trigonometric series to
observed tide height data. The periods (or frequencies) of the
trigonometric functions are related to apparent motions of the Sun and
Moon, but no one attempts to determine the state of the tide directly
from the positions of those bodies.

Land tides are so much smaller in magnitude that, so far as I know, no
one has attempted to predict them at all. Given the large local
variations in the properties of the Earth's crust, I would expect the
computation to be done in much the same manner as for Ocean tides,
fitting local observations to a series of periodic functions. Anything
else would be computationally awkward at best.

Al Moore

On 10 Oct 2003 16:13:24 GMT, "Chuck S." wrote:

Greg Neill wrote:

"Chuck S." wrote in message
...
I'm looking to incorporate the calculation of high and low tides into my
Delphi software. For this I need algorithms telling me how to calculate the
time of high and low tides. Do you know where I can get such algorithms? I
understand it will probably involve complex calculations to find the
position of the sun and moon in relation to the earth and I am prepared for
that.

That will be but the beginning of the ordeal. Much of the
physics of the tides is in the interaction of the water with
the geometry of the coastlines. For example, large bays
cause resonance effects. The Bay of Fundy comes to mind.

I'm not looking to take bay action into account since I will be calculating
what I think are called "land tides". So does high tide for a land mass appear
as soon as the moon is overhead? Or is there a delay of x minutes? What would x
be?
For water on Earth, the delay is about 4 hours because of friction and viscosity
of water. I do not know for land tides but i think the delay would be
shorter...

Good night!

Benoît Morrissette