The use of ALS, TLS and VLS measurements in mapping and monitoring urban trees

We evaluated an accuracy and efficiency of laser measurement methods that can be utilized in urban tree mapping and monitoring. In this paper we describe our methods and show the first results of the study. In the field, altogether 44 urban trees located in park environment were measured and mapped from our pilot area located in Seurasaari, Helsinki, Finland. Several laser scanning methods were compared and tested beside direct GPS measurements. These methods included airborne, terrestrial and vehicle-based laser scanning. Tree mapping was done straight from the point clouds. The most cost-efficient method to produce tree maps from the scratch would be ALS combined with field measurements. Our first results showed also great potential of vehicle based laser scanning to be used in updating of existing tree maps and monitoring urban forest environment. The mapping accuracy was in line with traditionally used tachymeter measurements. All of these laser-based measurements were more cost-efficient than tachymeter measurements.