Sensors which collect information for intelligence, surveillance and reconnaissance generate a substantial amount of data. High data rates are required to transmit the information in reasonable time intervals. This paper describes the objectives and progress on the development of laser communication terminals for aircraft, transmitting high speed data over distances greater than 100 kilometers. The terminals are being designed and built under the Air Force Research Laboratory's EO Sensor Technology & Evaluation Research (ESTER) program.The free space laser communication system consists of three terminals developed around commercial fiberoptic standards. They are designed to be an open system, full duplex, protocol neutral, and operate at 2.5 gigabit per second, capable of expanding to 10 gigabit per second. The terminal's data rate can be reduced if atmospheric effects cause a significant increase in bit error rate. The free space optics are mounted in a pointing & tracking gimbal which interfaces with an avionics unit that measures aircraft GPS information. Fine pointing and tracking is maintained by using a beacon signal which switches from wide to narrow divergence when signal lock is achieved. The terminals are designed to operate in air-to-ground and air-toair scenarios. Subsystem laboratory tests are being completed and the terminals are being prototyped. The first set of tests will be conducted between ground sites and the first flight demonstration will involve interfacing with the multi-purpose common data link (MP-CDL) on an aircraft.We provide a description of our terminal design, show our estimated operational performance, describe the results of laboratory testing, and outline the future program activities. OVERVIEWThe development of using modulated lasers to transmit data at high rates was conceived and attempted for many decades prior to the 2000s. The benefits are obvious with long range transmission at modest power levels compared to RF thanks to the spectral coherence of the laser sources. Also, the wavelengths of the lasers allow for terahertz bandwidths and are only limited by the current state of the electro-optic components. However, many challenges were also realized from the first experiments including the impact of atmospheric turbulence, cloud obscurations, tight angular pointing and tracking, and component ruggedness.An Air Force Research Laboratory (AFRL) Sensors Directorate program was initiated in 2003 to utilize the latest in electro-optic technology and apply them in the generation of laser communication terminals for use on airborne platforms. While previous projects focused on demonstrating or advancing the state-of-the-art of many of the key approaches needed for airborne lasercom, this program is developing operational prototypes that pass real data from networks located within the aircraft and transfer this data to a secondary network located on another aircraft or ground site.

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This work surveys the properties of materials at 1.3 pm. The interest in this wavelength has been generated by the development of second generation optical fibers and by the development of the iodine (1 *) laser, which operates at 1.315 pm. Most of the data reported here were taken by Nd:YAG lasers modified to operate at 1.319 pm. Spectral scans of some less common materials are presented. The effective optical absorption coefficient ßeff measured by laser rate calorimetry is given for all materials. The thermo -optic coefficient ôn /aT at 1.3 pm is given for a number of materials. If 1.3 pm results are lacking, values at 1.15 pm are given. Among the lower absorbing materials are KCI, LiF, NaCI, CaF2, Si02, YLF (LiYF4), sapphire (A1203), MgF2, BaF2, and Q -98 phosphate glass. Results on a number of Schott infrared and laser glasses are given, including LG -680, IRG -7, IRG -9, IRG -3, and IRG -N6. Results are given also on ZnS (normal and water clear), YAG (Y3A15012), Zr02, SrF2, ZnSe, MgO, and CdTe. Some other glasses studied were hafnium fluoride glass, As2S3, CORTRAN 9753 and 9754, and Barr & Stroud calcium aluminate glasses BS 39B and BS 37A. The ten lowest absorbing materials had effective optical absorption coefficients ßeff between 0.13 and 0.5 X 10 -3 cm -1. The lowest ô n/aT value measured was -0.06X10 -5 / °C on Schott LG -660 alkali -Zn-silicate glass.

The NASA Physical Oceanographic Distributed Active Archive Center (PO.DAAC) at Jet Propulsion Laboratory is funded by the NASA Earth Science Data and Information System (ESDIS) project to conduct a study of cloud services for data management, data access and data processing. The study is to improve our understanding and articulate the cost/benefit of cloud technologies for the NASA Distributed Active Archive Centers (DAACs) and Science Investigatorled Production Systems (SIPs). This demonstration focuses on our experience in developing climatology services using Apache Hadoop to store and analyze temporal and spatial characteristics of scatterometer data over Antarctica.