The Altus Cumulus Electrification Study (ACES) was a field investigation that focused on studying electrical activity within storms and validating satellite observations from the Lightning Imaging Sensor (LIS). ACES consisted of one deployment in August 2002 over the Florida Everglades. An uncrewed aerial vehicle (UAV), ALTUS II, was used to collect measurements of the electric field and lightning of thunderstorms. Ground-based measurements from various lightning detection networks were also collected. ACES supported NASA's TRMM mission and the UAV Science Demonstration Program.
Rain gauges are ground-based instruments that provide in situ measurements of liquid precipitation amounts over a set time. There are multiple types of rain gauges that each collect and record data differently such as the tipping bucket rain gauge and weighing precipitation gauge. Rain gauges can be deployed in various locations due to their relatively small size and easy set-up and are typically colocated with other precipitation instruments such as disdrometers to provide more details about precipitation being collected such as precipitation rate and size distribution.
The Radio Acoustic Sounding System (RASS) is an active ground-based acoustic sounder that provides profiles of virtual temperature. It uses radar techniques to measure acoustic disturbances to derive the virtual temperature. They are typically used in conjunction with radar wind profilers (RWPs) and operate at frequencies of 915 MHz and 1290 MHz. RASS has a sampling rate of around 5 to 15 minutes, a 150 m vertical resolution, and a 60 m horizontal resolution.
Earth Science > Atmosphere > Atmospheric Temperature > Surface Temperature > Boundary Layer Temperature
A Four beam system that uses Yagi antenna with enhanced beam steering capability and contains a Median Filter First Guess (MFFG) algorithm to generate a wind profile from Doppler spectra at each range gate
A commercial lightning detection network operated by Vaisala. A network of antennae are connected to a central processor that records the time, polarity, signal strength, and number of strokes of each cloud-to-ground lightning flash detected over the United States.
The Cloud‐to‐Ground Lightning Surveillance System (CGLSS) located at the Kennedy Space Center consists of six medium-gain IMPACT Enhanced Sensitivity and Performance (ESP) sensors developed by Vaisala. The CGLSS network processes cloud-to-ground lightning signals by detecting an electromagnetic waveform of the return stroke, transmitting that data to a central processor that estimates stroke intensity and location, and sending the information to users in a real-time setting. Lightning occurrences from the network are used for decision support towards ground and launch activity on the Florida coast.
The Lightning Detection and Ranging (LDAR) instrumentation network is a volumetric lightning mapping system located at the Kennedy Space Center; with a center location at 28.54N and 80.64W. The LDAR system provided near-real time support of lightning occurrence and location for the Space Shuttle missions. The seven antennas that comprise the LDAR network allow detection of 99% of all intra-cloud and cloud to ground flashes that occur within 10 kilometers of the instrumentation. Each antenna detects the 66 Megahertz Very High Frequency (VHF) pulse from an intra-cloud flash and an electric field detector detects cloud to ground flashes by measuring changes to the electric field from the flash. The root mean square error of the location of each of the detected flashes varies between 100 meters from within the network to approximately 10 kilometers within 90 kilometers outside the network. Data from the LDAR system are currently provided by the Global Hydrology Resource Center.
Earth Science > Atmosphere > Atmospheric Electricity > Electric Field
The Next Generation Weather Radar (NEXRAD) is a network of high-resolution, S-band radars operated by the National Weather Service (NWS), the Federal Aviation Administration (FAA), and the United States Air Force. NEXRAD measures the magnitude of the returned energy to provide reflectivity, velocity, and spectrum width observations, which can be processed to create mosaic maps of precipitation. NEXRAD radars typically operate with a 0.9 degree beamwidth, 0.25-1 km spatial resolution, and 230-460 km maximum range. There are currently over 160 NEXRAD radars operating in the United States and select overseas locations.
The Dual Optical Pulse Sensor (DOPS) is an airborne optical sensor used to study lightning in the atmosphere. It is an updated version of the Optical Pulse Sensor (OPS). DOPS collects measurements of lightning's duration, intensity, and waveform characteristics. It operates across two channels centered at 500 and 777.4 nm and has a sample duration of 0.328 seconds. It has a wide field of view (60 degrees) and can detect lightning during daytime conditions.
The Fluxgate Magnetometer (FGM) is a type of instrument that takes measurements of the magnetic field. There are multiple types of FGMs. FGMs operated on airborne platforms can be used to measure changes in the ambient magnetic field during flights.
The Electric Field Change Meter is an instrument that detects changes in the electric field that occur after lightning flashes. It has been used as both a field instrument and an airborne instrument. It has a high temporal resolution, making it useful for taking measurements before, during, and after lightning flashes.
Earth Science > Atmosphere > Atmospheric Electricity > Electric Field
The Gerdien Conductivity Probe was designed to measure the atmospheric electrical conductivity. In order to determine the conductivity, a sample of air is exposed to a capacitor and the time taken to discharge is measured. The Gerdien Probe can detect both the positive and negative ion conductivity. The conductivity of ions is determined by supplying a voltage between two electrodes over a period of one minute and measuring the resulting current. The rate of change of the current with respect to voltage provides a measure of conductivity. Additionally, special considerations were taken in construction to reduce the influence of electromagnetic interference and current leakage.
The magnetic search coil measures dB/dt, or temporal changes in magnetic flux density, which couples to the instrument in two distinct ways. The intended mechanism is transformer coupling, whereby alternating current (AC) field lines from a distant source couple to the windings of the sensor. The secondary mechanism is generator coupling, whereby the sensor is physically displaced within a direct current (DC) magnetic field.
An Electric Field Mill (EFM) is an in situ airborne and ground-based electric sensor designed and built at NASA Marshall Space Flight Center (MSFC). It measures the full vector components of the atmospheric electric field and provides details about the electrical structure within and around a storm. EFMs can detect both intracloud and cloud-to-ground lightning and can operate during large thunderstorm fields (thousands of volts/meter). An EFM has a typical time response of about 10 Hz.
Earth Science > Atmosphere > Atmospheric Electricity > Electric Field
