Publication of orbits derived from photoreduced Baker-Nunn observations

Orbital data derived from photoreduced Baker- Nunn observation

Development of high accuracy and resolution geoid and gravity maps

Precision satellite to satellite tracking can be used to obtain high precision and resolution maps of the geoid. A method is demonstrated to use data in a limited region to map the geopotential at the satellite altitude. An inverse method is used to downward continue the potential to the Earth surface. The method is designed for both satellites in the same low orbit

The earths gravity field to 16th degree and station coordinates from satellite and terrestrial data

Geodetic parameters of earth gravity field and satellite tracking station positions in geocentric reference fram

Revision of geodetic parameters

Laser data from nine satellites and 12 stations are combined with surface-gravity data to obtain spherical harmonics representing the geopotential complete through degree and order 18. This laser-data-only solution provides a reasonable improvement to the gravity field

A measurable effect of general relativity in satellite orbits

Relativistic corrections calculated for one way Doppler system used in calculating orbital velocit

America\u27s (Second) Best Idea: A Proposal for a Major Expansion of the National Park System

This Note will argue for a major expansion of the National Park Service and provide a framework for the implementation of such an expansion. Part I provides an overview of the National Park Service’s holdings and fundamental purpose and discusses how overcrowding negatively affects visitors, the resource, and the NPS mission, and argues for a stricter enforcement of the “impairment standard.” Part II outlines the way in which Congress and the president can create national parks. Part III proposes a major expansion of the national parks—both the expansion of existing park units and the creation of new ones—as the solution and discusses the legal, environmental, and social benefits of the proposal. Finally, Part IV discusses additional considerations for preserving the national parks, such as the provision of alternative transportation, the need for increased staffing, and the importance of pre-emptive management—all of which can help create a more equitable and sustainable National Park System for the future. This abstract has been taken from the author\u27s introduction

Satellite To Satellite Doppler Tracking (SSDT) for mapping of the Earth's gravity field

Two SSDT schemes were evaluated: a standard, low-low, SSDT configuration, which both satellites are in basically the same low altitude nearly circular orbit and the pair is characterized by small angular separation; and a more general configuration in which the two satellites are in arbitrary orbits, so that different configurations can be comparatively analyed. The standard low-low SSDT configuration is capable of recovering 1 deg X 1 deg surface anomalies with a strength as low as 1 milligal, located on the projected satellite path, when observing from a height as large as 300 km. The Colombo scheme provides an important complement of SSDT observations, inasmuch as it is sensitive to radial velocity components, while keeping at the same performance level both measuring sensitivity and measurement resolution

Station coordinates in the standard earth 3 system and radiation-pressure perturbations from ISAGEX camera data

Simultaneous and individual camera observations of GEOS 1, GEOS 2, Pageos, and Midas 4 obtained during the International Satellite Geodesy Experiment are utilized to determine station coordinates. The Smithsonian Astrophysical Observatory Standard Earth III system of coordinates is used to tie the geometrical network to a geocentric system and as a reference for calculating satellite orbits. A solution for coordinates combining geometrical and dynamical methods is obtained, and a comparison between the solutions and terrestrial data is made. The radiation-pressure and earth-albedo perturbations for Pageos are very large, and Pageos' orbits are used to evaluate the analytical treatment of these perturbations. Residual effects, which are probably of interest to aeronomists, remain in the Pageos orbits

Earth's gravity field to the eighteenth degree and geocentric coordinates for 104 stations from satellite and terrestrial data

Geodetic parameters describing the earth's gravity field and the positions of satellite-tracking stations in a geocentric reference frame were computed. These parameters were estimated by means of a combination of five different types of data: routine and simultaneous satellite observations, observations of deep-space probes, measurements of terrestrial gravity, and surface-triangulation data. The combination gives better parameters than does any subset of data types. The dynamic solution used precision-reduced Baker-Nunn observations and laser range data of 25 satellites. Data from the 49-station National Oceanic and Atmospheric Administration BC-4 network, the 19-station Smithsonian Astrophysical Observatory Baker-Nunn network, and independent camera stations were employed in the geometrical solution. Data from the tracking of deep-space probes were converted to relative longitudes and distances to the earth's axis of rotation of the tracking stations. Surface-gravity data in the form of 550-km squares were derived from 19,328 1 deg X 1 deg mean gravity anomalies

Geodetic research studies Final technical report

Geopotential surface measurement of ocean using altimeter dat