MULTI-CHANNEL SCALER CARDS IMPROVE DATA COLLECTION
- Wednesday, 11 July 2007
Scientists interested in exploring the intricacies and dynamics of Earth's climate and ecosystems continually need smaller, lighter instrumentation that can be placed onboard various sensing platforms, such as Unmanned Aerial Vehicles (UAVs). Responding to a need for improved data collection for remote atmospheric measurement systems, ASRC Aerospace Corporation , of Greenbelt, Maryland, developed a series of low-power, highly integrated, multi-channel scaler (MCS) cards. The cards were designed to meet the needs of NASA's ground-based and airborne Light Detection and Ranging (LIDAR) photon-counting programs. They can rapidly collect thousands of data points during a continuous scan of the atmosphere.
ASRC Aerospace's 4-input AMCS-USB and 8-input AMCS-USB+ cards provide a multi-channel scaler capability with a USB 1.1 interface. As systems began to use these cards, ASRC Aerospace discovered that many LIDAR systems often require the MCS function along with an analog-to-digital converter for housekeeping, serial communication ports, hard drive storage, time-tagging, and quicklook data capability. As a result, the company designed the APCS card, which serves as a complete data â€œsystemâ€ on a single card. The APCS card includes all of these functions, along with a fast USB 2.0 interface and 10 MCS detector input channels. The serial ports allow for real-time quicklook data monitoring and navigational data capture, while the generic interface allows for a small laptop hard drive or rugged solid-state drive to be connected directly to the card. In addition, the company designed the APCS card with a daughtercard interface to create a very versatile system capable of high resolution. The APCS card is suited to both remotely deployed systems, such as in the UAV platform, as well as to laptop-based systems, where data can be readily monitored and controlled.
ASRC Aerospace also created a WindowsÂ®-based, graphical user interface (GUI) for the MCS cards that streamlines user interaction with the product. The GUI allows the user to write and read the MCS parameters, start acquisition with real-time, back-to-back integration and collection cycles, and log data to a text file for later review.
The AMCS-USB, AMCS-USB+, and APCS cards can be used in a variety of applications. The cards are highly integrated, in that all storage memory and multi-channel scaler functions are contained within a single chip on the cards. They can be adapted in the field, which allows the user to tailor the processor to suit the individual needs of the project. Parameters such as time resolution per bin, number of bins, accumulation delay, number of accumulations, and pulse polarity are set by the user through software control. The MCS cards transmit data to a host computer at the end of a completed integration cycle for processing and storage. All data transfers, such as commands from the host and acquired data from the card, are made through the USB interface. The cards can be used in any personal computer-based system, laptop, or desktop that has a USB port. In addition, the APCS card can store all of the collected data directly to an attached hard drive without the need for a host computer. This data can be read back at a later time with the use of a computer via the USB 2.0 interface.
Since the cards allow for many of their parameters to be configured via software, these products are attractive to industry, university, and government customers. The cards have been sold worldwide for use in advanced, high repetition-rate LIDAR systems. They can be used in environmental monitoring data systems that study everything from clouds to aerosols to pollution. The military could adapt the MCS cards for its smoke and chemical plume detection systems. The cards could also be used in non-LIDAR applications such as those for nuclear waste detection monitoring. Currently, the following LIDAR programs at NASA Goddard are benefiting from the MCS cards: Cloud Physics LIDAR, Thickness From Off Beam Returns LIDAR, Goddard LIDAR Observatory for Winds, 24-Channel Doppler LIDAR, Advanced Micropulse LIDAR, the Holographic Airborne Rotating LIDAR Instrument Experiment, and the Carbon Dioxide Detection Testbed.