The High-resolution Imaging Multiple-species Atmospheric Profiler (HiMAP) is an ultraviolet imaging spectro-polarimeter in development at the Jet Propulsion Laboratory for measuring O3 and NO2 concentrations in the troposphere from an airborne platform or satellite. In this paper: (1) the HiMAP design is illustrated and modeled using 3D polarization ray tracing calculus, (2) the dependency between the condition number of the systems polarization measurement matrix and properties of individual optical components is used as a method for tolerancing, and (3) the polarimeter capabilities of manufacturable thin film designs of polarizing and non-polarizing beam splitters is explored using numerical methods. The condition number of an optical system is calculated from a polarization ray tracing (PRT) matrix model of the polarimeter. Deviations of the condition number are calculated for non-ideal polarization elements and coatings to understand component and alignment tolerances.
The Jet Propulsion Laboratory Carbon Dioxide Laser Absorption Spectrometer (CO2LAS) utilizes Integrated Path
Differential Absorption (IPDA) at 2.05 μm to obtain CO2 column mixing ratios weighted heavily in the boundary layer.
CO2LAS employs a coherent detection receiver and continuous-wave Th:Ho:YLF laser transmitters with output powers
around 100 milliwatts. An offset frequency-locking scheme coupled to an absolute frequency reference enables the
frequencies of the online and offline lasers to be held to within 200 kHz of desired values. We describe results from
2009 field campaigns when CO2LAS flew on the Twin Otter. We also describe spectroscopic studies aimed at
uncovering potential biases in lidar CO2 retrievals at 2.05 μm.
For more than a decade, CD-ROM and CD-R have provided an unprecedented level of reliability, low cost and cross-platform compatibility to support federal data archiving and distribution efforts. However, it should be remembered that years of effort were required to achieve the standardization that has supported the growth of the CD industry. Incompatibilities in the interpretation of the ISO-9660 standard on different operating systems had to be dealt with, and the imprecise specifications in the Orange Book Part II and Part III led to incompatibilities between CD-R media and CD-R recorders. Some of these issues were presented by the authors at Optical Data Storage ’95. The major current problem with the use of CD technology is the growing volume of digital data that needs to be stored. CD-ROM collections of hundreds of volumes and CD-R collections of several thousand volumes are becoming almost too cumbersome to be useful.
This paper describes the Data Distribution Laboratory and discusses issues involved in building multimedia CD-ROMs. It describes the modeling philosophy for cataloging multimedia products and the world-wide web-based multimedia archive and retrieval system built on that model.
CD-R media is increasingly being looked upon as an excellent archival media with an estimated storage life on the order of 100 years. Since the government will be making large investments in CD-R media, it is imperative that the characteristics of media, recorders, test devices, and compatibility with CD-ROM readers be understood. This article summarizes the results of a CD-R media evaluation conducted by SIGCAT (the Federal Special Interest Group for CD-ROM Applications and Technology) and follow-on evaluations performed by the Data Distribution Laboratory at JPL. For this evaluation, 250 media samples from various manufacturers were recorded on several recorders at different record rates. Every byte of every disc recorded in the study was retievable on some, but not all, CD-ROM readers. We are confident that any commercially available media recorded on 2X recorders will provide a reliable archival media. We have, however, identified incompatibilities between single-speed (1X) recorders and phthalocyanine-based media and between high speed recorders (i.e. 4X and 6X recorders) and cyanine-based media. We recommend that the industry address the recorder and media incompatibilities and that a specification be developed for robust CD-R reader for use in archival applications.
Conference Committee Involvement (2)
Lidar Remote Sensing for Environmental Monitoring XII
21 August 2011 | San Diego, California, United States
Lidar Remote Sensing for Environmental Monitoring XI