Category Archives: Lidar sensor

The following is a good representation of corn rows in LiDAR data. Corn rows appear for a number of reasons and can be seen in a single scan or in overlapped areas of two adjoining scans. The corn rows in a single scan can be caused by the back and forth scanning of the system. The manufactures say that any given point needs to be within a certain distance of the actual location on the ground. Well this means that that point measurement can be below the actual elevation on the ground or above the actual elevation of the ground. This makes the distance between the points greater creating the appearance of corn rows. Since the error of a LiDAR sensor is greatest at the edge of scan these corn rows are most apparent at the edges of scans. The presents of corns rows is compounded when you have overlapping flight lines because of the inherent error of the scanner or measurement of any given point, the back and forth scan pattern and difference between the elevation measurements between the two scans. This differences will usually be a result of bad calibration. A lot of processing techniques have been developed to remove corn rows but almost always you can see some existences of corn rows in raw LiDAR ( unclassified strips ). The manufactures of LiDAR systems have improved on this issue and continue to make their systems better. The only time I have seen no existence of corn rows is from a system that generates scans in a single direction but I am confident that at some point the technology will improve to the point that we don’t have to talk about corn rows as a result of system function. If you have any insight on the latest systems or systems that address this issue effectively please let me know or leave a comment.

Hexagon Geosystems Geospatial Division is proud to announce the release of the ALS70, our latest airborne LiDAR system. There are many new innovations in the ALS70 and we wanted to share this news with you.
Leica Geosystems announces the release of the new ALS70 family of airborne LiDAR systems. The new product line, consisting of ALS70-CM City Mapper, ALS70-HP High Performance and ALS70-HA High Altitude models, covers the entire range of LiDAR mapping applications, and represents a significant advancement in the state-of-the-art for airborne LiDAR.

Industry-Leading 500 KHz Pulse Rate
According to Ron Roth, Product Manager for Airborne LiDAR at Hexagon Geosystems’ Geospatial Solutions Division, “The market constantly demands higher productivity from airborne sensing systems to reduce the equipment and labor costs associated with data collection, but this cannot be done at the expense of data quality. By incorporating Point Density Multiplier technology, we were able to develop a LiDAR product that offers an industry-leading 500 kHz pulse rate and 200 Hz scan rate, for ultra high point density and unrivaled control over the point pattern on the ground. This new technology gives the superior data acquisition productivity that our customers desire, without the complexity of multiple lasers or scanners.”

New Detection Circuitry
“In addition to Point Density Multiplier, ALS70 incorporates new detection circuitry providing superior sensitivity to small or low-reflectivity targets. This has proven itself already on power line data acquisition, where even the smallest high-voltage and ground wires can be readily measured” explains Ron Roth.

Upgradeability of Existing Leica ALS60 Systems
“Market acceptance has been extremely encouraging, with 8 systems, representing the entire product line, delivered already. Because this technology is based on the proven Leica ALS60 platform, existing ALS60 systems can be transformed into the new model, thus preserving current customers’ investments” concludes Ron Roth.