The Vertical Temperature Profile Radiometer (VTPR) was an operational 8-channel infrared sounding system mounted on the NOAA-2 through NOAA-5 spacecraft. The instrument was a predecessor of the High-Resolution Infrared Radiation Sounder (HIRS) on the continuing NOAA polar orbiting satellite series. The VTPR measurements covered more than six years of data from late 1972 to early 1979. Major work has been done to clear erroneous data records. Theoretical biases between similar channels of VTPR and HIRS are derived using a radiative transfer model to show the potential bias features between the observations of the two instruments. The model simulation shows that for about half of the channels the biases can be in the order of 1 K for certain temperature ranges. Because each spacecraft carried two sets of VTPR instrument, but only one set was turned on at a given time, differences between two sets of channel measurement are expected to exist. It is shown that the differences between two sets of VTPR instrument can range from nearly zero for some channels to about 2 K for other channels. To make the VTPR dataset accessible to the general scientific research community, we have processed the whole VTPR data to common formats and placed the data online along with data quality statistics.
KEYWORDS: Data centers, Earth sciences, Data modeling, Information technology, Climatology, Binary data, Calibration, Satellites, Data storage, Visualization
NASA, NOAA, and USGS collections of Earth science data are large, federated, and have active user
communities and collections. Our experience raises five categories of issues for long-term archival:
*Organization of the data in the collections is not well-described by text-based categorization
principles
*Metadata organization for these data is not well-described by Dublin Core and needs attention to data
access and data use patterns
*Long-term archival requires risk management approaches to dealing with the unique threats to
knowledge preservation specific to digital information
*Long-term archival requires careful attention to archival cost management
*Professional data stewards for these collections may require special training.
This paper suggests three mechanisms for improving the quality of long-term archival:
*Using a maturity model to assess the readiness of data for accession, for preservation, and for future
data usefulness
*Developing a risk management strategy for systematically dealing with threats of data loss
*Developing a life-cycle cost model for continuously evolving the collections and the data centers that
house them.
In anticipation of the large jump in data volumes projected from future operational satellite and weather radar systems, and as lead agency for climate science, NOAA is developing ambitions programs for data and information stewardship. These programs are intended to provide broad access to a suite of products and services and to ensure long-term preservation of not simply the data, but of the information content of the observations. This paper outlines the vision and scope of these programs.
Cloud cover information and the frequency of upper tropospheric clouds have been extracted from NOAA/HIRS polar orbiting satellite data from 1979 to 2001. The HIRS/2 sensor was flown on nine satellites from TIROS-N through NOAA 14 during this time forming a consistent 22-year record. CO2 slicing was used to infer cloud amount and height. Trends in cloud cover and high cloud frequency are small in these data. High clouds show small but statistically significant increasing trends in the tropics and northern hemisphere. The HIRS analysis contrasts with that from the ISCCP which shows decreasing trends in both total cloud cover and high clouds during most of this period. The HIRS detection of upper tropospheric thin cirrus creates most of the difference with respect to ISCCP; GLAS observations of high thin clouds are largely in agreement with the HIRS.
Seasonal changes in global cloud cover have been monitored with multi-spectral observations from the eleven polar orbiting HIRS (High resolution Infrared Radiation Sounder) since December 1978. The HIRS longwave infrared data have a higher sensitivity to semi-transparent cirrus clouds than visible and infrared window techniques. Clouds are found in 71% of all HIRS observations from 65 S to 65 N; high clouds are observed in 33% of the observations. Closer investigation of the tropics indicates that there has been little overall change in the global total cloud cover. There is the possibility of a small increase in high cloud cover from the first decade to the second (about 1%) however orbit drift of some sensors and instrument differences may be part of this. Significant weather events such as El Nino Southern Oscillation or volcanic eruptions may also be influencing the trends. Since 2000, the Moderate resolution Imaging Spectro-radiometer (MODIS) is starting to generate another cloud data set that must be understood and connected with the HIRS cloud data; early indications are promising that MODIS will be a more than worthy successor to the venerable HIRS.
A combined active-passive remote sensing system has been developed to study atmospheric radiation and cirrus cloud radiative properties at the NOAA Mauna Loa Observatory on the island of Hawaii. The active portion of this system is an eye-safe, dual-polarization lidar, while the passive portion is a Fourier transform spectro-radiometer operating in emission mode. The combined system allows unattended, remote measurements of infrared atmospheric emission and clouds with depolarization discrimination of ice and liquid.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.