Scott E Budge | Utah State University (original) (raw)

Papers by Scott E Budge

Improved registration for 3D image creation using multiple texel images and incorporating low-cos... more Improved registration for 3D image creation using multiple texel images and incorporating low-cost GPS/INS measurements

2005 Annual Report …, 2005

... User Manual” [6] Celoxica, Inc.,“Platform Developer's Kit–DSM User Manual” [7] SE Bu... more ... User Manual” [6] Celoxica, Inc.,“Platform Developer's Kit–DSM User Manual” [7] SE Budge, AM Mayampurath, and JC Solinsky,“Real-time ... on ammonia borane as a possible solidstate material Benjamin A. Schmid University of Oregon Eugene, OR and S. Thomas Autrey Pacific ...

Proceedings of SPIE, May 5, 2017

In the design or selection of a Doppler lidar instrument for a spacecraft landing system, it is i... more In the design or selection of a Doppler lidar instrument for a spacecraft landing system, it is important to evaluate the balance between performance requirements and cost, weight, and power consumption. Leveraging the capability of LadarSIM, a trade-off study was performed to evaluate the interaction between the laser transmission power, aperture diameter, and FFT size in a Doppler lidar system. For this study the probabilities of detection and false alarm were calculated using LadarSIM to simulate FMCW lidar systems with varying power, aperture diameter, and FFT size. This paper reports the results of this trade-off study.

It is imperative for a transit system to track statistics about their ridership in order to plan ... more It is imperative for a transit system to track statistics about their ridership in order to plan bus routes. There exists a wide variety of methods for obtaining these statistics that range from relying on the driver to count people to utilizing cameras and sensors. Utah State University (USU) has undertaken the task of creating a high accuracy people counter using a texel camera. The project has two main objectives. The rst and most important is to develop a system that accurately counts the number of people entering and exiting a bus. The second is to associate each exiting passenger with a passenger that previously entered. This information will better allow a transit system to track usage of buses and stops. The project has been divided into two phases. This report covers the work done in phase I. Phase II would be carried out under additional funding. The primary goal of phase I is to develop a proof of concept system for the people counter with the software algorithms needed to perform accurately. Phase II will involve the optimization of the algorithms used and the design and manufacturing of a prototype system that can be installed a bus. The optimization will be performed at USU, while VPI Engineering (a third-party interested in commercial system production) will work to produce a prototype system.

The use of a human visual model based distortion measure for image coding and evaluation is descr... more The use of a human visual model based distortion measure for image coding and evaluation is described. Test results show that when an image is encoded using the visual model, the measured quality correlates better with visual quality when the measurements are made within the model, and better images are produced.

Autonomous Systems: Sensors, Processing and Security for Ground, Air, Sea, and Space Vehicles and Infrastructure 2023

A method of vector quantization which uses a color model of the human visual system to improve th... more A method of vector quantization which uses a color model of the human visual system to improve the quality of encoded im- ages is presented. In this method, the images are first transformed into a "perceptual space" and then encoded. After reconstruction, the image is transformed back into an intensity represen- tation for viewing. A comparison is made between images en- coded at 1.125 bits per pixel with and without the visual model using both a SNR measure and visual observation. Experimental results indi- cate that there is a sigxiflcant improvement in the perceived quality of the images encoded in the visual model, although the measured distor- tion between the images is slightly better for the intensity encoded images.

Optical Engineering, 2016

The ability to create three-dimensional (3-D) image models, using registered texel images (fused ... more The ability to create three-dimensional (3-D) image models, using registered texel images (fused ladar and digital imagery), is an important topic in remote sensing. These models are automatically generated by matching multiple texel images into a single common reference frame. However, rendering a sequence of independently registered texel images often provides challenges. Although accurately registered, the model textures are often incorrectly overlapped and interwoven when using standard rendering techniques. Consequently, corrections must be done after all the primitives have been rendered by determining the best texture for any viewable fragment in the model. This paper describes a technique to visualize a 3-D model image created from a set of registered texel images. The visualization is determined for each viewpoint. It is, therefore, necessary to determine which textures are overlapping and how to best combine them dynamically during the rendering process. The best texture for a particular pixel can be defined using 3-D geometric criteria, in conjunction with a real-time, view-dependent ranking algorithm. As a result, overlapping texture fragments can now be hidden, exposed, or blended according to their computed measure of reliability. The advantages of this technique are illustrated using artificial and real data examples.

Laser Radar Technology and Applications XXIII, 2018

Methods for the creation of Textured Digital Surface Models (TDSM), which are a 3D representation... more Methods for the creation of Textured Digital Surface Models (TDSM), which are a 3D representation of a terrain surface, are of increasing interest. This paper investigates the prospects for the generation of higher resolution TDSMs using texel images taken from a low cost unmanned aerial system (UAS). Coarse measurements for attitude and position are obtained from a low cost GPS/IMU fitted into the UAS. Using these coarse measurements and the data from the texel image, the error in the camera position and attitude is reduced which helps in producing an accurate TDSM. The main reason for using texel images is that these images contain both 2D image data and 3D lidar data. Despite having many texel images as input, the out- put TDSM reported previously only has approximately same resolution as the input texel image. In this pa- per, we propose a method to combine these low resolution texel images to produce a TDSM with high resolution texture using multi-frame Wiener filter super- resolution. The final image has the resolution at the sub-pixel level instead of pixel level and because of this, the TDSM looks visually better. The improvement pro- vided by implementing super-resolution on the texture is reported and the final registered TDSM results are shown.

Laser Radar Technology and Applications XXIV, 2019

There is currently a growing need for scientifically accurate terrain maps of the earth. One way ... more There is currently a growing need for scientifically accurate terrain maps of the earth. One way to develop terrain maps includes the use of LIDAR sensing and digital imagery. By fusing these sets of data, a textured digital elevation map (TDEM) can be created. The high cost of equipment and full-scale aircraft operation can be mitigated by creating a sensor package that includes both LIDAR and digital imaging that can be mounted on a low-cost, small, unmanned aerial system (sUAS). This sensor package is called a texel camera (TC) and is composed of commercial off the shelf sensors: LIDAR, digital camera, inertial navigation system, and computer processing unit. The TC is calibrated so that each data sample contains a LIDAR scan, registered digital image, aircraft attitude, position data, and timestamp. As the TC acquires data, a point cloud is created that describes the surface of the object. Each LIDAR measurement in a scan corresponds with a known pixel in the digital image. Fusing this data allows the formation of scientifically accurate TDEMs. The TC is a more cost-effective terrain mapping solution than current mobile and manual data collection methods. It is designed to fit in rotorcraft and fixedwing sUAS. Other advantages to the TC include adaptability with existing sUAS and the ability to map views from different perspectives.

In this paper we present a new technique for texturing a Digital Surface Map (DSM) formed using a... more In this paper we present a new technique for texturing a Digital Surface Map (DSM) formed using a series of texel images (fused digital image/lidar) taken from a low-cost small unmanned aerial vehicle (UAV). In previous algorithms, an orthonormal view and a single beam had been used to texture the output DSM. The problem of using orthorectified texture obtained from such a view and a lidar scanner with multiple beams is addressed, and a new technique is described where the texture is selected based on the orientation of the triangular mesh formed by tessellating the 3D points from the lidar point cloud. This paper demonstrates the improvement in quality of the output textured DSM when viewed from various viewpoints in a 3D viewer. The stretched pixels are reduced and the texture of the side of objects is greatly improved. The final output textured DSM is shown and the improvement over the previous method is reported.

Microscopy Research and Technique, 2007

High speed data registration is required for the study of fluorescence resonance energy transfer ... more High speed data registration is required for the study of fluorescence resonance energy transfer in real time as well as fast dynamic intra- and inter-cellular signaling events. Multispectral confocal spinning disk microscopy provides a high resolution method for performing such real time live cell imaging. However, optical distortions and the physical misalignments introduced by the use of multiple acquisition cameras can obscure spatial information contained in the captured images. In this manuscript, we describe a multispectral method for real time image registration whereby the image from one camera is warped onto the image from a second camera via a polynomial correction. This method provides a real time pixel-for-pixel match between images obtained over physically distinct optical paths. Using an in situ calibration method, the polynomial is characterized by a set of coefficients, using a least squares solver. Error analysis demonstrates optimal performance results from the use of cubic polynomials. High-speed evaluation of the warp is then performed through forward differencing with fixed-point data types. Forward differencing is an iterative approach for evaluating polynomials on the condition that the function variable changes with constant steps. Image reconstruction errors are reduced through bilinear interpolation. The registration techniques described here allow for successful registration of multispectral images in real time (exceeding 15 frame/s) and have a broad applicability to imaging methods requiring pixel matching over multiple data channels.

Autonomous Systems: Sensors, Processing and Security for Ground, Air, Sea and Space Vehicles and Infrastructure 2022

Upcoming missions to explore planetary bodies in the solar system will require accurate position ... more Upcoming missions to explore planetary bodies in the solar system will require accurate position and velocity data during descent in order to land safely at a predesignated site. A Doppler lidar instrument could provide measurements of the altitude, attitude, and velocity of the landing vehicle to supplement the data collected by other instruments. A flexible simulation tool would aid the tasks of designing and testing the functionality of such an instrument. LadarSIM is a robust parameterized simulation tool developed for time of flight lidar at Utah State University's Center for Advanced Imaging Ladar. This thesis outlines how LadarSIM was modified to include a simulation of Doppler lidar. A study is performed using LadarSIM to determine the effects of varying certain parameters of a Doppler lidar system. Point clouds of landing scenarios generated by the simulation with different scanning patterns are shown.

Autonomous Systems: Sensors, Processing, and Security for Vehicles and Infrastructure 2021, 2021

Most LiDAR point cloud processing techniques continue to gather more data as the data is availabl... more Most LiDAR point cloud processing techniques continue to gather more data as the data is available. This is also typical in most imaging systems, especially visible light camera systems. We propose a computationally efficient solution where data only continues to be processed if the data has changed. Once points are received by the LiDAR hardware driver, a sensor frame spatial event filter is used to compare a previous point with the most recent point obtained from that same coordinate in the LiDAR's receptor array. The output of the event filter then fills an array of events, or event map, that will be accessible by a layer of neurons that can be implemented in a GPU. The operations per point are compared between this event-based solution and other similar solutions. We show the event-based solution's efficiency can be better, according to how much the scene is changing and how many post-processing steps are involved. Point cloud data is collected from a LiDAR mounted on a vehicle driving in paved road conditions to illustrate the concept.

IEEE Transactions on Geoscience and Remote Sensing, 2019

Reconstructing a 3-D scene from aerial sensor data creating a textured digital surface model (TDS... more Reconstructing a 3-D scene from aerial sensor data creating a textured digital surface model (TDSM), consisting of a LiDAR point cloud and an overlaid image, is valuable in many applications including agriculture, military, surveying, and natural disaster response. When collecting LiDAR from an aircraft, the navigation system accuracy must exceed the LiDAR accuracy to properly reference returns in 3-D space. Precision navigation systems can be expensive and often require full-scale aircraft to house such systems. Synchronizing the LiDAR sensor and a camera, using a texel camera calibration, provides additional information that reduces the need for precision navigation equipment. This paper describes a bundle adjustment technique for aerial texel images that allows for relatively low-accuracy navigation systems to be used with low-cost LiDAR and camera data to form higher fidelity terrain models. The bundle adjustment objective function utilizes matching image points, measured LiDAR distances, and the texel camera calibration and does not require overlapping LiDAR scans or ground control points. The utility of this method is proven using a simulated texel camera and unmanned aerial system (UAS) flight data created from aerial photographs and elevation data. A small UAS is chosen as the target vehicle due to its relatively inexpensive hardware and operating costs, illustrating the power of this method in accurately referencing the LiDAR and camera data. In the 3-D reconstruction, the 1-accuracy between LiDAR measurements across the scene is on the order of the digital camera pixel size.

Laser Radar Technology and Applications XXII, 2017

Formation of a Textured Digital Elevation Model (TDEM) has been useful in many applications in th... more Formation of a Textured Digital Elevation Model (TDEM) has been useful in many applications in the fields of agriculture, disaster response, terrain analysis and more. Use of a low-cost small UAV system with a texel camera (fused lidar/digital imagery) can significantly reduce the cost compared to conventional aircraft-based methods. This paper reports continued work on this problem reported in a previous paper by Bybee and Budge, and reports improvements in performance. A UAV fitted with a texel camera is flown at a fixed height above the terrain and swaths of texel image data of the terrain below is taken continuously. Each texel swath has one or more lines of lidar data surrounded by a narrow strip of EO data. Texel swaths are taken such that there is some overlap from one swath to its adjacent swath. The GPS/IMU fitted on the camera also give coarse knowledge of attitude and position. Using this coarse knowledge and the information from the texel image, the error in the camera position and attitude is reduced which helps in producing an accurate TDEM. This paper reports improvements in the original work by using multiple lines of lidar data per swath. The final results are shown and analyzed for numerical accuracy.

Improved registration for 3D image creation using multiple texel images and incorporating low-cos... more Improved registration for 3D image creation using multiple texel images and incorporating low-cost GPS/INS measurements

2005 Annual Report …, 2005

... User Manual” [6] Celoxica, Inc.,“Platform Developer's Kit–DSM User Manual” [7] SE Bu... more ... User Manual” [6] Celoxica, Inc.,“Platform Developer's Kit–DSM User Manual” [7] SE Budge, AM Mayampurath, and JC Solinsky,“Real-time ... on ammonia borane as a possible solidstate material Benjamin A. Schmid University of Oregon Eugene, OR and S. Thomas Autrey Pacific ...

Proceedings of SPIE, May 5, 2017

In the design or selection of a Doppler lidar instrument for a spacecraft landing system, it is i... more In the design or selection of a Doppler lidar instrument for a spacecraft landing system, it is important to evaluate the balance between performance requirements and cost, weight, and power consumption. Leveraging the capability of LadarSIM, a trade-off study was performed to evaluate the interaction between the laser transmission power, aperture diameter, and FFT size in a Doppler lidar system. For this study the probabilities of detection and false alarm were calculated using LadarSIM to simulate FMCW lidar systems with varying power, aperture diameter, and FFT size. This paper reports the results of this trade-off study.

It is imperative for a transit system to track statistics about their ridership in order to plan ... more It is imperative for a transit system to track statistics about their ridership in order to plan bus routes. There exists a wide variety of methods for obtaining these statistics that range from relying on the driver to count people to utilizing cameras and sensors. Utah State University (USU) has undertaken the task of creating a high accuracy people counter using a texel camera. The project has two main objectives. The rst and most important is to develop a system that accurately counts the number of people entering and exiting a bus. The second is to associate each exiting passenger with a passenger that previously entered. This information will better allow a transit system to track usage of buses and stops. The project has been divided into two phases. This report covers the work done in phase I. Phase II would be carried out under additional funding. The primary goal of phase I is to develop a proof of concept system for the people counter with the software algorithms needed to perform accurately. Phase II will involve the optimization of the algorithms used and the design and manufacturing of a prototype system that can be installed a bus. The optimization will be performed at USU, while VPI Engineering (a third-party interested in commercial system production) will work to produce a prototype system.

The use of a human visual model based distortion measure for image coding and evaluation is descr... more The use of a human visual model based distortion measure for image coding and evaluation is described. Test results show that when an image is encoded using the visual model, the measured quality correlates better with visual quality when the measurements are made within the model, and better images are produced.

Autonomous Systems: Sensors, Processing and Security for Ground, Air, Sea, and Space Vehicles and Infrastructure 2023

A method of vector quantization which uses a color model of the human visual system to improve th... more A method of vector quantization which uses a color model of the human visual system to improve the quality of encoded im- ages is presented. In this method, the images are first transformed into a "perceptual space" and then encoded. After reconstruction, the image is transformed back into an intensity represen- tation for viewing. A comparison is made between images en- coded at 1.125 bits per pixel with and without the visual model using both a SNR measure and visual observation. Experimental results indi- cate that there is a sigxiflcant improvement in the perceived quality of the images encoded in the visual model, although the measured distor- tion between the images is slightly better for the intensity encoded images.

Optical Engineering, 2016

The ability to create three-dimensional (3-D) image models, using registered texel images (fused ... more The ability to create three-dimensional (3-D) image models, using registered texel images (fused ladar and digital imagery), is an important topic in remote sensing. These models are automatically generated by matching multiple texel images into a single common reference frame. However, rendering a sequence of independently registered texel images often provides challenges. Although accurately registered, the model textures are often incorrectly overlapped and interwoven when using standard rendering techniques. Consequently, corrections must be done after all the primitives have been rendered by determining the best texture for any viewable fragment in the model. This paper describes a technique to visualize a 3-D model image created from a set of registered texel images. The visualization is determined for each viewpoint. It is, therefore, necessary to determine which textures are overlapping and how to best combine them dynamically during the rendering process. The best texture for a particular pixel can be defined using 3-D geometric criteria, in conjunction with a real-time, view-dependent ranking algorithm. As a result, overlapping texture fragments can now be hidden, exposed, or blended according to their computed measure of reliability. The advantages of this technique are illustrated using artificial and real data examples.

Laser Radar Technology and Applications XXIII, 2018

Methods for the creation of Textured Digital Surface Models (TDSM), which are a 3D representation... more Methods for the creation of Textured Digital Surface Models (TDSM), which are a 3D representation of a terrain surface, are of increasing interest. This paper investigates the prospects for the generation of higher resolution TDSMs using texel images taken from a low cost unmanned aerial system (UAS). Coarse measurements for attitude and position are obtained from a low cost GPS/IMU fitted into the UAS. Using these coarse measurements and the data from the texel image, the error in the camera position and attitude is reduced which helps in producing an accurate TDSM. The main reason for using texel images is that these images contain both 2D image data and 3D lidar data. Despite having many texel images as input, the out- put TDSM reported previously only has approximately same resolution as the input texel image. In this pa- per, we propose a method to combine these low resolution texel images to produce a TDSM with high resolution texture using multi-frame Wiener filter super- resolution. The final image has the resolution at the sub-pixel level instead of pixel level and because of this, the TDSM looks visually better. The improvement pro- vided by implementing super-resolution on the texture is reported and the final registered TDSM results are shown.

Laser Radar Technology and Applications XXIV, 2019

There is currently a growing need for scientifically accurate terrain maps of the earth. One way ... more There is currently a growing need for scientifically accurate terrain maps of the earth. One way to develop terrain maps includes the use of LIDAR sensing and digital imagery. By fusing these sets of data, a textured digital elevation map (TDEM) can be created. The high cost of equipment and full-scale aircraft operation can be mitigated by creating a sensor package that includes both LIDAR and digital imaging that can be mounted on a low-cost, small, unmanned aerial system (sUAS). This sensor package is called a texel camera (TC) and is composed of commercial off the shelf sensors: LIDAR, digital camera, inertial navigation system, and computer processing unit. The TC is calibrated so that each data sample contains a LIDAR scan, registered digital image, aircraft attitude, position data, and timestamp. As the TC acquires data, a point cloud is created that describes the surface of the object. Each LIDAR measurement in a scan corresponds with a known pixel in the digital image. Fusing this data allows the formation of scientifically accurate TDEMs. The TC is a more cost-effective terrain mapping solution than current mobile and manual data collection methods. It is designed to fit in rotorcraft and fixedwing sUAS. Other advantages to the TC include adaptability with existing sUAS and the ability to map views from different perspectives.

In this paper we present a new technique for texturing a Digital Surface Map (DSM) formed using a... more In this paper we present a new technique for texturing a Digital Surface Map (DSM) formed using a series of texel images (fused digital image/lidar) taken from a low-cost small unmanned aerial vehicle (UAV). In previous algorithms, an orthonormal view and a single beam had been used to texture the output DSM. The problem of using orthorectified texture obtained from such a view and a lidar scanner with multiple beams is addressed, and a new technique is described where the texture is selected based on the orientation of the triangular mesh formed by tessellating the 3D points from the lidar point cloud. This paper demonstrates the improvement in quality of the output textured DSM when viewed from various viewpoints in a 3D viewer. The stretched pixels are reduced and the texture of the side of objects is greatly improved. The final output textured DSM is shown and the improvement over the previous method is reported.

Microscopy Research and Technique, 2007

High speed data registration is required for the study of fluorescence resonance energy transfer ... more High speed data registration is required for the study of fluorescence resonance energy transfer in real time as well as fast dynamic intra- and inter-cellular signaling events. Multispectral confocal spinning disk microscopy provides a high resolution method for performing such real time live cell imaging. However, optical distortions and the physical misalignments introduced by the use of multiple acquisition cameras can obscure spatial information contained in the captured images. In this manuscript, we describe a multispectral method for real time image registration whereby the image from one camera is warped onto the image from a second camera via a polynomial correction. This method provides a real time pixel-for-pixel match between images obtained over physically distinct optical paths. Using an in situ calibration method, the polynomial is characterized by a set of coefficients, using a least squares solver. Error analysis demonstrates optimal performance results from the use of cubic polynomials. High-speed evaluation of the warp is then performed through forward differencing with fixed-point data types. Forward differencing is an iterative approach for evaluating polynomials on the condition that the function variable changes with constant steps. Image reconstruction errors are reduced through bilinear interpolation. The registration techniques described here allow for successful registration of multispectral images in real time (exceeding 15 frame/s) and have a broad applicability to imaging methods requiring pixel matching over multiple data channels.

Autonomous Systems: Sensors, Processing and Security for Ground, Air, Sea and Space Vehicles and Infrastructure 2022

Upcoming missions to explore planetary bodies in the solar system will require accurate position ... more Upcoming missions to explore planetary bodies in the solar system will require accurate position and velocity data during descent in order to land safely at a predesignated site. A Doppler lidar instrument could provide measurements of the altitude, attitude, and velocity of the landing vehicle to supplement the data collected by other instruments. A flexible simulation tool would aid the tasks of designing and testing the functionality of such an instrument. LadarSIM is a robust parameterized simulation tool developed for time of flight lidar at Utah State University's Center for Advanced Imaging Ladar. This thesis outlines how LadarSIM was modified to include a simulation of Doppler lidar. A study is performed using LadarSIM to determine the effects of varying certain parameters of a Doppler lidar system. Point clouds of landing scenarios generated by the simulation with different scanning patterns are shown.

Autonomous Systems: Sensors, Processing, and Security for Vehicles and Infrastructure 2021, 2021

Most LiDAR point cloud processing techniques continue to gather more data as the data is availabl... more Most LiDAR point cloud processing techniques continue to gather more data as the data is available. This is also typical in most imaging systems, especially visible light camera systems. We propose a computationally efficient solution where data only continues to be processed if the data has changed. Once points are received by the LiDAR hardware driver, a sensor frame spatial event filter is used to compare a previous point with the most recent point obtained from that same coordinate in the LiDAR's receptor array. The output of the event filter then fills an array of events, or event map, that will be accessible by a layer of neurons that can be implemented in a GPU. The operations per point are compared between this event-based solution and other similar solutions. We show the event-based solution's efficiency can be better, according to how much the scene is changing and how many post-processing steps are involved. Point cloud data is collected from a LiDAR mounted on a vehicle driving in paved road conditions to illustrate the concept.

IEEE Transactions on Geoscience and Remote Sensing, 2019

Reconstructing a 3-D scene from aerial sensor data creating a textured digital surface model (TDS... more Reconstructing a 3-D scene from aerial sensor data creating a textured digital surface model (TDSM), consisting of a LiDAR point cloud and an overlaid image, is valuable in many applications including agriculture, military, surveying, and natural disaster response. When collecting LiDAR from an aircraft, the navigation system accuracy must exceed the LiDAR accuracy to properly reference returns in 3-D space. Precision navigation systems can be expensive and often require full-scale aircraft to house such systems. Synchronizing the LiDAR sensor and a camera, using a texel camera calibration, provides additional information that reduces the need for precision navigation equipment. This paper describes a bundle adjustment technique for aerial texel images that allows for relatively low-accuracy navigation systems to be used with low-cost LiDAR and camera data to form higher fidelity terrain models. The bundle adjustment objective function utilizes matching image points, measured LiDAR distances, and the texel camera calibration and does not require overlapping LiDAR scans or ground control points. The utility of this method is proven using a simulated texel camera and unmanned aerial system (UAS) flight data created from aerial photographs and elevation data. A small UAS is chosen as the target vehicle due to its relatively inexpensive hardware and operating costs, illustrating the power of this method in accurately referencing the LiDAR and camera data. In the 3-D reconstruction, the 1-accuracy between LiDAR measurements across the scene is on the order of the digital camera pixel size.

Laser Radar Technology and Applications XXII, 2017

Formation of a Textured Digital Elevation Model (TDEM) has been useful in many applications in th... more Formation of a Textured Digital Elevation Model (TDEM) has been useful in many applications in the fields of agriculture, disaster response, terrain analysis and more. Use of a low-cost small UAV system with a texel camera (fused lidar/digital imagery) can significantly reduce the cost compared to conventional aircraft-based methods. This paper reports continued work on this problem reported in a previous paper by Bybee and Budge, and reports improvements in performance. A UAV fitted with a texel camera is flown at a fixed height above the terrain and swaths of texel image data of the terrain below is taken continuously. Each texel swath has one or more lines of lidar data surrounded by a narrow strip of EO data. Texel swaths are taken such that there is some overlap from one swath to its adjacent swath. The GPS/IMU fitted on the camera also give coarse knowledge of attitude and position. Using this coarse knowledge and the information from the texel image, the error in the camera position and attitude is reduced which helps in producing an accurate TDEM. This paper reports improvements in the original work by using multiple lines of lidar data per swath. The final results are shown and analyzed for numerical accuracy.