Cramer, J. | Search NASA

NASA NTRS2000

Status Report on the Penn State RBCC Test Program

The status of the RBCC ejector mode research program at Penn State is reviewed. Recent hardware modifications and measurement system improvements are discussed, including the motivation for these changes. Results from a series of tests with a single thruster configuration at a chamber pressure of 200 psia and with an area ratio 3.3 nozzle are presented. These results indicate that the primary (rocket exhaust) and secondary (entrained air) flow streams mix much more rapidly than a previous test series with an area ratio of 6.0 nozzle. Finally, the plans for a test series with a twin thruster configuration are discussed.

Cramer, J.↗

NASA NTRS1999

Cross-Sensor Calibration of the GAI Long Range Detection Network

The long range component of the North American Lightning Detection Network has been providing experimental data products since July 1996, offering cloud-to-ground lightning coverage throughout the Atlantic and Western Pacific oceans, as well as south to the Intertropical Convergence Zone. The network experiences a strong decrease in detection efficiency with range, which is also significantly modulated by differential propagation under day, night and terminator-crossing conditions. A climatological comparison of total lightning data observed by the Optical Transient Detector (OTD) and CG lightning observed by the long range network is conducted, with strict quality control and allowance for differential network performance before and after the activation of the Canadian Lightning Detection Network. This yields a first-order geographic estimate of long range network detection efficiency and its spatial variability. Intercomparisons are also performed over the continental US, allowing large scale estimates of the midlatitude climatological IC:CG ratio and its possible dependence on latitude.

Boccippio, Dennis J.↗