From: Douglas Yazell Message-Id: Content-Type: multipart/alternative; boundary="Apple-Mail=_0E3859C5-85EF-45DA-87F4-EB2DCF5B07A1" Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3696.120.41.1.3\)) Date: Fri, 11 Aug 2023 18:09:55 -0500 Subject: Re: Testing A Supplemental Earth Orientation Model Bcc: Douglas Yazell In-Reply-To: <4EB7CADB-AE3E-40D7-815D-4807460A1021@earthlink.net> To: Daniel Adamo References: <4EB7CADB-AE3E-40D7-815D-4807460A1021@earthlink.net> X-Universally-Unique-Identifier: 8650C1A9-E206-4E34-AC2E-3A92FB9F9DF1 --Apple-Mail=_0E3859C5-85EF-45DA-87F4-EB2DCF5B07A1 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 Dan,=20 That update is complete at = http://www.aiaahouston.org/adamo_astrodynamics/ = . Please do not = hesitate to send changes.=20 Douglas Yazell 832-366-5292 iPhone=20 douglas.yazell@me.com PS I met Steve Keough today at the weekly Friday BAND (Bay Area New = Democrats) lunch at Sawa Restaurant near 888 Bistro, and Sawa used to be = the Coliseum, etc. Steve is a candidate = for the Democratic Party = 2024 primary and plans to win that in order to challenge Ted Cruz later = in 2024. Steve=E2=80=99s father was one of the about 444 hostages in = Iran in about 1979. His late father was 6=E2=80=99 9=E2=80=9D. When = Steve was 8 years old, he and his father met President Johnson in the = White House. A photo was taken, but the cameraman tilted the camera up = to include his father, so little Steve is not in the photo. About four = years earlier Steve was enjoying a weekly trip in town to the public = library in a small and poor town in Vermont, and he looked forward to = the popcorn as much as the books. As he was enjoying popcorn outside, = black cars pulled up, then a car arrived with President Kennedy getting = out of it. =E2=80=9CHow is the popcorn? Is that good?=E2=80=9D Steve did = not answer, but he offered some popcorn to President Kennedy, who rubbed = his head as he walked on. So by the time Steve was 8, he met two = presidents. His dad was a teacher and then a school principal in a small = and poor town when Steve was growing up. He went with his dad to buy = pants for elementary school kids, using the school budget. Then he went = with his dad as they visited families before the school year started. = They were so poor, they would be bullied at school if they wore pants = with broken zippers, etc., so the new pants were passed out as needed.=20= Steve=E2=80=99s dad was, as I recall, principal of the American School = in Tehran. After the hostage taking, student records were needed for the = students when they applied to colleges in the USA and elsewhere. Paper = records were needed, of course. Steve arranged for a flight (an = airlliner?) with him on board to obtain those records. =20 As I recall, President Clinton appointed Steve to an advisory committee = assessing nuclear threats of all kinds.=20 On Aug 10, 2023, at 11:59 PM, Daniel Adamo wrote: ATIG Members- =20 The subject model computes rotation, nutation, and precession (RNP) = dynamics transforming coordinates between an Earth-fixed system such as = latitude/longitude/altitude and an inertial system such as the Earth = mean equator and equinox of epoch J2000.0. The Swift-based trajectory = design/modeling system I=E2=80=99ve been developing since 2017 uses data = files from JPL to provide precision Earth orientation transformations, = but these highly accurate files do not support times before year 1972. = In accurately reconstructing Apollo Program trajectories, it is = therefore necessary to perform precision RNP computations in Swift code. = The attached paper provides testing data demonstrating these = computations are sufficiently accurate for Apollo trajectory = reconstruction. Your comments on this material are invited. =20 -Dan =20 --Apple-Mail=_0E3859C5-85EF-45DA-87F4-EB2DCF5B07A1 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8 Dan, 

That update is complete at http://www.aiaahouston.org/adamo_astrodynamics/. Please = do not hesitate to send changes. 

Douglas Yazell
832-366-5292 iPhone 

PS
I met Steve Keough today at the weekly Friday BAND (Bay Area = New Democrats) lunch at Sawa Restaurant near 888 Bistro, and Sawa used = to be the Coliseum, etc. Steve is a candidate for the Democratic Party 2024 primary and = plans to win that in order to challenge Ted Cruz later in 2024. = Steve=E2=80=99s father was one of the about 444 hostages in Iran in = about 1979. His late father was 6=E2=80=99 9=E2=80=9D. When Steve was 8 = years old, he and his father met President Johnson in the White House. A = photo was taken, but the cameraman tilted the camera up to include his = father, so little Steve is not in the photo. About four years earlier = Steve was enjoying a weekly trip in town to the public library in a = small and poor town in Vermont, and he looked forward to the popcorn as = much as the books. As he was enjoying popcorn outside, black cars pulled = up, then a car arrived with President Kennedy getting out of it. =E2=80=9C= How is the popcorn? Is that good?=E2=80=9D Steve did not answer, but he = offered some popcorn to President Kennedy, who rubbed his head as he = walked on. So by the time Steve was 8, he met two presidents. His dad = was a teacher and then a school principal in a small and poor town when = Steve was growing up. He went with his dad to buy pants for elementary = school kids, using the school budget. Then he went with his dad as they = visited families before the school year started. They were so poor, they = would be bullied at school if they wore pants with broken zippers, etc., = so the new pants were passed out as needed. 

Steve=E2=80=99s dad was, as I = recall, principal of the American School in Tehran. After the hostage = taking, student records were needed for the students when they applied = to colleges in the USA and elsewhere. Paper records were needed, of = course. Steve arranged for a flight (an airlliner?) with him on board to = obtain those records.  

As I recall, President Clinton = appointed Steve to an advisory committee assessing nuclear threats of = all kinds. 





On Aug 10, 2023, at 11:59 PM, Daniel = Adamo <adamod@earthlink.net> wrote:

ATIG Members-
 
The = subject model computes rotation, nutation, and precession (RNP) dynamics = transforming coordinates between an Earth-fixed system such as = latitude/longitude/altitude and an inertial system such as the Earth = mean equator and equinox of epoch J2000.0.  The Swift-based = trajectory design/modeling system I=E2=80=99ve been developing since = 2017 uses data files from JPL to provide precision Earth orientation = transformations, but these highly accurate files do not support times = before year 1972.  In accurately reconstructing Apollo Program = trajectories, it is therefore necessary to perform precision RNP = computations in Swift code.  The attached paper provides testing = data demonstrating these computations are sufficiently accurate for = Apollo trajectory reconstruction.  Your comments on this material = are invited.
 
-Dan
 
<image001.jpg>
<EarthSupplementalRNPr0= .pdf>

= --Apple-Mail=_0E3859C5-85EF-45DA-87F4-EB2DCF5B07A1--