|Unmanned aircraft altimeters||- Altimeters|
Ultrasonic altimeters ate placed at the wing tips and at the tail, all pointing downwards. These close proximity altemers are used in automated take off and landing phases to enable the flight control unit to accurately and quickly monitor the attitude of the UAV during take off and landing.
Our experience: we placed an order for two parts (shown above) in August 2007, and the service was both very swift and most professional.
TDC chip features 10 ps resolution
Aug 24, 2006 10:28 AM
The TDC-GPX chip, developed by Acam-Messelectronic and available in North America through Transducers Direct has a resolution as low as 10 ps and a measurement range up to 40 µsec. The new time-to-digital converter is intended for navigation systems, missile defense systems, range finders and speed measurement devices, frequency and phase measurement instruments, and medical imaging scanners.
Operating in M-mode, the GPX's 10-picosecond resolution translates to a measurement accuracy of ±1 mm rms to a range of 1500 m, with peak-to-peak variation of 70 ps (±5 mm). A peak pulse rate of 182 MHz makes the GPX chip suitable for 3-D laser scanners where a high sampling rate and excellent single-shot resolution are required.
Four selectable operating modes make the GPX suitable for a wide range of applications. In I-mode, the GPX provides eight LVTTL input channels, a resolution of 81 ps, infinite measurement range, and 5.5 ns pulse-pair resolution. G-, R- and M-modes all provide either two LVTTL or two LVPECL input channels. In G-mode, the resolution is 40 ps, the measurement range is 65 µsec, and the minimum pulse-width measurement is 1.5 ns. In R-mode, the resolution is 27 ps, the measurement range is 40 µsec, and the pulse-pair resolution is 5.5 ns. In M-mode, the resolution is 10 ps rms with a peak-to-peak of 10 ps, and the measurement range is 10 µsec. Current consumption of the GPX typically ranges from 39 mA to 45 mA.
The optional ATMD-GPX PC-based evaluation system allows design engineers to access the power of the GPX chip through a PC interface. The ATMD-GPX consists of hardware that connects to a PC and allows setting of all the relevant registers of the TDC-GPX. The PC communicates directly with the GPX chip at a data rate limited by the software and communication, and the system enables the GPX to collect data at a peak rate of 200 MHz. Measurement data can be displayed directly or as a histogram, as well as exported.
Application: laser rangefinder
Whether in geodesics, in security systems, production controls or just on the golf corse - the measuring of distances with lasers or laserscanners is well established nowadays. The time - namely the time, the light needs to pass the needed distance - is the value to be determined. This sounds so simple, but it isn't - because the velocity of light is very, very high - it's 2.99792*10 8 m/s. In consequence one has to deal with very small times. In only one microsecond the passes 300 meters. A high resolution in place therefore demands highest resolution in time.
The perfect task for a Time-to-DigitalConverter like TDC-GP1 and TDC-GPX !
Pratically the reflection mode is used. Tranceiver and receiver are placed in one device. For the distance to be measured we find d=c*t/2 with c=velocity of light. So if we take a distance of 1 kilometer, the time of flight will be 6.7us. If the resolution has to 1cm we already need a time resolution of 67ps. TDC-GPX driven in M-Mode shows a peak-to-peak resolution very close to this. The resolution can be further improved by averaging without seeing any systematic errors from the TDC.
Have a look at our Application Note AN001_e.pdf (129 KB Nov 2000).
Here the advantages, the TDC brings to you:
Photograph kindly supplied by Mark Frischman at Multiwave Sensors Inc.
Photograph kindly supplied by Mark Frischman at Multiwave Sensors Inc.
Thanks to Mark Frishman of Multiwave Sensors Inc for bringing this product to our attention.
Product number: 9001
OEM Laser Module
The LaserAce® IM OEM Laser Modules are compact class 1 eye safe, rugged, multipurpose laser distance meters for integration into OEM applications. The laser distance measuring modules have been specifically designed for additional integration each giving a reflectorless range of up to 700m (2300ft), 300m (1000ft), 150m (500ft) and 35m (110ft) for the IM700, IM300, IM150 and IM35 respectively. The sensors can be integrated into a number of suitable system applications requiring, primarily distance measurement.LaserAce® IM OEM laser modules can be configured to output range, speed and height of vehicles or objects and may also be set to trigger cameras in tollbooth or law enforcement applications. The laser sensors can also be further integrated to produce vehicle profiles and scans, classify and identify them, count axles, over height detection and much more.
Kapsch TrafficCom based in Austria use the LaserAce® IM 300’s for triggering cameras in toll booths. DI R Wieden of Kapsch TrafficCom commented, " LaserAce® IM is easy to integrate and to adopt according to the given surroundings (conditions of the location). The product perfectly fits the requirements for vehicle detection and camera triggering that we have defined."
" The primary reasons we have used the LaserAce® IM, laser modules are because they can accurately detect vehicles and classify truck versus passenger car without requiring a second mounting structure (e.g. gantry) or installing something in the roadway for multi-lane free flow applications. Most other laser detector devices must be mounted pointing straight down and thus in order to trigger a camera mounted above a lane, requires a second mounting structure (one for the laser and a different one for the camera). The MDL laser eliminates the need for the second gantry and allows us to mount the trigger device right next to the camera housing." Quote from JAI Pulnix, DenmarkAlongside traffic applications the LaserAce® IM OEM laser module is used in military, security, construction and aviation markets. From a target designator, motion detector, surveying tool and altimeter, each market segment has its own special requirement. Here at MDL we are aware that no two applications are exactly the same so we work with our OEM partners to provide unique solutions to their individual applications and are always willing to help. LaserAce® IM OEM laser module is cost effective, accurate, fast and environmentally sealed to IP67 making it the most robust sensor on the market today!
The OEM laser modules use time-of-flight technology, put simply, it measures the time taken for a very short pulse of infrared laser light to travel from one window in the module, to a very low noise detector in a second window. The distance to the target is calculated from the time taken to make the round trip. The reflected light signal levels are very low, so the greater the reflectivity of a target, the longer the range over which this target can be ‘seen’. Therefore, reflective targets will increase the range of each of the LaserAce® IM OEM laser modules.We provide a set of standard systems, which are designed for easy integration in all applications based on commonly required specifications. Other variations are available and customisations can be provided for OEM integrators. Please talk to use about your applications and needs so that we can show you how our LaserAce® OEM Laser modules can help you.
MDL’s standard laser module with a repetition rate of 9Hz. This unit is used in airborne laser altimetry, distance measurement and collision avoidance.
The new Roke Manor Research MRA Type 2 altimeter, with integral antenna, from www.roke.co.uk
The above information kindly supplied by:
Dr. Donald Hardie PhD MEng (Hons)
MRA BusinessDevelopment Manager
Professional ProductEngineering Group
TEL: +44 (0)1794 83 3125
FAX: +44 (0)1794 83 3433
MOBILE: +44 (0)791 9536807