| Landmark |
|
A geographical feature, such as a segment of coastline, identified in image data (at one or more spectral bands) and used to locate instrument reference frame data on the Earth reference grid. |
|
Latency, Ground Data |
|
See Ground Latency. |
|
|
| Launch |
|
The period of time between lift off and the separation of the GOES-R Series satellite from the launch vehicle. |
|
| Launch and Orbit Raising (LOR) |
|
The launch and orbit raising (if needed) phase consists of the launch, transfer orbit operations, orbital maneuvers to the checkout station, appendage deployments, and spacecraft functional checkout. During the spacecraft functional checkout, spacecraft contractor engineers and operators complete checkout of the communication payload and those spacecraft subsystems, including redundant functions, which are going to be needed for payload tests. This phase begins at day L-1 and continues until the contractor performs an engineering handover to NASA. Launch vehicle/services will be provided by government. |
|
| Level 0 |
|
Reconstructed unprocessed instrument data at full resolution; any and all communications artifacts (e.g. synchronization frames, communications headers) removed. |
|
| Level 1a data |
|
Level 0 data with all supplemental information appended for use in subsequent processing. |
|
| Level 1b data |
|
Level 0 data with radiometric and geometric correction applied to produce parameters in physical units. |
|
| Level 2 data |
|
Derived environmental variables (e.g., sea surface temperature) at a comparable temporal and spatial resolution to the Level 1 source. |
|
| Level 2+ data |
|
All level 2 and higher products. |
|
| Level 3 data |
|
Data or retrieved environmental variables which have been spatially and/or temporally resampled (i.e. derived from Level 1 or 2). Such resampling may include averaging and/or compositing. |
|
| Level 4 data |
|
Model output or results from analyses of lower level data (i.e., data that arenot directly measured by the instruments, but are derived from these measurements). |
|
Level of Assembly (Space Segment) |
|
The environmental test requirements of GEVS generally start at the component or unit-level assembly and continue hardware/software build through the system level (referred to in GEVS as the payload or spacecraft level). The assurance program includes the part level. Validation testing may also include testing at the assembly and subassembly levels of assembly; for test record keeping these levels are combined into a “subassembly” level. The validation program continues through launch, and on-orbit performance. The following levels of assembly are also used for describing test and analysis configurations:
- Part: A hardware element that is not normally subject to further subdivision or disassembly without destruction of design use. Examples include resistor, integrated circuit, relay, connector, bolt, and gaskets.
- Subassembly: A subdivision of an assembly. Examples are wire harness and loaded printed circuit boards.
- Assembly: A functional subdivision of a component consisting of parts or subassemblies that perform functions necessary for the operation of the component as a whole. Examples are a power amplifier and gyroscope.
- Component or unit: A functional subdivision of a subsystem and generally a self contained combination of items performing a function necessary for the subsystem’s operation. Examples are electronic box, transmitter, gyro package, actuator, motor, battery. For the purposes of this document, “component” and “unit” are used interchangeably.
- Subsystem: A functional subdivision of a system consisting of two or more components. Examples are structural, attitude control, electrical power, and communication subsystems. Also included as subsystems of the payload are the science instruments or experiments.
|
|
| Level of Assembly (Ground Segment) |
|
A term that refers to a level of Ground Segment decomposition or integration. The order of the levels is as follows:
GOES-R System <> Ground Segment <> Element <> Subsystem <> Component |
|
| Limit Loads |
|
Defined as all worst case load conditions including temperature effects from the environments expected during all phases of the structure's service life including manufacturing, ground handling, transportation, environmental testing, integration, pre-launch, launch and on-orbit operations and storage. |
|
| Limited Life Items |
|
Hardware:
- That has an expected failure-free life that is less than the projected mission life, when considering cumulative development, operations and storage.
- Limited shelf life material used to fabricate hardware.
|
|
| Local Zenith Angle |
|
The angle between the local vertical and the line-of- sight of the spacecraft. |
|
