Penn State Data Commons - Full Metadata

Abstract:

High resolution land cover dataset for Montgomery County.  Seven land cover classes were mapped: (1) tree canopy, (2) grass/shrub, (3) bare earth, (4) water, (5) buildings, (6) roads, and (7) other paved surfaces.

The primary sources used to derive this land cover layer were 2009 imagery and LiDAR.  Ancillary data sources included planimetric GIS data provided. This land cover dataset is considered current as of summer 2009.
Object-based image analysis techniques (OBIA) were employed to extract land cover information using the best available remotely sensed and vector GIS datasets.  OBIA systems work by grouping pixels into meaningful objects based on their spectral and spatial properties, while taking into account boundaries imposed by existing vector datasets.  Within the OBIA environment a rule-based expert system was designed to effectively mimic the process of manual image analysis by incorporating the elements of image interpretation (color/tone, texture, pattern, location, size, and shape) into the classification process.  A series of morphological procedures were employed to insure that the end product is both accurate and cartographically pleasing.
No accuracy assessment was conducted, but the dataset was subject to a thorough manual quality control.  More than 30,000 corrections were made to the classification.

Purpose:

This dataset was developed as part of the Urban Tree Canopy (UTC) Assessment for Montgomery County. As such, it represents a "top down" mapping perspective in which tree canopy over hanging other features is assigned to the tree canopy class. At the time of its creation this dataset represents the most detailed and accurate land cover dataset for the area.

Supplemental_Information:

Funding for this project was provided by M-NCPPC, Sandia National Laboratories and the USDA Forest Service.  The methods used were developed by the University of Vermont Spatial Analysis Laboratory with funding from the USDA Forest Service.

Currentness_Reference:

ground condition

Use_Constraints:

None

Address:

81 Carrigan Drive

Address:

Aiken Room 220

Data_Set_Credit:

University of Vermont Spatial Analysis Laboratory

Attribute_Accuracy_Report:

No accuracy assessment was conducted, but the dataset was subject to a thorough manual quality control (QC).  Over 30,000 corrections were made to the classification.  Accuracy assessments from previous UTC land cover datasets indicate that the use OBIA techniques in combination with a detailed QC yield an overall accuracy of 95% or better.

Logical_Consistency_Report:

No gaps or overlaps exist.

Completeness_Report:

Complete for 2009 based on current Montgomery County boundary.

Horizontal_Positional_Accuracy_Report:

Based on LiDAR

Process_Description:

Object based image analysis (OBIA) using a rule-based expert system

Process_Description:

Manual corrections to land cover classification

Attribute_Definition:

Internal feature number.

Attribute_Definition_Source:

ESRI

Attribute_Definition:

Feature geometry.

Attribute_Definition_Source:

ESRI

Address:

115 Land and Water Building

Distribution_Liability:

The USER shall indemnify, save harmless, and, if requested, defend those parties involved with the development and distribution of this data, their officers, agents, and employees from and against any suits, claims, or actions for injury, death, or property damage arising out of the use of or any defect in the FILES or any accompanying documentation. Those parties involved with the development and distribution excluded any and all implied warranties, including warranties or merchantability and fitness for a particular purpose and makes no warranty or representation, either express or implied, with respect to the FILES or accompanying documentation, including its quality, performance, merchantability, or fitness for a particular purpose. The FILES and documentation are provided "as is" and the USER assumes the entire risk as to its quality and performance. Those parties involved with the development and distribution of this data will not be liable for any direct, indirect, special, incidental, or consequential damages arising out of the use or inability to use the FILES or any accompanying documentation.

Address:

81 Carrigan Drive

Address:

Aiken Center Room 220

Full Metadata

Land Cover, 2009, Montgomery County