Fred Espenak's page says:
Important Note: The eclipse predictions in this interactive map DO NOT include the effects of mountains and valleys along the edge of the Moon. Such corrections for the lunar limb profile may change the contact times and eclipse durations by ~1-3 seconds.
Mainly because the google map version and guide8 agreed to less than a second with each other.
On 8/23/2017 5:33 PM, bob bob@bobsbits.net [guide-user] wrote:I just read the help about dynamical time (TD) and then delta-t and it says it uses a formula for future delta-t.
I did the quick info under help and it shows a delta-t of 68.7. which is very close to what you used below of 68.9.
On 8/23/2017 5:01 PM, bob bob@bobsbits.net [guide-user] wrote:How does guide compensate for leap seconds?
We do need to know the leap seconds elapsed to convert from T1 to UTC. Yes?
I have not updated guide in years(15 yrs?). So how do I input leap seconds in guide?
On 8/23/2017 4:07 PM, Luc Desamore luc_desamore@yahoo.ca [guide-user] wrote:It could have something to do with limb effect (real vs mean limb)
Luc
From occult 4.3.2.0 : (with limb effect)
S O L A R E C L I P S E P R E D I C T I O N for 2017 Aug 21
East Longitude - 88 6.00
Latitude 37 4.10
Altitude 0 m.
TT-UTC 69.2 secs Prediction basis: DE430
UT1-UTC 0.2 secs ▲T [= TT-UT1] 68.9 secs
Event UTC P.A. alt. Differential Corrections
h m s o o A B C
First Contact 16 55 6 293 61 2.10 -0.59 -0.03
Baily beads @2nd 18 23 1
Second Contact 18 23 9.5 120.9
Maximum Eclipse 18 24 30 64 2.06 -1.25 -0.01
Third Contact 18 25 49.3 293.4
Baily beads @3rd 18 25 56
Last Contact 19 50 23 114 54 1.62 -1.68 0.01
[2nd and 3rd contacts are based on the lunar limb derived from LRO LOLA]
Magnitude at Maximum Eclipse 1.013
Magnitude (diameter ratio) 1.031
_______________________________________________________________________________
without limb effect :S O L A R E C L I P S E P R E D I C T I O N for 2017 Aug 21
East Longitude - 88 6.00
Latitude 37 4.10
Altitude 0 m.
TT-UTC 69.2 secs Prediction basis: DE430
UT1-UTC 0.2 secs ▲T [= TT-UT1] 68.9 secs
Event UTC P.A. alt. Differential Corrections
h m s o o A B C
First Contact 16 55 6 293 61 2.10 -0.59 -0.03
Second Contact 18 23 11 122
Maximum Eclipse 18 24 30 64 2.06 -1.25 -0.01
Third Contact 18 25 50 286
Last Contact 19 50 23 114 54 1.62 -1.68 0.01
Magnitude at Maximum Eclipse 1.013
Magnitude (diameter ratio) 1.031
On 2017-08-23 20:40, bob davis bob@bobsbits.net [guide-user] wrote:So I am chasing down an anomaly of the timing...
I was at
37.06769 -88.10091
which is down to a 1.112 meter
Nasa google maps showed totality begging at.
and guide8.0 showed the following:
I timed it at:
13:23:08
I wonder if it has something to do with leap seconds?
-- Bob Davis 9 Meadow Lane Exeter NH 03833 603-778-0781-- bob davis 9 Meadow Lane Exeter NH 03833 603-778-0781-- bob davis 9 Meadow Lane Exeter NH 03833 603-778-0781-- bob davis 9 Meadow Lane Exeter NH 03833 603-778-0781