Harris is currently developing different types of imaging hyperspectral instruments for CubeSat and other small satellite applications. All of these instruments utilize Fourier Transform Spectrometer (FTS) interferometer technology, which has been proven on larger space instruments for NASA and NOAA. Most of these instruments are aimed at remote sensing of the earth from low orbit. One example is HyperCube™, which is a hyperspectral mid-wave infrared (MWIR) instrument compatible with 6U CubeSats capable of collecting vertical moisture profiles and three-dimensional winds in the earth’s atmosphere. Another example is Harris’ HyperStare, which is a larger-aperture imaging FTS instrument that provides improved sensitivity and spatial resolution for detection of trace greenhouse gases in the atmosphere. This paper will provide design summaries and performance capabilities of each of these new instrument types. It will also discuss Harris’ newly developed ground station capability for operating small constellations of small satellites. In addition, new FTS technologies that may be suitable for future small satellites will be discussed.
Global measurements of vertically resolved atmospheric wind profiles offer the potential for improved weather forecasts and superior predictions of atmospheric wind patterns. Harris’ HyperCube constellation of twelve 6U hyperspectral CubeSats can provide measurements of global tropospheric wind profiles from space at very low cost. It is a commercially funded enterprise in which the data from the satellites is provided to users on a subscription basis. This requires that the design of each satellite be optimized for minimum cost, yet with a reasonably long service life. This paper will focus on the design, operations, and projected performance of the HyperCube system.
The Cross-track Infrared Sounder (CrIS) is one of the mission-critical instruments onboard the National Polar-orbiting Operational Environmental Satellite System (NPOESS). CrIS develops vertical profiles of moisture, temperature, and pressure in the earth's atmosphere by measuring upwelling atmospheric infrared radiation at very high spectral resolution. This paper describes initial test results for the CrIS Engineering Development Unit #3 (EDU3).
The Cross-track Infrared Sounder (CrIS) is one of the mission-critical instruments onboard the National Polar-orbiting Operational Environmental Satellite System (NPOESS). CrIS develops vertical profiles of moisture, temperature, and pressure in the earth’s atmosphere by measuring upwelling atmospheric infrared radiation at very high spectral resolution. This paper presents the current design status and performance projections of the CrIS instrument, which is approaching a Critical Design Review. Preliminary results from tests of an Engineering Development Unit will also be presented.
It is important in any remote sensing radiometer to identify and characterize the noise and error sources of the radiometer. At ITT, we have produced a number models to characterize noise and its impacts. The latest noise model is for the Cross-track Infrared Sounder (CrIS) instrument which is part the National Polar-orbiting Operational Satellite System (NPOESS). The required accuracy of the instrument demands identifying and characterizing the noise and random error sources to lower the risk of poor instrument performance. This paper lists the sources of noises and random errors identified in the CrIS sensor and compares model predictions to measurements from the first CrIS Engineering Development Unit (EDU).
The crosstrack IR Sounder (CrIS) is one of the key sensors now under development for the National Polar-orbiting Operational Environmental Satellite System program, which is the follow-on to the current DMSP and POES meteorological satellite systems. CrIS is a interferometric sounding sensor which accurately measures upwelling earth radiances at very high spectral resolution, and uses this data to construct vertical profiles of atmospheric temperature, moisture and pressure. These profiles are also called Environmental Data Records, or EDRs. The purpose of this paper is to describe the top level trade studies that led to the selection of the overall CrIS sensor design. Most of these trade studies involved a tradeoff between system performance and relative system cost. This paper discusses how EDR performance was determined for different trade study options, and review the key design and cost tradeoffs that led to the selection of the CrIS design.
For a complex remote sensor like the NPOESS Crosstrack Infrared Sounder (CrIS), the process of requirements flowdown is extremely important to the success of the project. When there is both an algorithm and a sensor, the task of allocating requirements between the sensor and the algorithm becomes a challenge. This is where the use of system models and simulations has been an invaluable tool. Complex requirements such as radiometric uncertainty and Instrument Line Shape (ILS) uncertainty have utilized system models and simulations for the allocation of requirements. For radiometric uncertainty the sensor model in conjunction with the algorithm which handles the calibration of the sensor was used to assess the contribution of parameters such as component and detector temperature stability on radiometric uncertainty. Variation of the parameter values within the sensor model allowed us to compute the impact on radiometric uncertainty and allocate requirements appropriately. Examples of how the model and simulations were used to develop requirements for the CrIS radiometric uncertainty will be presented. For the assessment of ILS uncertainty a model for predicting the ILS of a Michelson interferometer was employed. The model calculates the ILS and associated spectral shift based upon a set of input parameters. By varying the input parameters the sensitivity of the ILS to the specific parameters could be determined and used to allocate the requirements from a top level down to the module level. A description of the model, the input parameters and results for the CrIS requirements development will be presented.
The Crosstalk Infrared Sounder (CrIS) is one of the key sensors now under developed for the National Polar-orbiting Operational Environmental Satellite System program, which is the follow-on to the current DMSP and POES meteorological satellite systems. CrIS is a interferometric sounding sensor which accurately measures upwelling earth radiances at very high spectral resolution, and uses this data to construct vertical profiles of atmospheric temperature, moisture and pressure. The purpose of this paper is to describe the CrIS system design, discuss key trade studies that led to selection of the design, discuss risk reduction demonstrations that were performed to confirm the readiness of the technologies used in the CrIS design, and summarize the key performance capabilities of the CrIS system.
Proc. SPIE. 4131, Infrared Spaceborne Remote Sensing VIII
KEYWORDS: Long wavelength infrared, Short wave infrared radiation, Detection and tracking algorithms, Interferometers, Sensors, Calibration, Infrared radiation, Data conversion, Printed circuit board testing, Temperature metrology
The Crosstrack Infrared Sounder (CrIS) is one of the key sensors now under development for the National Polar- orbiting Operational Environmental Satellite system (NPOESS) program, which is the follow-on to the current DMSP and POES meteorological satellite systems. CrIS is a interferometric sounding sensor which accurately measures upwelling earth radiances at very high spectral resolution, and uses this data to construct vertical profiles of atmospheric temperature, moisture and pressure. The purpose of this paper is to examine small modifications to the CrIS design that enable it to be used for other applications where improved radiometric uncertainty is required. Modifications include changes to the onboard calibration target and onboard calibration systems, as well as enhancements to ground calibration algorithms that remove additional sources of radiometric error. An assessment is also made of the level of improvement in radiometric uncertainty that can be expected.
Development of space-qualified Fourier Transform Spectrometer (FTS) systems for long-life operational space missions requires development of new technologies. ITT Industries has been developing these new FTS technologies for the past 5 years, in anticipation of their use in FTS systems for operational meteorological satellites and other long-life space applications. Our objectives are to identify FTS technologies that have important mission advantages, design and build new components using these technologies, and prove the new technologies in a complete FTS interferometer technology testbed. This paper describes the process used at ITT to identify and develop these new technologies, the Dynamically Aligned Porch Swing (DAPS) interferometer technology testbed used to prove the new technologies, characterization tests of the DAPS used to verify the performance of the new technologies, and space qualification efforts now underway to verify that the new technologies can survive space environments.
More accurate weather forecasting requires improvements in vertical temperature profiling.T He increase in vertical temperature resolution along with wind distributions will provide important information on vertical motion fields for Mesoscale weather predictions. Such information is particularly valuable for short-term forecasts and storm tracking. New techniques beyond what can be achieved with the current filter wheel sounders are required. A Michelson interferometer is proposed for the next generation of GOES Sounders. The interferometric spectrometer will greatly increase the spectral resolution of the sounder over the filter wheel instruments, improving its ability to measure temperature and water vapor profiles. This paper describes the current baseline design for the interferometer-equipped GOES Sounder, known as the GOES High-Resolution Interferometric Sounder.