USGS 20071210 Lidar data Unknown Unknown Reston,VA USGS LIDAR-derived binary (.las) files containing classified points of all returns. We have 4 classifications Unclassified, Ground, Low Points and Water. The total area covers approximately 1,035 square miles. Thes tiles are delivered in Digital Ortho Quarter-Quarter Quad format. Unknown 1) Geoid 2003 2) All of the GPS coordinates were referenced to the following NGS (Natioal Geodetic Survey) points designated as: V 1439 (PID #AP0159) F 1436 ((PID #AO0496) G 1432 (PID #AZ0495) ROW (PID #AO0338) 3) 6 GPS Base Stations were used for this project. Maximum baseline length to the end of the project boundary limits was approximately 24 miles and the mean baseline length was approximately 14 miles. 4) Nominal pulse density: Area 1 = 41,000 Hz Area 2 = 40,000 Hz 5) A LiDAR calibration or 'boresight' is performed on every mission to determine and eliminate systemic biases that occur within the hardware of the Leica ALS50 laser scanning system, the inertial measurement unit (IMU), and because of environmental conditions which affect the refraction of light. The systemic biases that are corrected for include roll, pitch, and heading. In order to correct the error in the data, misalignments of features in the overlap areas of the lidar flightlines must be detected and measured. At some point within the mission, a specfic flight pattern must be flown which shows all the misalignments that can be present. Typically, Merrick flies a pattern of at least three opposing direction and overlapping lines, three of which provide all the information required to calibrate the system. 20071003 unknown 20080131 unknown ground condition Complete As needed -100.180551 -100.155940 28.125294 28.106593 None LAS LIDAR Elevation None Mexican-Texas Border Mexico Texas USA None 2007 2008 none none USGS National Center for Earth Resources Observation & Science (EROS) mailing and physical address

Customer Services, USGS National Center for Earth Resources Observation & Science (EROS)

Sioux Falls South Dakota 57198-0001 USA +001 605-594-6151 1-800-252-4547 +001 605-594-6933 +001 605-594-6589 custserv@usgs.gov 0800 - 1600 CT, M-F, -6 h GMT none Merrick & Company Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.2.5.1450 Verification of attribute accuracy of LIDAR data involves the use of filtering techniques. Auto-filtering uses algorithms to reclassify data in the point cloud. Hand-filtering involves the use of a technician working in a graphic environment to reclassify the erroneous points that may remain in the LIDAR point cloud after auto filter. n/a n/a Calibrations of the LIDAR flightline data are performed; this process is known as boresighting. The flightlines are compared to evaluate both their relative and absolute accuracies. This dataset contains unclassified returns of the LIDAR sensor. The sensor data was verified in MARS software to ensure complete coverage. Horizontal accuracy is verified in three tests. During boresighting, adjoining flightlines are view in profile and hard edged features are observed and if necessary the flightlines are adjusted for good relative horizontal and vertical fit. The second test for horizontal accuracy is by comparing raw contours from each flightline against adjoining flightlines at specific points. The final test is the vertical LIDAR control report. .7 meter This value is an estimation Survey control points were used to validate the accuracy of the LIDAR surface model after automatic and hand filtering. This surface exceeds the NSSDA vertical accuracy specifications of .15 meters.. 0.07 meters preliminary This value is measured as RMSEz. Merrick & Company 20071201 spreadsheet Aurora, CO Merrick & Company disc 20071003 unknown 20080131 unknown ground condition GROUND_CONTROL GPS control network for LIDAR acquisition and processing. Merrick & Company 20071201 point digital data Aurora, CO Merrick & Company disc 20071003 unknown 20080131 unknown ground condition LIDAR LIDAR points form the basis of the DTM surface. LIDAR data was collected using Merrick's ALS50 Phase 2 sensor. The raw data was verified in MARS software for complete coverage of the project area, and boresighted to align the flightlines. Raw data files were parsed into manageable client-specific tiles. These tiles were then processed through automated filtering that separates the data into different classification groups: unclassified points, ground points, low points and water. The data was next taken into MARS to reclassify the erroneous points that may remain in the LIDAR point cloud after auto filter. LIDAR GROUND_CONTROL 20071210 Doug Jacoby Merrick & Company Director of Projects / Project Manager mailing and physical address

2450 South Peoria Street

Aurora CO 80014 U.S.A. 303-353-3903 303-745-0964 doug.jacoby@merrick.com 8 am - 5 pm, Mountain Time Zone, Monday thru Friday Call or email during business hours 0% Point Universal Transverse Mercator 14 0.999600 -99.000000 0.000000 500000.000000 0.000000 row and column .001 .001 meters D_WGS_1984 WGS_1984 6378137.000000 298.257224 North American Vertical Datum of 1988 0.001 meters Implicit coordinate LAS Las Data Merrick Attributes inclued in the LAS file include: x-coord in meters (double) precision .001 y-coord in meters (double) precision .001 elevation in meters (double) precision .001 classification (interger) 1 = Unclassified, 2 = Ground, 7 = Low Points, 9 = Water Intensity (interger) range 0 -255 Valid USGS National Center for Earth Resources Observation & Science (EROS) mailing and physical address

Customer Services, USGS National Center for Earth Resources Observation & Science (EROS)

Sioux Falls South Dakota 57198-0001 +001 605-594-6151 1-800-252-4547 +001 605-594-6933 +001 605-594-6589 custserv@usgs.gov 0800 - 1600 CT, M-F, -6 h GMT none Downloadable Data Although these data have been processed successfully on a computer system at the U.S. Geological Survey (USGS), no warranty expressed or implied is made by the USGS regarding the utility of the data on any other system, nor shall the act of distribution constitute any such warranty. The USGS will warrant the delivery of this product in computer-readable format and will offer appropriate adjustment of credit when the product is determined unreadable by correctly adjusted computer input peripherals or when the physical medium is delivered in damaged condition. Requests for adjustment of credit must be made within 90 days from the date of this shipment from the ordering site. 20080417 Roger Hanson Merrick & Company Director of Operations mailing and physical address

2450 South Peoria Street

Aurora CO 80014 U.S.A. 303-353-3878 303-751-0741 303-745-0964 roger.hanson@merrick.com 8 am - 5 pm, Mountain Time Zone, Monday thru Friday Call or email during business hours FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998 local time Unknown Unknown Unknown Unknown Unknown http://www.esri.com/metadata/esriprof80.html ESRI Metadata Profile http://www.esri.com/metadata/esriprof80.html ESRI Metadata Profile