NavList:

I find the original subject "Himalayas move the Zenith" most interesting, owing to prior 1980s requirements analysis work with IBM On-Board Shuttle (OBS) Flight Software (FSW) for the Primary  Avionics Software System (PASS), for the Navigation (NAV) and Inertial Measurement Unit (IMU) principal functions.  Rather than post from memory, I asked the following in the Chrome browser (AI Mode):  What is a good reference for the gravity parties used at Kennedy Space Center to determine the precise latitude, longitude, and altitude for the Space Shuttle Navigation Initialization data at the launch pads?

I was pleasantly surprised with the following answer (with the exception of the GPS references, as Navstar 1 was not launched until 1978):

"A primary reference for the technical data regarding "gravity parties"—the precision gravity and geodetic surveys at Kennedy Space Center (KSC)—is NASA Technical Report 19830043154, "Navigation of the Space Shuttle." This document describes how the Inertial Measurement Unit (IMU) was initialized at the moment of launch using data from high-precision surveys conducted at the launch pads. 

• Precise Geodetic Coordinates: Accurate latitude and longitude for the exact position of the IMUs on the pad.
• Altitude/Elevation: The specific height above sea level for the hardstand—48 feet for Pad A and 55 feet for Pad B—used for vertical state vector initialization.
• Deflection of the Vertical: The deviation of the local gravity vector from the ellipsoidal normal, which was essential for fine-tuning the IMU's inertial alignment. 

• NASA Space Shuttle News Reference (1981): Provides foundational details on the Shuttle mission profile and launch pad infrastructure.
• Navigation of the Space Shuttle (1983): The authoritative technical report on how survey data was utilized for onboard state vector and attitude measurements.
• Shuttle Navigation Overview (1982): Covers IMU management and the transformation functions that integrated pad survey data into the navigation software.
• Space Shuttle Navigation In The GPS Era (2000): Discusses the transition from traditional IMU-only initialization (based on these gravity surveys) to GPS-augmented systems."