In one implementation, a device has a processor, a projector, a first infrared (IR) sensor, a second IR sensor, and instructions stored on a computer-readable medium that are executed by the processor to estimate the sensor-to-sensor extrinsic parameters. The projector projects IR pattern elements onto an environment surface. The first sensor captures a first image including first IR pattern elements corresponding to the projected IR pattern elements and the device estimates 3D positions for first IR pattern elements. The second IR sensor captures a second image including second IR pattern elements corresponding to the projected IR pattern elements and the device matches the first IR pattern elements and the second IR pattern elements. Based on this matching, the device estimates a second extrinsic parameter corresponding to a spatial relationship between the first IR sensor and the second IR sensor.