history|0|V|1|History And Background|Provides an overview of the history of ocean measurement, and the role TOPEX/Poseidon plays in that evolution.|
earlier|1|V|1|Successor To Previous Oceanographic Missions|Outlines the design and purpose of TOPEX/Poseidon, based upon three previous ocean measuring satellites: GEOS-3, Seasat and Geosat.|
global|1|V|1|Part Of A Global Oceanographic Effort|Provides a description of TOGA and WOCE, two earth-based ocean measurement systems designed to complement the data obtained from space by TOPEX/Poseidon.|
joint|1|H|1|TOPEX/Poseidon Is A Joint Effort|Summarizes how TOPEX/Poseidon, once two separate ocean mapping missions, is now a cooperative mission between the USA and France.|
contrib|1|V|1|TOPEX/Poseidon's Contribution|Explains the purpose of TOPEX/Poseidon, the accuracy of its measurement system, the data that will be acquired during the mission, and its significance.|
mission|0|H|2|Mission Description|Provides access to sections describing the goals of the mission, its systems and the mission phases.|
goals|1|V|2|Science Objectives and Goals|Describes the main objective of TOPEX/Poseidon and what will be achieved when the objective is met.|
systems|1|V|2|Systems|Provides access to sections describing the Launch, Spacecraft, and Ground Systems.|
vehicle|2|V|2|Launch Vehicle System|Describes the Launch Vehicle System, its components and how it was managed.|
ariane|3|L|2|Ariane 42P Launch Vehicle|Describes the Ariane 42P rocket, which was used to place TOPEX/Poseidon into orbit.|
launch|3|V|2|Launch of TOPEX/Poseidon|Describes the launch phase of the mission.|
satsys|2|V|2|Spacecraft Systems|Describes the four systems that comprise the Spacecraft System.|
grndsys|2|V|2|Ground Systems|Describes the five systems that make up TOPEX/Poseidon's ground system.|
phases|1|V|2|Mission Phases|Outlines the five mission phases.|
sc|0|H|3|Spacecraft|Provides access to sections describing the spacecraft and its sensors, satellite statistics, health, and component failures and anomalies.|
config|1|H|3|Configuration of TOPEX/Poseidon|Provides access to sections describing the spacecraft and its sensors.|
nadir|2|H|3|Nadir Side of the Spacecraft|Displays a view of the nadir side of the spacecraft. From here details about the sensors and flight hardware may be explored.|
zenith|2|H|3|Zenith Side of the Spacecraft|Displays a view of the zenith side of the spacecraft. From here details about the sensors and flight hardware may be explored.|
port|2|H|3|Port Side of the Spacecraft|Displays a view of the port side of the spacecraft. From here details about the sensors and flight hardware may be explored.|
starbrd|2|H|3|Starboard Side of the Spacecraft|Displays a view of the starboard side of the spacecraft. From here details about the sensors and flight hardware may be explored.|
bow|2|H|3|Bow End of the Spacecraft|Displays a view of the bow end of the spacecraft. From here details about the sensors and flight hardware may be explored.|
stern|2|H|3|Stern End of the Spacecraft|Displays a view of the stern end of the spacecraft. From here details about the sensors and flight hardware may be explored.|
mms|2|H|3|Multimission Modular Spacecraft|Describes the TOPEX/Poseidon spacecraft bus and why it was selected for use by mission designers.|
im|2|H|3|Instrument Module|Describes the instrument module that houses the sensors aboard TOPEX/Poseidon.|
gpsa|2|H|3|Global Positioning System Antenna|Describes the Global Positioning System, including the satellite system, GPS Antenna, and GPS receiver.|
hga|2|L|3|High Gain Antenna|Provides information on TOPEX/Poseidon's high gain antenna, its configuration during and after launch, and how it is used for communications and data transfer.|
zoa|2|H|3|Zenith Omni Antenna|Describes the zenith omni antenna and its use as a backup for the high gain antenna.|
doris|2|H|3|DORIS Antenna|Gives an explanation of what DORIS is, how it works, and the role it plays in precision orbit determination.|
noa|2|L|3|Nadir Omni Antenna|Describes the nadir omni antenna and its use as a backup for the high gain antenna.|
alt|2|L|3|Altimeter Antenna|Describes the primary altimeter and how it is used for data collection. Also addressed is the CNES altimeter, its characteristics, and purpose as a flight experiment.|
lra|2|L|3|Laser Retroreflector Array|Describes the Laser Retroreflector Array, its configuration, operation, use and accuracy.|
solar|2|H|3|Solar Array|Describes the solar panels, their specifications and the part they play in the power system aboard the spacecraft.|
css|2|L|3|Course Sun Sensors|Describes how sun sensors are sometimes used to obtain an orientation for TOPEX/Poseidon that will provide maximum solar power.|
louvers|2|L|3|Thermal Louvers|Discusses how thermal louvers are used to dispose of excessive heat and prevent the spacecraft from overheating.|
esam|2|H|3|Earth Sensor Assembly Module|Explains the operation of the ESAM sensors and the role they play in determining spacecraft orientation.|
sccu|2|L|3|Signal Conditioning and Control Unit|Explains how the Signal Conditioning and Control Unit assists in the deployment of parts of the spacecraft stowed for launch.|
urad|2|L|3|Microwave Radiometer|Describes the function of the microwave radiometer.|
cdh|2|H|3|Command and Data Handling Module|Describes how the Command and Data Handling Module supports the spacecraft and its sensors.|
obc|3|H|3|On-board Computer|Describes the function of the on-board computer.|
record|3|H|3|Tape Recorders|Describes how the tape recorders function as part of data handling.|
powmod|2|H|3|Power Module|Describes the power module and its relation to spacecraft subsystems and components.|
battery|3|H|3|Batteries|Describes the batteries on board TOPEX/Poseidon and their function.|
acm|2|H|3|Attitude Control Module|Describes how the Attitude Control Module contributes to determining spacecraft orientation, and assists in orbital correction maneuvers.|
wheel|3|H|3|Reaction Wheels|Describes how the reaction wheels are configured on TOPEX/Poseidon, and how they work to correct the orientation of the spacecraft.|
star|3|H|3|Star Trackers|Discusses how star trackers operate and their use in spacecraft orientation.|
dfss|3|L|3|Digital Fine Sun Sensor|Summarizes how the fine sun sensors use the sun to assist in orbit and orientation adjustments.|
propmod|2|H|3|Propulsion Module|Explains the configuration of the propulsion module and how it is used.|
rem|3|H|3|Rocket Engine Modules|Describes the configuration of the thrusters or rocket engine modules, their power capacity, how they work, and how they are used.|
stats|1|H|3|TOPEX/Poseidon Vital Statistics|Provides statistics on mass, dimensions, power, data storage, memory and communication rates for TOPEX/Poseidon.|
health|1|L|3|Satellite Health|Describes the steps taken by designers and project personnel to minimize impacts of projected deterioration of TOPEX/Poseidon.|
failure|2|H|3|Component Failures and Anomalies|Documents the sources of failures and anomalies that have occurred for TOPEX/Poseidon from launch through the primary observational phase.|
measure|0|L|4|How The Measurement System Works|Describes the use and accuracy of the altimeter on board TOPEX/Poseidon, and discusses precision orbit determination as a key to accurate measurement of the world's oceans. A definition of the standard orbit for TOPEX/Poseidon is provided.|
process|1|V|4|Measurement Process|Provides more detail on the use of the radar altimeter. Introduces the radiometer and its use for correcting errors in the altimeter's return signal.|
locate|1|V|4|Locating TOPEX/Poseidon in Space|Describes the three methods used to obtain the position of TOPEX/Poseidon: Laser Ranging, DORIS, and the Global Positioning System.|
ops|0|H|5|Mission Operations|Lists eight areas of mission operations and provides links to additional information.|
plan|1|V|5|Mission Planning And Sequencing|Gives a high-level description of the types of activities performed by the MPST.|
nav|1|V|5|Navigation|Provides a high-level description of the types of activities performed by the Navigation team.|
pod|1|V|5|Precision Orbit Determination|Discusses precision orbit determination and the implementation of the Global Positioning System as a flight experiment.|
verify|1|V|5|Altimeter Verification|Explains how instruments on board an ocean platform are used as a double check for the accuracy of instruments on board TOPEX/Poseidon.|
perform|1|V|5|Satellite Performance Analysis|Presents a high-level description of the types of activities performed by the SPAT during the assessment and observational phases of the mission.|
control|1|V|5|Flight Control|Provides a high-level description of the types of activities performed by the FCT and how they stay in communication with the spacecraft.|
sdp|1|V|5|Science Data Processing|Provides a high-level description of the types of activities performed by the SDT, what science products are generated, and how they are distributed.|
learned|0|H|6|What We've Learned|Discusses why there is a need for a project like TOPEX/Poseidon, provides an overview of what has been learned from the data, and gives practical applications for this information.|
elnino|1|V|6|El Nino|Describes the El Nino event, its impact upon global weather and the part TOPEX/Poseidon is playing in predicting future events.|
climate|1|V|6|Global Climate|Explains the interrelationship between global climate and fluctuations in sea-level tracked by TOPEX/Poseidon.|
eddies|1|V|6|Eddies|Defines eddies, their similarity to atmospheric "weather", role in earth's climate, and impact on human pursuits.|
tides|1|V|6|Tides|Explores the process of tides and how by understanding them we may understand many oceanic and geodetic processes.|
ocean|1|V|6|Global Ocean Circulation|Addresses how winds, heat transport through the oceans, the rotation of the earth, and the Coriolis force all impact ocean circulation, which in turn affects local and global climate.|
sd|0|H|7|Science Data|Outlines the means by which data are produced, and provides information on how it may be obtained.|
dataflo|1|V|7|Data Flow|Summarizes how raw data are obtained, corrected, processed, validated and archived.|
product|1|V|7|Data Products|Provides access to information on six data sets generated from data taken by TOPEX/Poseidon.|
dot|2|V|7|Ocean Topography|Defines ocean topography and its relationship to systems of currents in the oceans.|
surface|2|V|7|Sea-Surface Variability|Discusses changes in sea level, their relationship to heat transport and atmospheric winds, and explores El Nino as an example of extreme fluctuation in sea level.|
waves|2|V|7|Significant Wave Height|Explains how radar can be used to collect data on wave height. Explores the relationship between wind speed and wave height and how this relationship may be used to forecast changes in ocean waves.|
wind|2|V|7|Wind Speed|Presents an illustration of the wind speed data set and illustrates how TOPEX/Poseidon data on waves also reflects information on winds.|
water|2|V|7|Precipitable Water Vapor|Details how the radiometer on board TOPEX/Poseidon is used to gather information on water vapor content. This information is used to correct measurements from the radar altimeter and to enhance our understanding of weather and climate change.|
tec|2|V|7|Total Electron Content|Details how the radiometer is used to gather information on total electron content in the earth's atmosphere. A sample of this dataset is provided within this section.|
or|1|V|7|Outreach|Offers specific information on points of contact through which additional information on TOPEX/Poseidon, and data provided by the spacecraft may be obtained.|
