The Role of Small Satellites in NASA and NOAA Earth Observation Programs (2000) / Chapter Skim
Currently Skimming:
3 Payload Sensor Characteristics
3 Payload Sensor Characteristics
Pages 22-30
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 22... ...
It follows then that the smallest launch vehicle and smallest spacecraft bus that can accommodate a given mission sensor payload will generally yield the lowest mission space segment costs. Advances in sensor technology that can reduce instrument size, mass, and power consumption thus provide considerable leverage and are a frequent objective of sensor technology development efforts, which also aim at producing new or improved measurement capabilities and/or lowered costs.
|
From page 23... ...
outgassing Specific accommodation requirements vary widely depending on the type of payload instrument, with highresolution, broad-swath, electro-optical multispectral imagers being the most demanding in terms of size, mass, data rate, and pointing accuracy and stability. Pointing and stability is often a differentiating factor between spacecraft designed to carry communication payloads and those designed to carry remote sensing payloads, the latter typically having more demanding requirements (see Chapter 4~.
|
From page 24... ...
, which are facility class instruments in the EOS program, have volumes and masses of 2.7 m3/421 kg and 2.0 m3/ 229 kg, respectively. Accommodation requirements for representative EOS and NPOESS sensors are tabulated in Table 3.1.
|
From page 25... ...
The METOP is a joint undertaking of the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) , the European Space Agency (ESA)
|
From page 26... ...
With proper funding to enable them, advances in sensor technology and processes should continue to improve performance, cost, size, mass, and power parameters to suit mission objectives. FUTURE SENSOR DESIGNS: IMPLICATIONS OF ADVANCED TECHNOLOGIES Size and Design Constraints2 The "trade space" for the design and sizing of payload instruments is established by four types of constraints: fundamental, technological, mission, and programmatic (see Box 3.21.
|
From page 27... ...
67.7 12.5 NOTE: EOS data are actual costs; NPOESS data are target costs. SOURCES: EOS data Michael King, NASA Goddard Space Flight Center; NPOESS sensor cost data Stan Schneider, National Oceanic and Atmospheric Administration NPOESS Integrated Program Office.
|
From page 28... ...
Curves such as these can be misleading, however, because "resolution" is not meaningful unless defined in terms of an equivalent modulation transfer function or point spread function. Indeed, there could be a four-to-one difference in aperture diameter for different sensors all purported to have the same spatial resolution, as denoted by the extent of the design range bar in Figure 3.4.
|
From page 29... ...
Different approaches to partitioning measurements among different instruments and satellites can have significant effects on the size/mass/power of payload sensor designs and their corresponding host spacecraft. This becomes the classic trade-off between fewer, highly capable multipurpose instruments versus a greater number of smaller, simpler, more specialized instruments tailored for specific measurements.
|
From page 30... ...
SUMMARY Sensor design should flow from measurement requirements and is best performed as an iterative process between designers and the science community within the constraints set by fundamental physics, the state of the technology, and cost. The size of payload sensors affects the design of the entire space segment and establishes the scale of the spacecraft and launch vehicle.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.