- API data.nasa.gov | Last Updated 2020-01-29T03:35:08.000Z
<p>This proposed work is to demonstrate that the already established ALD coating method can be applied to the X-ray mirror fabrication and is suitable to produce an additional thin layer on X-ray reflectors. All the soft X-ray mirrors previously flown employed a heavy metal coating, such as Ir, Au, and Pt, in order to increase the upper limit of their sensitive energy band beyond 10 keV. However, it is known that such a heavy element is not optimal for the softer X-ray reflection < ~7 keV. The heavy element has a high electron density, which is ideal to reflect X-rays, but also attenuates them during the reflection process. The heavy element also creates absorption edge structures in the mirror effective area energy response, particularly a big sharp drop around the L absorption edge around 2 keV. It has been suggested by many people that a thin light element layer, such as Ni, Cu, C, etc., on top of the heavy element can enhance the effective area as well as eliminate the L-edge structure. Only a very thin layer is required for this enhancement, but a segmented X-ray mirror contains thousands of reflectors inside. An additional complication tends to be avoided for the flight project. On the other hand, the ALD coating method can in principle coat many substrates simultaneously with precise thickness control. This will not take much cost and schedule of the flight project. In this task, we will use Al2O3 which can provide a stable and robust reflecting surface. We intend to demonstrate that the ALD can produce uniform thickness over the large surface area and among multiple reflectors in one coating run.</p>
- API data.nasa.gov | Last Updated 2019-12-12T23:52:16.000Z
The ERBE-like Footprint TOA Fluxes (ES-8) product contains 24 hours of instantaneous Clouds and the Earth's Radiant Energy System (CERES) data for a single scanner instrument, Flight Model 1 (FM1) on the Terra spacecraft . The ES-8 contains filtered radiances recorded every 0.01-second for the total (TOT), shortwave (SW), and window (WN) channels and the unfiltered SW, longwave (LW), and WN radiances. The SW and LW radiances at spacecraft altitude are converted to Top-of-the-Atmosphere (TOA) fluxes with a scene identification algorithm and Angular Distribution Models (ADMs) which are "like" those used for the Earth Radiation Budget Experiment (ERBE). The TOA fluxes, scene identification, and angular geometry are included on the ES-8. CERES is a key component of the Earth Observing System (EOS) program. The CERES instruments provide radiometric measurements of the Earth's atmosphere from three broadband channels. The CERES missions are a follow-on to the successful Earth Radiation Budget Experiment (ERBE) mission. The first CERES instrument (PFM) was launched on November 27, 1997 as part of the Tropical Rainfall Measuring Mission (TRMM). Two CERES instruments (FM1 and FM2) were launched into polar orbit on board the EOS flagship Terra on December 18, 1999. Two additional CERES instruments (FM3 and FM4) were launched on board EOS Aqua on May 4, 2002. The newest CERES instrument (FM5) was launched on board the Suomi National Polar-orbiting Partnership (NPP) satellite on October 28, 2011.
Wideband Autocorrelation Radiometer Receiver Development and Demonstration for Direct Measurement of Terrestrial Snow and Ice Accumulationdata.nasa.gov | Last Updated 2020-01-29T04:06:36.000Z
The seasonal terrestrial snow pack is an important source of water for many parts of the globe. Snow's high albedo, relative to the terrain in the absence of snow, is an important driver of Earth's energy balance, and long term changes to the statistics of the snow pack's properties are both a consequence and a cause of climate change. The global quantification of the amount of water in the snow pack reservoir is a long term objective of NASA's Earth Science Division. Thus far, the primary means of quantifying the amount of snow on the ground has been via the differential scatter-darkening mechanism, such as the 19 and 37 GHz brightness difference. While a 35+ year time series of passive microwave satellite data has been made, progress in understanding the scatter-darkened brightness signature of snow continues, especially for forested areas where vegetation scattering confounds the signature. This proposal looks to advance an alternative approach to using passive microwave to measure the snow accumulation. Wideband autocorrelation radiometry (WiBAR) is a technique wherein the electromagnetic propagation time across a layered media, such as snow pack or lake ice, can be remotely sensed. Thermal emission from the ground under the snow pack propagates up through the snow pack to the receiver. When the upper and lower surfaces of the snow pack are locally smooth, which is true at sufficiently long wavelengths, additional paths result from the reflection of the upward traveling wave from first the upper and then the lower surface of the snow pack. Arriving at the antenna, these waves are identical except for their amplitude and the time lag associated with the extra transit of the snow pack. This time lag is the observable. For sufficiently long wavelengths, the snow snow grains that cause the scattering are sufficiently deep in the Rayleigh region so as to be of minor importance. Unlike scatter darkening, where the microscopic properties of snow dominate the signal and the desired macroscopic properties are secondary, for WiBAR, the macroscopic properties of the snow depth is the most important parameter determining the signal, modified by the density (and thus it measures SWE), and the microscopic properties, responsible for the scattering, reduce the signal strength but do not alter the quantification of the accumulation. The bandwidth of the radiometer determines the minimum vertical extent that is observable. A wide bandwidth (several gigahertz) is desired for the relatively shallow snow covers encountered on Earth. We have demonstrated that this signal exists and can be observed both for a snow pack and for a fresh-water lake ice pack with ground-based observations. We have done this with a spectrum analyzer functioning as the radiometer receiver back-end: in the frequency domain, the delayed ray interferes with the direct ray to produce constructive maxima and destructive minima in the brightness spectra. But this technique is inherently slow, as the number of samples required is high and the instantaneous bandwidth is low. This frequency-domain approach is much too slow for spaceborne or even airborne observation. These observations also confirm the robustness of the approach to radio-frequency interference (RFI): since the observable is a time-delay and not a brightness magnitude, the narrow-band RFI does not mask the broadband WiBAR signature. We propose to develop a radiometer back-end that observes the entire spectrum of interest simultaneously, which will greatly reduce the observation time, possibly down to the order of milliseconds, which would make observations from a moving platform possible. We will then demonstrate the technological advancement in a direct comparison to the spectrum analyzer-based receiver measurement in a laboratory setting.
- API data.nasa.gov | Last Updated 2020-01-29T02:13:03.000Z
During Phase 1, we investigated a number of blade designs for 2, 3, and 4 blade sampler geometries. We found that blades with small apex angles can penetrate harder formations with much lower energies. We propose to develop a 3 or 4 blade design for sampling much harder (4 MPa and more) material. During Phase 2 we will initially perform more extensive blade testing to determine optimum design, we will also investigate use of pyros to deploy blades, breadboard and test force neutral deployment and investigate One Resettable vs Multiple Samplers architectures. These studies will lead to 3 vs 4 blade architecture study (Tetrahedron Comet Sampler or TeCos and Pyramid Comet Sampler or PyCoS) and downselection. The TRL 4 TeCoS or PyCoS will then be build and tested. The results will be used to design TRL 5 system. The TRL prototype will then be build and tested in a range of analog materials from 5 DOF arm to mimic 2-3 DOF TAG arm and spacecraft movement.
- API data.nasa.gov | Last Updated 2019-12-12T23:52:01.000Z
The Clouds and Radiative Swath (CRS) product contains one hour of instantaneous Clouds and the Earth's Radiant Energy System (CERES) data for a single scanner instrument. The CRS contains all of the CERES SSF product data. For each CERES footprint on the SSF the CRS also contains vertical flux profiles evaluated at four levels in the atmosphere: the surface, 500-, 70-, and 1-hPa. The CRS fluxes and cloud parameters are adjusted for consistency with a radiative transfer model and adjusted fluxes are evaluated at the four atmospheric levels for both clear-sky and total-sky. CERES is a key component of the Earth Observing System (EOS) program. The CERES instruments provide radiometric measurements of the Earth's atmosphere from three broadband channels. The CERES missions are a follow-on to the successful Earth Radiation Budget Experiment (ERBE) mission. The first CERES instrument (PFM) was launched on November 27, 1997 as part of the Tropical Rainfall Measuring Mission (TRMM). Two CERES instruments (FM1 and FM2) were launched into polar orbit on board the EOS flagship Terra on December 18, 1999. Two additional CERES instruments (FM3 and FM4) were launched on board EOS Aqua on May 4, 2002. The newest CERES instrument (FM5) was launched on board the Suomi National Polar-orbiting Partnership (NPP) satellite on October 28, 2011.
- API data.nasa.gov | Last Updated 2020-01-29T04:58:40.000Z
A microgravity-compatible Continuous Brine Evaporation Cartridge (CBEC) is proposed for greater than 95% water recovery from highly contaminated wastewater without concern for precipitation of organic and inorganic solids. The CBEC utilizes a small, counter flow evaporation chamber and heat exchange technologies, which reduce Equivalent System Mass (ESM) for water recovery via an evaporation system. A gas phase catalytic oxidizer converts organic contaminants in the moist air stream to carbon dioxide and water. The CBEC system dramatically lowers consumables and reduces long-term waste storage requirements compared to a traditional wick evaporation system. Highly contaminated wastewater streams such as urine, hygiene water, and RO brines are major wastewater streams for the CBEC. The Phase I project will focus on development of the counter flow wick evaporation cartridge and the catalytic oxidizer. The Phase II will incorporate thermal efficiency and mechanical durability to improve ESM of the CBEC system and result in delivery of 2 prototype systems, one large scale and the other for testing in microgravity. These efforts will be the foundation for the design and construction of a flight ready prototype for use on the International Space Station. The CBEC process will exceed the goal of 95% water recovery by 2022 set forth by NASA in the space technology roadmap.
- API data.nasa.gov | Last Updated 2020-01-29T01:59:06.000Z
The proposed Wireless, passive, SAW sensor system operates in a multi-sensor environment with a range in excess of 45 feet. This proposed system offers unique features in two (2) important areas. The first is in the development of a new sensor type, a strain gauge that is based on OFC techniques and implemented with the low loss characteristics of SAW Unidirectional transducers. The second is in the design of an integrated interrogator system that has DSP-based embedded signal processing. Interrogator will also be capable of rapidly performing multiple interrogations which can them be used to make ibration measurements or averaged to extend the operational range of the system. This proposal extends the Phase I and previous work in two major areas; developing a SAW strain sensor, and dramatically increasing interrogation range, which is applicable to both the new strain sensors and the previously developed temperature sensors. In order to increase SAW sensor range, sensitivity and accuracy, the most important device parameters were identified and initial investigation begun in Phase I and will be put into practice in Phase II. To reduce SAW sensor loss and minimize multi-transit acoustic echoes, low loss unidirectional studies were initiated. Phase I produced three alternative low-loss approaches that will be evaluated in the Phase II work. Success will lower the insertion loss by approximately 15 dB, and multi-transit echoes are predicted to be less than -40 dB from the main signal; doubling the system range and reducing the sensors self-noise. Advanced coding techniques were investigated in Phase I that have led to longer delay path lengths, and shorter codes with less inter-sensor interference. During Phase II, the interrogator will improve the following critical capabilities: onboard-fully-integrated DSP, extended connectivity options to customer's computer, and rapid interrogation capabilities. This will allow vibration sensing and signal integration.
- API data.nasa.gov | Last Updated 2019-12-12T23:50:54.000Z
The Cloud-Aerosol Transport System (CATS), launched on January 10, 2015, is a lidar remote sensing instrument that will provide range-resolved profile measurements of atmospheric aerosols and clouds from the International Space Station (ISS). CATS is intended to operate on-orbit for at least six months, and up to three years. CATS will provide vertical profiles at three wavelengths, orbiting between ~230 and ~270 miles above the Earth's surface at a 51-degree inclination with nearly a three-day repeat cycle. For the first time, it will allow scientist to study diurnal (day-to-night) changes in cloud and aerosol effects from space by observing the same spot on Earth at different times each day. CATS Level 2 Layer data product containing geophysical parameters derived from Level 1 data, at 60m vertical and 5km horizontal resolution.
- API data.nasa.gov | Last Updated 2019-12-12T23:52:29.000Z
The Monthly Gridded Cloud Averages (ISCCP-D2like-Mrg) data product contains monthly and monthly 3-hourly (GMT-based) gridded regional mean cloud properties as a function of 18 cloud types, similar to the ISCCP D2 product, where the cloud properties are stratified by pressure, optical depth, and phase. The Mrg product combines daytime cloud properties from Terra-MODIS (10:30 AM local equator crossing time LECT), Aqua-MODIS (1:30 PM LECT), and geostationary satellites (GEO) to provide the most diurnally complete daytime ISCCP-D2like product. The GEO cloud properties have been normalized with MODIS for diurnal consistency. The CERES MODIS-derived cloud properties are not the official NASA MODIS cloud retrievals, but are based on the CERES cloud working group retrievals that are also available in other CERES products. The CERES MODIS-derived cloud properties provide coverage from pole to pole. The 3-hourly GMT-based GEO cloud properties come from five satellites at 8km nominal resolution with coverage limited to to . The GEO daytime cloud retrievals incorporate only a visible and IR channel common to all geostationary satellites for spatial consistency. The geostationary calibration is normalized to Terra-MODIS. Each ISCCP-D2like file covers a single month. Clouds and the Earth's Radiant Energy System (CERES) is a key component of the Earth Observing System (EOS) program. The CERES instruments provide radiometric measurements of the Earth's atmosphere from three broadband channels. The CERES missions are a follow-on to the successful Earth Radiation Budget Experiment (ERBE) mission. The first CERES instrument (PFM) was launched on November 27, 1997 as part of the Tropical Rainfall Measuring Mission (TRMM). Two CERES instruments (FM1 and FM2) were launched into polar orbit on board the EOS flagship Terra on December 18, 1999. Two additional CERES instruments (FM3 and FM4) were launched on board EOS Aqua on May 4, 2002. The newest CERES instrument (FM5) was launched on board the Suomi National Polar-orbiting Partnership (NPP) satellite on October 28, 2011.
- API data.nasa.gov | Last Updated 2019-12-12T23:59:27.000Z
The MODIS/Aqua Atmospherically Corrected Surface Reflectance 5-Min L2 Swath 250m, 500m, 1km (MYD09) product is computed from the MODIS Level 1B land bands 1, 2, 3, 4, 5, 6, and 7 (centered at 648 nm, 858 nm, 470 nm, 555 nm, 1240 nm, 1640 nm, and 2130 nm, respectively). The product is an estimate of the surface spectral reflectance for each band as it would have been measured at ground level if there were no atmospheric scattering or absorption. The surface-reflectance product is the input for product generation for several land products: vegetation Indices (VIs), Bidirectional Reflectance Distribution Function (BRDF), thermal anomaly, snow/ice, and Fraction of Photosynthetically Active Radiation/Leaf Area Index (FPAR/LAI).