The LAS (LASer) format is a file format designed for the interchange and archiving of

lidar Lidar (, also LIDAR, or LiDAR; sometimes LADAR) is a method for determining ranges (variable distance) by targeting an object or a surface with a laser and measuring the time for the reflected light to return to the receiver. It can also be ...

point cloud Point or points may refer to: Places * Point, Lewis, a peninsula in the Outer Hebrides, Scotland * Point, Texas, a city in Rains County, Texas, United States * Point, the NE tip and a ferry terminal of Lismore, Inner Hebrides, Scotland * Point ...

data. It is an open,

binary Binary may refer to: Science and technology Mathematics * Binary number, a representation of numbers using only two digits (0 and 1) * Binary function, a function that takes two arguments * Binary operation, a mathematical operation that ta ...

format specified by the

American Society for Photogrammetry and Remote Sensing The American Society for Photogrammetry and Remote Sensing (ASPRS) is an American learned society devoted to photogrammetry and remote sensing. It is the United States' member organization of the International Society for Photogrammetry and Remot ...

(ASPRS). The format is widely used and regarded as an industry standard for lidar data.

File structure

A LAS file consists of the following overall sections:

Point data records

A LAS file contains point records in one of the point data record formats defined by the LAS specification; as of LAS 1.4, there are 11 point data record formats (0 through 10) available. All point data records must be of the same format within the file. The various formats differ in the data fields available, such as

GPS time The Global Positioning System (GPS), originally Navstar GPS, is a satellite-based radionavigation system owned by the United States government and operated by the United States Space Force. It is one of the global navigation satellite sys ...

RGB The RGB color model is an additive color model in which the red, green and blue primary colors of light are added together in various ways to reproduce a broad array of colors. The name of the model comes from the initials of the three additiv ...

and NIR color and wave packet information. The 3D point coordinates are represented within the point data records by 32-bit integers, to which a scaling and offset defined in the public header must be applied in order to obtain the actual coordinates. As the number of bytes used per point data record is explicitly given in the public header block, it is possible to add user-defined fields in "extra bytes" to the fields given by the specification-defined point data record formats. A standardized way of interpreting such extra bytes was introduced in the LAS 1.4 specification, in the form of a specific EVLR.

Compression

LAS file format is not compressed, but there is an open source project LASzip which defined the open file format LAZ to losslessly compress LAS data.

References

External links

LASer (LAS) File Format Exchange Activities
at

Official ASPRS LAS Page
on

GitHub GitHub, Inc. () is an Internet hosting service for software development and version control using Git. It provides the distributed version control of Git plus access control, bug tracking, software feature requests, task management, co ...

GIS file formats {{Software-stub