• Data Set Overview
• =================

This Data Set consists of Voyager 2 Neptune Encounter Ephemeris Data relative to the Sun in both Cartesian and Spherical Heliographic Coordinates for the Time Period when Voyager was near Neptune but not within its Magnetosphere.

The Magnetospheric Gap in this Data Set occurs from 1989-08-25 02:00:00 to 1989-08-26 00:00:00.

The Spacecraft Position Vectors are given in Neptune Longitude System (NLS) Coordinates in this Interval. The Position Vectors are given every 48 s. The Units of the Vector Components are AU and Degrees. Vectors are stored as 4-byte Floating Point Values.

The Heliographic Coordinate System is a Heliocentric System defined in the Reference Epoch of 1950. The Unit Vectors which define the Coordinate System are as follows:

• Heliographic Cartesian Coordinates
• ==================================

• X points away from the Sun toward the Ascending Node, in the Solar Equatorial Plane
• Y completes the right-handed Set, Y = X ⨯ Z
• Z points along the Spin Axis of the Sun, positive above the Equatorial Plane

+------------------------------------------+
| Parameter Characteristics | Value |

| Processing Level ID | 4 |
| Software Flag | Y |
| Processing Start Time | UNK |
| Processing Stop Time | UNK |
| Native Start Time | 11295:23:001 |
| Native Stop Time | 11505:59:001 |
+------------------------------------------+

• Parameters

• ==========

• Data Set Parameter POSITION VECTOR

• ==================================

A Position Vector is a Triad that describes the Location of a Point in three dimensional Space relative to some Origin.

+--------------------------------------------------+
| Parameter Characteristics | Value |

| Data Set Parameter Name | POSITION VECTOR |
| Data Set Parameter Unit | AU OR DEGREES |
| Sampling Parameter Name | TIME |
| Sampling Parameter Unit | SECONDS |
| Sampling Parameter Resolution | 96 |
| Sampling Parameter Interval | 48 |
| Minimum Available Sampling Int | 48 |
+--------------------------------------------------+

• Source Instrument Parameters
• ============================

N/A

• Measurement Information
• =======================

N/A

• Processing

• ==========

• Processing History

• ==================

+------------------------------------------------------------------+
| Parameter Characteristics | Value |

| Source Data Set ID | N/A |
| Software | UNK |
| Product Data Set ID | VG2-N-POS-5-SUMM-HGCOORDS-48SEC-V1.0 |
+------------------------------------------------------------------+