Typical data acquisitions are for areas of approximately 10 km across-track (range direction) and up to 1500 km along track (azimuth direction), collected at a coverage rate of up to 100km2 every minute.

Several competing technologies, such as the more familiarLIDAR system, are used to generate map products at various scales, details, and accuracies. However, experts in the geospatial community recognize the fact that airborne IFSAR has matured as a complementary or even competitive 3D mapping technology.

The IFSAR data collection process wasn’t developed to satisfy everyone’s mapping needs. However, depending on the scope and requirements of a particular project, IFSAR is a proven alternative to LIDAR. In addition, IFSAR’s ability to complement a LIDAR end-product with precise, less-expensive elevation data and geometries can save considerable time and money for organisations.

Intermap is proactively meeting the growing global demand for superior, low-cost digital elevation datasets, imageries, and geometric models. The experienced team of airborne IFSAR technology experts continue to take the geospatial mapping industry to an incomparable level of accuracy and affordability. Likewise, the NEXTMap® suite of off-the-shelf products, along with custom collections, has enabled a wide range of geospatial solutions for numerous commercial, government, military, and consumer applications, worldwide.

 

Core Product Specifications

 

Core products are created according to tightly controlled specifications:

 

Digital Surface Models (DSM)   DSM Measures of Accuracy Specifications Pixel Size/ Product Type RMSE CE95 Post Spacing I 0.5 m 1.0 m 5 m II 1.0 m 2.0 m 5 m III 3.0 m 6.0 m 5 m

 

Digital Terrain Models (DTM)   DSM Measures of Accuracy Specifications Pixel Size/ Product Type RMSE CE95 Post Spacing I 0.7 m 1.5 m 5 m II 1.0 m 2.0 m 5 m

Orthorectified Radar Images (ORI) Product Type RMSE CE95 1.25 m 2.0 m 4.0 m

 

NOTES (DSM/DTM):
Elevation postings are every 5 meters (2.5m postings available in 2008).

RMSE: The Root Mean Square Error is derived from a statistical formula for measuring the accuracy of our data against independently obtained “truth” data. The resulting RMSE value is a measure of the difference between these two sets of data. The stated values for DSM and DTM RMSE are in unobstructed areas wtih slopes less than 10 degrees. See Section 5.3, Product Quality for more information on factors affecting product quality and accuracy.

CE95: The Circular Error 95 methodology is a spatial accuracy assessment, which requires that 95% of the data fall within the radius specified.

Slopes greater than twenty degrees cause reduced accuracy. The impact depends on the magnitude of the slope, whether the slope is positive or negative, aspect angle, and where it lies in the radar swath (look angle). A general rule of thumb is that the error will double on slopes of twenty to thirty degrees and will increase as slope increases.