Probabilistic analysis of linear mode vs. geiger mode APD FPAs for advanced LADAR enabled interceptors

2006 ◽  
Author(s):  
George M. Williams ◽  
Andrew S. Huntington
Keyword(s):  
Probabilistic Analysis ◽  
Linear Mode ◽  
Geiger Mode

scholarly journals A Comparative Study between Frequency-Modulated Continous Wave LADAR and Linear LiDAR

2014 ◽  
Vol XL-1 ◽  
pp. 233-239 ◽  
Author(s):  
R. D. Massaro ◽  
J. E. Anderson ◽  
J. D. Nelson ◽  
J. D. Edwards
Keyword(s):  
Continuous Wave ◽  
Single Frequency ◽  
Range Resolution ◽  
Linear Mode ◽  
Radar Systems ◽  
Flash Lidar ◽  
Geiger Mode ◽  
The Difference ◽  
Set Up ◽  
The Given

Topographic Light Detection and Ranging (LiDAR) technology has advanced greatly in the past decade. Pulse repetition rates of terrestrial and airborne systems havemultiplied thus vastly increasing data acquisition rates. Geiger-mode and FLASH LiDAR have also become far more mature technologies. However, a new and relatively unknown technology is maturing rapidly: Frequency-Modulated Continuous Wave Laser Detection and Ranging (FMCW-LADAR). Possessing attributes more akin to modern radar systems, FMCWLADAR has the ability to more finely resolve objects separated by very small ranges. For tactical military applications (as described here), this can be a real advantage over single frequency, direct-detect systems. In fact, FMCW-LADAR can range resolve objects at 10<sup>−7</sup> to 10<sup>−6</sup> meter scales. FMCW-LADAR can also detect objects at greater range with less power. In this study, a FMCWLADAR instrument and traditional LiDAR instrument are compared. The co-located terrestrial scanning instruments were set up to perform simultaneous 3-D measurements of the given scene. Several targets were placed in the scene to expose the difference in the range resolution capabilities of the two instruments. The scans were performed at or nearly the same horizontal and vertical angular resolutions. It is demonstrated that the FMCW-LADAR surpasses the perfomance of the linear mode LiDAR scanner in terms of range resolution. Some results showing the maximum range acquisition are discussed but this was not studied in detail as the scanners’ laser powers differed by a small amount. Applications and implications of this technology are also discussed.

scholarly journals Evaluation of SPL100 Single Photon Lidar Data

2020 ◽  
Vol 12 (4) ◽  
pp. 722 ◽  
Author(s):  
Rebecca Brown ◽  
Preston Hartzell ◽  
Craig Glennie
Keyword(s):  
Point Cloud ◽  
Single Photon ◽  
Collection Efficiency ◽  
Incidence Angle ◽  
New Technology ◽  
Linear Mode ◽  
Digital Elevation ◽  
Commercial Market ◽  
Geiger Mode ◽  
Elevation Model

Geiger-mode and single photon lidar sensors have recently emerged on the commercial market, advertising greater collection efficiency than the traditional linear mode lidar (LML) systems. Non-linear photon detection is a new technology for the geospatial community, and its performance characteristics for surveying and mapping are not yet well understood. Therefore, the geospatial quality of the data produced by one of these new sensors, the Leica SPL100, is examined by comparing the achieved lidar point cloud accuracy, precision, digital elevation model (DEM) generation, canopy penetration, and multiple return generation to a LML point cloud. We find the SPL100 has a lower ranging precision than linear mode lidar and that the precision is more negatively affected by surface properties such as low intensity and high incidence angle. The accuracy of the SPL100 point cloud, however, was found to be comparable to LML for smooth horizontal surfaces. A 1 m resolution SPL100 DEM was also comparable to a corresponding LML DEM, but the SPL100 was observed to have a reduced ability to resolve multiple returns through vegetation when compared to a LML sensor. In its current state, the SPL100 is likely best suited for applications in which the need for collection efficiency outweighs the need for maximum precision and canopy penetration and modeling.

SOLAR-BLIND SINGLE-PHOTON 4H-SiC AVALANCHE PHOTODIODES

2009 ◽  
Vol 19 (01) ◽  
pp. 85-92
Author(s):  
ALEXEY VERT ◽  
STANSILAV SOLOVIEV ◽  
JODY FRONHEISER ◽  
PETER SANDVIK
Keyword(s):  
Detection Efficiency ◽  
Single Photon ◽  
Optical Filter ◽  
Single Photon Detection ◽  
Dark Count ◽  
Photon Detection ◽  
Linear Mode ◽  
Solar Blind ◽  
Geiger Mode ◽  
Photon Detection Efficiency

A solar blind 4 H - SiC single photon avalanche diode (SPAD) is reported. The SPAD with separate absorption and multiplication layers was designed for operation with low dark counts. A thin film optical filter deposited on a sapphire window of the device package provided sensitivity in the wavelength range between 240 and 280 nm with a very high solar photon rejection ratio. An estimated dark current of 0.4 pA (0.75 nA/cm2) at a gain of 1000 was measured on a device with an effective mesa diameter of 260 µm. A single photon detection efficiency of 9% (linear mode) and 9.5% (gated Geiger mode) were achieved at a wavelength of 266 nm for the same device. Corresponding dark count rate and dark count probability were 600 Hz and 4×10-4.

FPGA-Based TDC for Single-Photon Intensity Interferometry

2016 ◽  
Vol 05 (04) ◽  
pp. 1641016 ◽  
Author(s):  
Adrian Sinclair ◽  
Genady Pilyavsky ◽  
Edward Schroeder ◽  
Philip Mauskopf
Keyword(s):  
Single Photon ◽  
Photon Detectors ◽  
Linear Mode ◽  
Avalanche Diodes ◽  
Photon Intensity ◽  
Single Photon Detectors ◽  
Field Programmable ◽  
Geiger Mode ◽  
Future Work ◽  
Intensity Interferometer

A prototype intensity interferometer readout for single-photon detectors is presented as a time-to-digital converter (TDC) implemented on a field-programmable gate array (FPGA). We briefly discuss the history and scientific motivations for the instrument. A comparison is drawn between the use of photomultiplier tubes in linear mode and single-photon avalanche diodes (SPAD) in Geiger mode. Different FPGA-based TDC configurations are discussed. We describe the design and implementation of a four-phase FPGA-based TDC. The paper concludes with the application of the design to investigate SPAD after-pulsing and a description of future work.

About definition of the local entropy rate of production in experiment of pulse electric heating

2020 ◽  
pp. 29-34
Author(s):  
Alexandr V. Kostanovskiy ◽  
Margarita E. Kostanovskaya
Keyword(s):  
Thermal Diffusivity ◽  
Electric Heating ◽  
Thermal Capacity ◽  
Entropy Rate ◽  
Initial Time ◽  
Local Entropy ◽  
Linear Mode ◽  
Electric Capacity ◽  
Definition Of ◽  
Pulse Electric

Work is devoted to studying of a linear mode thermodynamic – a mode which is actively investigated now. One of the main concepts of a linear mode – local entropy rate of production. The purpose of given article consists in expansion of a circle of problems for which it is possible to calculate a local entropy rate of production, namely its definition, using the experimental “time-temperature” curves of heating/cooling. “Time-temperature” curves heating or cooling are widely used in non-stationary thermophysical experiments at studying properties of substances and materials: phase transitions of the first and second sort, a thermal capacity, thermal diffusivity. The quantitative substantiation of the formula for calculation of the local entropy rate of production in which it is used thermogram (change of temperature from time) which is received by a method of pulse electric heating is resulted. Initial time dependences of electric capacity and temperature are measured on the sample of niobium in a microsecond range simultaneously. Conformity of two dependences of the local entropy rate of production from time is shown: one is calculated under the known formula in which the brought electric capacity is used; another is calculated, using the thermogram.

CALCULATION PARAMETERS OF SPRINKLING MACHINES WITH COMBINED FRONTAL AND CIRCULAR MOVEMENT

1970 ◽  
pp. 4-7
Author(s):  
N. N. Dubenok ◽  
G. V. Olgarenko ◽  
B. S. Gordon
Keyword(s):  
Calculated Data ◽  
Irrigation Scheduling ◽  
Natural Conditions ◽  
Linear Mode ◽  
Irrigation Technology ◽  
Irrigated Area ◽  
Center Pivot ◽  
Irrigation Technologies ◽  
The Given ◽  
Operation Characteristics

If the center pivot or linear moving irrigation machines are operated with their own individual irrigation technologies, but the irrigation machines with combined center-pivot and linear moving mode are operated on one field in turn as a center pivot and as a linear. The goal of this work is creation of theoretical base for calculation of improved irrigation machines parameters and existing irrigation equipment modernizing, according to the different natural conditions. The research object is investigation of characteristics of rain delivered from irrigation machines with combined center-pivot and linear moving mode, assuring uniform irrigation distribution according to the irrigation technology and operation parameters, size and configuration of seasonal norm as well as to the irrigation scheduling. The pointed goal is achieved by the given problem solving, when having basic data on the irrigation norm and time, as well as operation characteristics and the irrigation area configuration, the predicted hydro modulus are calculated for the irrigation machine working in a center pivot and in a linear mode. The simulation of sprinkling devices operation on the machine is made by one universal formula, when on the plots irrigated in center pivot and linear mode is achieved equality of arranged hydro modulus to the corresponding calculated data. At that, are considered all the possible combinations of the total irrigated area parts, irrigated with different technologies.

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