Laser Technique Assessment in GIS Data Acquisition Technical Assessment For POEC 6383 Tianyou Chen Rui Ge 3/12/2014
Tasks Acquire Laser mapping equipment for GIS spatial data acquisition: • Utility mapping (power poles, water valve, gas pipe, water pipe, etc) • Construction (ask for higher accuracy) • Digital geology mapping (geologic features)
Laser Mapping – Why It is Needed • Laser + GPS = fast 3D spatial data acquisition • Mapping the inaccessible area • More efficient and cost effective
Technical Basics • Distance measure + Angle (H & V) measure • Using NIR / Red Laser (Light Amplification by Stimulated Emission of Radiation) pulse for distance measure • Using magnetic compass or encoder for angle measurement Emitter Receiver Target Distance Laser Instrument Distance = C x T / 2 C – speed of light T – time
Accuracy Distance Angle (horizontal & vertical) Function Support Reflectorless Motorized Autotrack (high-caliber) Continuous mode Remote control (high-caliber) Technical Assessment Standards • Performance • Measurement Time • Measurement Range • Ease of use • GPS integration • External interface • Display • Laser Plummet (high-caliber) • Cost
Technology Assessment Focus • Low Caliber (lower accuracy) • Advantage Laser Range Finder from Laser Atlanta • LaserAce / ALS series from MDL • High Caliber (high-accuracy) • GTS-800 and GPT-2000 series from Topcon • TCRA1100 series from Leica
Analysis for low caliber equipment • Advantage is better than LaserAce in: • Range (600m) • Angle accuracy (0.01°) • HUD display • GPS integration • LaserAce is within the same price range as Advantage and a little better in distance accuracy (10 cm to 15 cm) but inferior in: • Range (300m) • Angle accuracy (0.2°) • MDL Quarryman is superior of all but: • very specialized and expensive and less portable
Suggestion for Low caliber Laser equipment For general purpose laser mapping, choose Advantage because of the above superiorities over LaserAce within a reasonable price
Analysis • GTS800 series is superior in accuracy and in other aspects but: • Do not support reflectorless • Expensive • GPT2000 series • Supports reflectorless mode • Quick measuring time and • Reflectorless tracking mode • Cheaper • Leica TCRA1100 series • All in one with • Very expensive
Suggestions • GPT2003 will be a good choice for doing high accuracy general purpose mapping because of its support for both prism and non-prism mode with a reasonable price
Conclusions • For low accuracy, Advantage laser range finder from Laser Atlanta is a choice for its better performance (600m range) and higher accuracy(0.01°) • For high accuracy, Topcon GTP2003 is selected for its support for reflectorless mode and tracking mode, and cheaper price
References • http://www.laseratlanta.com • http://www.mdl.co.uk • http://www.topcon.com • http://www.leica.com End
Laser Atlanta Optics, Inc., Norcross, GA USA, has been designing and manufacturing eye-safe laser-based distance and speed measuring systems since 1989. Currently manufacture a product line based on a core technology called the Advantage. All of its rangefinder products are based on this proven design. Company Briefs Measurement Devices Ltd. (MDL) is a leading designer, manufacturer and supplier of laser measurement systems. MDL is committed to preserving a quality system throughout all levels of our business, as well as providing consistent, high standards of customer service.
Topcon America Corporation (TAC), based in Paramus, NJ, is the wholly-owned American subsidiary of Topcon Corporation, the world’s leading manufacturer of surveying, ophthalmic, GPS and industrial instruments and positioning control products for the civil engineering and construction industries. Company Briefs (cont.) Leica Geosystems is a globally active surveying and geomatics technology group. It provides modern systems for high-accurate 3D data capturing, visualisation and modelling of space-related data. Headquarters are in Heerbrugg, Switzerland, with further research, development and production facilities are located in Unterentfelden, Switzerland, in America (Atlanta, Grand Rapids, Oakland, San Diego, Torrance) and in Asia (Singapore).
Advantage From Laser Atlanta • Physicals • 905 nm class I eye safe laser • 11.5Hx21.5Wx19Lcm • 4.5 lbs(2.1kg) • Handle batteries
LaserAce From MDL • Physical • GaAs Laser Diode 905nm • Class I eye Safe • 175x106x55 mm (LxWxH) • 600g • Alignment Telescope: red dot • Compass(option) • Pocket PC (option) • Physical • Semi-conductor 905 nm • Class I eye safe • 209 x 243 x 420mm (LxWxH) • 9.7kg /10.3 kg (w/ tribrach) • Optical encoder • Laptop/palm/desk top PC
Topcon: Pulse Total Station GPT-2000 series • Using pulse laser technology • Support both prism/non-prism mode • High accuracy: • Millimeter accuracy in distance measurement (5mm+2ppm xD in non prism mode; 3mm+2ppmxD in prism mode) • 1”/ 5” (H & V) angle measurement accuracy • Fast data acquisition: • 0.3 sec tacking mode • 1.2 second fine mode • Long range: • Prism: 7,000m • Non prism: 150m • All weather operation: water /dust proof • Large data storage: 8000 points • Laser plummet
Total Station GTS-800/800A seriesfrom Topcon • Motorized & automatic tracking – high speed rotation (up to 50º /sec) and high speed auto-tracking (up to 5º /sec) • Remote control through radio link or optical remote controller – enables one man operation • Flexible data management: Huge data storage – 2Mb memory plus PCMCIA card, space for data and software • User friendly • Large graphic display • Built-in MS-DOS OS • Compact and light weight • Water / dust resistant • Handheld data collector • TDS Survey Pro software allows more functions: job classification, stake out, etc.
Leica TCRA1100 series Total Station • Motorized, automatic target recognition, reflectorless and remote control • Accuracy: • Angle measurement: from 1.5” to 5” • Distance measurement: 3mm+2ppm w/o reflector; 2mm+2ppm w/ reflector • Range: 200m (w/o reflector) to 7.5 km (w/reflector) • Time • 1sec w/ reflector • 3 sec w/o reflector • Data storage: PCMCIA card or export via RS232 • Software supports: • computations of area, height, tie distance etc. • stake outs • Exchange data between instrument and PC • Create code list
Range-Reflector 3 km (circular prism) 1.5 km (360 degree prism) Reflectorless - standard range 80m (without reflector) 5 km (circular prism) Reflectorless - eXtended Range 200m (without reflector) 7.5 km (circular prism) Leica TCRA1100 series Range
External Interface The external interface provides a way for the instrument to communicate with a PC, a laptop, a palm or a data logger. All the models here have this ability