# Precision landing in SITL issue **URL:** \ **Category:** PX4 Autopilot\ **Created:** [November 5, 2018, 3:44pm UTC](https://discuss.px4.io/t/precision-landing-in-sitl-issue/8369 "2018-11-05T15:44:40Z")\ **Posts on this page:** 16\ **Page:** 1
**Author:** ![tbrs2](https://discuss.px4.io/letter_avatar_proxy/v4/letter/t/a4c791/32.png) [@tbrs2](https://discuss.px4.io/u/tbrs2)\ **Post date:** [November 5, 2018, 3:44pm UTC](https://discuss.px4.io/t/precision-landing-in-sitl-issue/8369/1 "2018-11-05T15:44:40Z")
Hi all, I tried to get precision landing to work following the documentation guide here [https://docs.px4.io/en/advanced\_features/precland.html](https://docs.px4.io/en/advanced_features/precland.html) I can successfully run make posix\_sitl\_default gazebo\_iris\_irlock but when I try to run it with drivers/irlock added to the posix\_sitl\_default config file, I get the following from std out * * * ## zebo\_iris\_irlock ninja: Entering directory `/home/tom/px4/px4\_toolchain/src/Firmware/build/posix\_sitl\_default’ [1/1] Re-running CMake… – PX4 VERSION: v1.8.0-1508-gd3b54c35 – CONFIG: posix\_sitl\_default – Build Type: RelWithDebInfo – C compiler: cc (Ubuntu 5.4.0-6ubuntu1~16.04.10) 5.4.0 20160609 – C++ compiler: c++ (Ubuntu 5.4.0-6ubuntu1~16.04.10) 5.4.0 20160609 – PX4 ECL: Very lightweight Estimation & Control Library v0.9.0-590-g2354c30 – Configuring done – Generating done – Build files have been written to: /home/tom/px4/px4\_toolchain/src/Firmware/build/posix\_sitl\_default [3/139] Performing configure step for ‘sitl\_gazebo’ – install-prefix: /usr/local – Boost version: 1.58.0 – Found the following Boost libraries: – system – thread – timer – chrono – date\_time – atomic – Boost version: 1.58.0 – Building klt\_feature\_tracker without catkin – Building OpticalFlow with OpenCV – catkin DISABLED Gazebo version: 7.14 – Using C++17 compiler – Configuring done – Generating done – Build files have been written to: /home/tom/px4/px4\_toolchain/src/Firmware/build/posix\_sitl\_default/build\_gazebo [17/139] Building CXX object src/drive…Files/drivers\_\_irlock.dir/irlock.cpp.o FAILED: /usr/bin/c++ -DCONFIG\_ARCH\_BOARD\_SITL -DMODULE\_NAME="irlock" -DPX4\_MAIN=irlock\_app\_main -D\_\_DF\_LINUX -D\_\_PX4\_LINUX -D\_\_PX4\_POSIX -D\_\_STDC\_FORMAT\_MACROS -Dnoreturn\_function=“ **attribute** ((noreturn))” -I. -Isrc -Isrc/lib -Isrc/modules -I../../src -I../../src/drivers/boards/sitl -I../../src/include -I../../src/lib -I../../src/lib/DriverFramework/framework/include -I../../src/lib/matrix -I../../src/modules -I../../src/platforms -I../../platforms/posix/include -Iexternal/Install/include -g -fno-exceptions -fno-rtti -std=gnu++11 -fno-threadsafe-statics -DCONFIG\_WCHAR\_BUILTIN -D\_\_CUSTOM\_FILE\_IO\_\_ -fcheck-new -Wall -Wextra -Werror -Warray-bounds -Wdisabled-optimization -Wdouble-promotion -Wfatal-errors -Wfloat-equal -Wformat-security -Winit-self -Wlogical-op -Wmissing-declarations -Wpointer-arith -Wshadow -Wuninitialized -Wunknown-pragmas -Wunused-variable -Wno-implicit-fallthrough -Wno-missing-field-initializers -Wno-missing-include-dirs -Wno-unused-parameter -Wunused-but-set-variable -Wformat=1 -Wno-overloaded-virtual -Wreorder -Wno-format-truncation -fvisibility=hidden -include visibility.h -fno-strict-aliasing -fomit-frame-pointer -fno-math-errno -funsafe-math-optimizations -ffunction-sections -fdata-sections -fno-strength-reduce -fno-builtin-printf -fdiagnostics-color=always -O2 -g -DNDEBUG -fno-strict-aliasing -fomit-frame-pointer -fno-math-errno -funsafe-math-optimizations -ffunction-sections -fdata-sections -fno-strength-reduce -fno-builtin-printf -fdiagnostics-color=always -std=gnu++11 -MMD -MT src/drivers/irlock/CMakeFiles/drivers\_\_irlock.dir/irlock.cpp.o -MF src/drivers/irlock/CMakeFiles/drivers\_\_irlock.dir/irlock.cpp.o.d -o src/drivers/irlock/CMakeFiles/drivers\_\_irlock.dir/irlock.cpp.o -c ../../src/drivers/irlock/irlock.cpp ../../src/drivers/irlock/irlock.cpp:59:25: fatal error: nuttx/clock.h: No such file or directory compilation terminated. [17/139] Performing build step for ‘sitl\_gazebo’ [1/57] Building CXX object CMakeFiles/sensor\_msgs.dir/IRLock.pb.cc.o [2/57] Building CXX object CMakeFiles/sensor\_msgs.dir/Float.pb.cc.o [3/57] Building CXX object CMakeFiles/sensor\_msgs.dir/Imu.pb.cc.o [4/57] Building CXX object CMakeFiles/sensor\_msgs.dir/Groundtruth.pb.cc.o [5/57] Building CXX object CMakeFiles/sensor\_msgs.dir/Range.pb.cc.o [6/57] Building CXX object CMakeFiles/sensor\_msgs.dir/SITLGps.pb.cc.o [7/57] Building CXX object CMakeFiles/sensor\_msgs.dir/OpticalFlow.pb.cc.o [8/57] Building CXX object CMakeFiles/mav\_msgs.dir/MotorSpeed.pb.cc.o [9/57] Building CXX object CMakeFiles/mav\_msgs.dir/CommandMotorSpeed.pb.cc.o [10/57] Building CXX object CMakeFiles/std\_msgs.dir/Int32.pb.cc.o [11/57] Building CXX object CMakeFiles/nav\_msgs.dir/Odometry.pb.cc.o [12/57] Building CXX object CMakeFiles/physics\_msgs.dir/Wind.pb.cc.o [13/57] Linking CXX shared library libmav\_msgs.so [14/57] Linking CXX shared library libstd\_msgs.so [15/57] Building CXX object OpticalFlow/klt\_feature\_tracker/CMakeFiles/klt\_feature\_tracker.dir/src/trackFeatures.cpp.o [16/57] Linking CXX shared library libsensor\_msgs.so [17/57] Linking CXX shared library libphysics\_msgs.so [18/57] Linking CXX shared library libnav\_msgs.so [19/57] Building CXX object CMakeFiles/gazebo\_motor\_model.dir/src/gazebo\_motor\_model.cpp.o [20/57] Building CXX object CMakeFiles/LiftDragPlugin.dir/src/liftdrag\_plugin/liftdrag\_plugin.cpp.o [21/57] Building CXX object CMakeFiles/gazebo\_geotagged\_images\_plugin.dir/src/gazebo\_geotagged\_images\_plugin.cpp.o [22/57] Building CXX object CMakeFiles/gazebo\_controller\_interface.dir/src/gazebo\_controller\_interface.cpp.o [23/57] Building CXX object CMakeFiles/gazebo\_mavlink\_interface.dir/src/gazebo\_mavlink\_interface.cpp.o [24/57] Building CXX object CMakeFiles/gazebo\_irlock\_plugin.dir/src/gazebo\_irlock\_plugin.cpp.o [25/57] Building CXX object CMakeFiles/gazebo\_mavlink\_interface.dir/src/geo\_mag\_declination.cpp.o [26/57] Building CXX object CMakeFiles/gazebo\_lidar\_plugin.dir/src/gazebo\_lidar\_plugin.cpp.o [27/57] Building CXX object CMakeFiles/gazebo\_wind\_plugin.dir/src/gazebo\_wind\_plugin.cpp.o [28/57] Building CXX object CMakeFiles/gazebo\_imu\_plugin.dir/src/gazebo\_imu\_plugin.cpp.o [29/57] Building CXX object CMakeFiles/gazebo\_gps\_plugin.dir/src/gazebo\_gps\_plugin.cpp.o [30/57] Linking CXX shared library libgazebo\_controller\_interface.so [31/57] Building CXX object CMakeFiles/gazebo\_sonar\_plugin.dir/src/gazebo\_sonar\_plugin.cpp.o [32/57] Linking CXX shared library libgazebo\_irlock\_plugin.so [33/57] Linking CXX shared library libgazebo\_gps\_plugin.so [34/57] Linking CXX shared library libgazebo\_wind\_plugin.so [35/57] Linking CXX shared library libgazebo\_lidar\_plugin.so [36/57] Linking CXX shared library libgazebo\_imu\_plugin.so [37/57] Linking CXX shared library libLiftDragPlugin.so [38/57] Linking CXX shared library libgazebo\_motor\_model.so [39/57] Building CXX object CMakeFiles/gazebo\_uuv\_plugin.dir/src/gazebo\_uuv\_plugin.cpp.o [40/57] Building CXX object CMakeFiles/gazebo\_vision\_plugin.dir/src/gazebo\_vision\_plugin.cpp.o [41/57] Building CXX object CMakeFiles/gazebo\_multirotor\_base\_plugin.dir/src/gazebo\_multirotor\_base\_plugin.cpp.o [42/57] Building CXX object CMakeFiles/gazebo\_gimbal\_controller\_plugin.dir/src/gazebo\_gimbal\_controller\_plugin.cpp.o [43/57] Linking CXX static library OpticalFlow/klt\_feature\_tracker/libklt\_feature\_tracker.a [44/57] Building CXX object OpticalFlow/CMakeFiles/OpticalFlow.dir/src/optical\_flow.cpp.o [45/57] Building CXX object OpticalFlow/CMakeFiles/OpticalFlow.dir/src/px4flow.cpp.o [46/57] Building CXX object OpticalFlow/CMakeFiles/OpticalFlow.dir/src/flow\_px4.cpp.o [47/57] Building CXX object OpticalFlow/CMakeFiles/OpticalFlow.dir/src/flow\_opencv.cpp.o [48/57] Linking CXX shared library OpticalFlow/libOpticalFlow.so [49/57] Building CXX object CMakeFiles/gazebo\_opticalflow\_plugin.dir/src/gazebo\_opticalflow\_plugin.cpp.o [50/57] Linking CXX shared library libgazebo\_mavlink\_interface.so [51/57] Linking CXX shared library libgazebo\_vision\_plugin.so [52/57] Linking CXX shared library libgazebo\_sonar\_plugin.so [53/57] Linking CXX shared library libgazebo\_multirotor\_base\_plugin.so [54/57] Linking CXX shared library libgazebo\_gimbal\_controller\_plugin.so [55/57] Linking CXX shared library libgazebo\_uuv\_plugin.so [56/57] Linking CXX shared library libgazebo\_geotagged\_images\_plugin.so [57/57] Linking CXX shared library libgazebo\_opticalflow\_plugin.so ninja: build stopped: subcommand failed. Makefile:170: recipe for target ‘posix\_sitl\_default’ failed make: \*\*\* [posix\_sitl\_default] Error 1 It seems it can’t find the file nuttx/clock.h I figured that in SITL, it shouldn’t be looking for any nuttx installed microcontroller? (In case anyone was wondering, the line modules/landing\_target\_estimator was already included in my config file, so I was running it with this as well). Does anyone have any ideas why I can’t build the firmware? I’m running version 1.8.0-dev by the way. Thanks, Tom ---
**Author:** ![Nicolas](https://discuss.px4.io/user_avatar/discuss.px4.io/nicolas/32/4467_2.png) [@Nicolas](https://discuss.px4.io/u/Nicolas)\ **Post date:** [November 5, 2018, 5:22pm UTC](https://discuss.px4.io/t/precision-landing-in-sitl-issue/8369/2 "2018-11-05T17:22:16Z")
For SITL, you don’t have to modify any config files. SITL also doesn’t use the nuttx irlock driver, it gets the data from gazebo. ---
**Author:** ![tbrs2](https://discuss.px4.io/letter_avatar_proxy/v4/letter/t/a4c791/32.png) [@tbrs2](https://discuss.px4.io/u/tbrs2)\ **Post date:** [November 5, 2018, 5:53pm UTC](https://discuss.px4.io/t/precision-landing-in-sitl-issue/8369/3 "2018-11-05T17:53:19Z")
Ah, okay, thanks a lot. I did get it working before without anything added to the config files, but whenever I try to precision land with command mode auto:precland it just times out, even though I’m right over the virtual IR lock. The MAV\_CMD\_NAV\_LAND mentioned in the documentation doesn’t seem to exist anymore, but I don’t think it’s to do with that. I’ve tried playing around with the PLD parameters but nothing seems to stop the timeout issue. ---
**Author:** ![tbrs2](https://discuss.px4.io/letter_avatar_proxy/v4/letter/t/a4c791/32.png) [@tbrs2](https://discuss.px4.io/u/tbrs2)\ **Post date:** [November 5, 2018, 6:43pm UTC](https://discuss.px4.io/t/precision-landing-in-sitl-issue/8369/4 "2018-11-05T18:43:32Z")
Given this similar issue from July [https://github.com/PX4/Firmware/issues/9904](https://github.com/PX4/Firmware/issues/9904) I’m wondering if this is a persisting issue. Has anyone managed to get IRlock with SITL working correctly? I’d also be interested to hear about anyone who’s used IRlock with a Pixhawk 4. Thanks Tom ---
**Author:** ![Nicolas](https://discuss.px4.io/user_avatar/discuss.px4.io/nicolas/32/4467_2.png) [@Nicolas](https://discuss.px4.io/u/Nicolas)\ **Post date:** [November 5, 2018, 7:12pm UTC](https://discuss.px4.io/t/precision-landing-in-sitl-issue/8369/5 "2018-11-05T19:12:30Z")
We are using irlocks in hardware (with a Pixracer) and in SITL. We have no problems. It should be noted though, that our firmware is based on PX4 v1.7.4 currently. Perhaps it has been broken since. You could give that version a try. How does it time out exactly? Can you share a log? ---
**Author:** ![tbrs2](https://discuss.px4.io/letter_avatar_proxy/v4/letter/t/a4c791/32.png) [@tbrs2](https://discuss.px4.io/u/tbrs2)\ **Post date:** [November 5, 2018, 7:36pm UTC](https://discuss.px4.io/t/precision-landing-in-sitl-issue/8369/6 "2018-11-05T19:36:04Z")
It goes to the set altitude for initiating the precision landing, waits the specified time, then can’t locate the IR lock in the specified time, so times out and initiates normal landing instead. I’ve tried setting the minimum horizontal distance threshold as high as possible (10m), but it doesn’t solve it. I’m not at work now so don’t have the exact logs or a logfile. I can get them tomorrow. It’s reassuring to know that you’ve got it working with one version of the software though! I’ll see if I can test it with 1.7.4. Thanks a lot Nicolas. Tom ---
**Author:** ![tbrs2](https://discuss.px4.io/letter_avatar_proxy/v4/letter/t/a4c791/32.png) [@tbrs2](https://discuss.px4.io/u/tbrs2)\ **Post date:** [November 6, 2018, 10:34am UTC](https://discuss.px4.io/t/precision-landing-in-sitl-issue/8369/7 "2018-11-06T10:34:06Z")
So here’s the console output I get when building the firmware, taking off, and attempting a precision land. Yesterday, I hadn’t noticed the message “[Wrn] [msgs.cc:1808] Conversion of sensor type[logical\_camera] not suppported.” I guess this is an issue with interfacing with Gazebo, but either way I’m not sure how to fix it. [Msg] Waiting for master. [Msg] Connected to gazebo master @ [http://127.0.0.1:11345](http://127.0.0.1:11345) [Msg] Publicized address: 10.200.13.64 [Wrn] [msgs.cc:1808] Conversion of sensor type[logical\_camera] not suppported. [Dbg] [gazebo\_mavlink\_interface.cpp:138] \ not found for channel[0] no joint control will be performed for this channel. [Dbg] [gazebo\_mavlink\_interface.cpp:138] \ not found for channel[1] no joint control will be performed for this channel. [Dbg] [gazebo\_mavlink\_interface.cpp:138] \ not found for channel[2] no joint control will be performed for this channel. [Dbg] [gazebo\_mavlink\_interface.cpp:138] \ not found for channel[3] no joint control will be performed for this channel. [Wrn] [gazebo\_mavlink\_interface.cpp:127] joint [zephyr\_delta\_wing::propeller\_joint] not found for channel[4] no joint control for this channel. [Wrn] [gazebo\_mavlink\_interface.cpp:127] joint [zephyr\_delta\_wing::flap\_left\_joint] not found for channel[5] no joint control for this channel. [Wrn] [gazebo\_mavlink\_interface.cpp:127] joint [zephyr\_delta\_wing::flap\_right\_joint] not found for channel[6] no joint control for this channel. [Dbg] [gazebo\_mavlink\_interface.cpp:138] \ not found for channel[7] no joint control will be performed for this channel. [Msg] Using MAVLink protocol v2.0 [Wrn] [RaySensor.cc:359] ranges not constructed yet (zero sized) SITL COMMAND: /home/tom/px4/px4\_toolchain/src/Firmware/build/posix\_sitl\_default/bin/px4 /home/tom/px4/px4\_toolchain/src/Firmware/ROMFS/px4fmu\_common -s etc/init.d-posix/rcS -t /home/tom/px4/px4\_toolchain/src/Firmware/test\_data INFO [Unknown] Creating symlink /home/tom/px4/px4\_toolchain/src/Firmware/ROMFS/px4fmu\_common -\> /home/tom/px4/px4\_toolchain/src/Firmware/build/posix\_sitl\_default/tmp/rootfs/etc 107 WARNING: setRealtimeSched failed (not run as root?) * * * | \_\_\_ \ \ \ / / / | | |_/ / \ V / / /| | | \_\_/ / \ / /_| | | | / /^\ \ \_\_\_ | \_| / / |\_/ px4 starting. INFO [Unknown] Calling startup script: /bin/sh etc/init.d-posix/rcS 0 SYS\_AUTOSTART: curr: 0 -\> new: 1011 BAT\_N\_CELLS: curr: 0 -\> new: 3 CAL\_ACC0\_ID: curr: 0 -\> new: 1376264 CAL\_ACC1\_ID: curr: 0 -\> new: 1310728 CAL\_ACC\_PRIME: curr: 0 -\> new: 1376264 CAL\_GYRO0\_ID: curr: 0 -\> new: 2293768 CAL\_GYRO\_PRIME: curr: 0 -\> new: 2293768 CAL\_MAG0\_ID: curr: 0 -\> new: 196616 CAL\_MAG\_PRIME: curr: 0 -\> new: 196616 COM\_DISARM\_LAND: curr: -1.0000 -\> new: 0.1000 COM\_OBL\_ACT: curr: 0 -\> new: 2 COM\_OF\_LOSS\_T: curr: 0.0000 -\> new: 5.0000 COM\_RC\_IN\_MODE: curr: 0 -\> new: 1 EKF2\_ANGERR\_INIT: curr: 0.1000 -\> new: 0.0100 EKF2\_GBIAS\_INIT: curr: 0.1000 -\> new: 0.0100 EKF2\_MAG\_TYPE: curr: 0 -\> new: 1 MC\_PITCH\_P: curr: 6.5000 -\> new: 6.0000 MC\_PITCHRATE\_P: curr: 0.1500 -\> new: 0.2000 MC\_ROLL\_P: curr: 6.5000 -\> new: 6.0000 MC\_ROLLRATE\_P: curr: 0.1500 -\> new: 0.2000 MPC\_HOLD\_MAX\_Z: curr: 0.6000 -\> new: 2.0000 MPC\_Z\_VEL\_I: curr: 0.0200 -\> new: 0.1500 MPC\_Z\_VEL\_P: curr: 0.2000 -\> new: 0.6000 NAV\_ACC\_RAD: curr: 10.0000 -\> new: 2.0000 NAV\_DLL\_ACT: curr: 0 -\> new: 2 RTL\_DESCEND\_ALT: curr: 30.0000 -\> new: 5.0000 RTL\_LAND\_DELAY: curr: -1.0000 -\> new: 5.0000 RTL\_RETURN\_ALT: curr: 60.0000 -\> new: 30.0000 SDLOG\_DIRS\_MAX: curr: 0 -\> new: 7 SENS\_BOARD\_X\_OFF: curr: 0.0000 -\> new: 0.0000 SENS\_DPRES\_OFF: curr: 0.0000 -\> new: 0.0010 - RTL\_DESCEND\_ALT: curr: 5.0000 -\> new: 10.0000 - RTL\_LAND\_DELAY: curr: 5.0000 -\> new: 0.0000 PWM\_MAX: curr: 2000 -\> new: 1950 PWM\_MIN: curr: 1000 -\> new: 1075 LTEST\_MODE: curr: 0 -\> new: 1 PLD\_HACC\_RAD: curr: 0.2000 -\> new: 0.1000 INFO [dataman] Unknown restart, data manager file ‘./dataman’ size is 11405132 bytes INFO [simulator] Waiting for initial data on UDP port 14560. Please start the flight simulator to proceed… Gazebo multi-robot simulator, version 7.14.0 Copyright © 2012 Open Source Robotics Foundation. Released under the Apache 2 License. [http://gazebosim.org](http://gazebosim.org) [Msg] Waiting for master. [Msg] Connected to gazebo master @ [http://127.0.0.1:11345](http://127.0.0.1:11345) [Msg] Publicized address: 10.200.13.64 [Wrn] [Event.cc:87] Warning: Deleteing a connection right after creation. Make sure to save the ConnectionPtr from a Connect call INFO [simulator] Got initial simulation data, running sim… [Wrn] [msgs.cc:1808] Conversion of sensor type[logical\_camera] not suppported. INFO [init] Mixer: etc/mixers/quad\_w.main.mix on /dev/pwm\_output0 INFO [ekf2] Found range finder with instance 0 INFO [mavlink] mode: Normal, data rate: 4000000 B/s on udp port 14570 remote port 14550 INFO [mavlink] mode: Onboard, data rate: 4000000 B/s on udp port 14580 remote port 14540 INFO [logger] logger started (mode=all) INFO [logger] Start file log INFO [logger] Opened log file: ./log/2018-11-06/10\_29\_34.ulg INFO [mavlink] MAVLink only on localhost (set param MAV\_BROADCAST = 1 to enable network) INFO [Unknown] Startup script returned successfully **pxh\> [Wrn] [msgs.cc:1808] Conversion of sensor type[logical\_camera] not suppported.** INFO [mavlink] partner IP: 127.0.0.1 INFO [ecl/EKF] EKF aligned, (pressure height, IMU buf: 22, OBS buf: 14) INFO [ecl/EKF] EKF GPS checks passed (WGS-84 origin set) INFO [ecl/EKF] EKF commencing GPS fusion [Wrn] [Publisher.cc:141] Queue limit reached for topic /gazebo/default/iris\_irlock/imu, deleting message. This warning is printed only once. **pxh\> commander takeoff** **pxh\> INFO [commander] Takeoff detected** [Wrn] [Publisher.cc:141] Queue limit reached for topic /gazebo/default/iris\_irlock/motor\_speed/0, deleting message. This warning is printed only once. pxh\> commander mode auto:[Wrn] [Publisher.cc:141] Queue limit reached for topic /gazebo/default/iris\_irlock/gazebo/command/motor\_speed, deleting message. This warning is printed only once. pxh\> commander mode auto:precland pxh\> WARN [navigator] Resetting landing position to current position INFO [navigator] Climbing to search altitude. [Wrn] [Publisher.cc:141] Queue limit reached for topic /gazebo/default/iris\_irlock/motor\_speed/1, deleting message. This warning is printed only once. **WARN [navigator] Search timed out** **WARN [navigator] Falling back to normal land.** [Wrn] [Publisher.cc:141] Queue limit reached for topic /gazebo/default/iris\_irlock/motor\_speed/2, deleting message. This warning is printed only once. INFO [commander] Landing detected INFO [logger] closed logfile, bytes written: 3831392 ---
**Author:** ![Nicolas](https://discuss.px4.io/user_avatar/discuss.px4.io/nicolas/32/4467_2.png) [@Nicolas](https://discuss.px4.io/u/Nicolas)\ **Post date:** [November 9, 2018, 2:17am UTC](https://discuss.px4.io/t/precision-landing-in-sitl-issue/8369/8 "2018-11-09T02:17:46Z")
Yes it looks like something is broken with the Gazebo simulation. The message you mention is not printed when I run it. I see that I have Gazebo 7.0.0 installed. It’s possible that Gazebo’s API has changed since and the logical camera is not supported the way we use it anymore. ---
**Author:** ![ebabyak](https://discuss.px4.io/letter_avatar_proxy/v4/letter/e/e8c25b/32.png) [@ebabyak](https://discuss.px4.io/u/ebabyak)\ **Post date:** [November 14, 2018, 6:02pm UTC](https://discuss.px4.io/t/precision-landing-in-sitl-issue/8369/9 "2018-11-14T18:02:59Z")
I’m having a similar issue with Precision Landing in SITL. I attempted various combinations of Firmware and Gazebo versions without luck. @tbrs did you identify the issue? Thanks! ---
**Author:** ![tbrs2](https://discuss.px4.io/letter_avatar_proxy/v4/letter/t/a4c791/32.png) [@tbrs2](https://discuss.px4.io/u/tbrs2)\ **Post date:** [November 14, 2018, 7:25pm UTC](https://discuss.px4.io/t/precision-landing-in-sitl-issue/8369/10 "2018-11-14T19:25:57Z")
@ebabyak No I never figured it out. I had meant to try using the same version of firmware that Nicolas is running but got sidetracked. Given it’s not just me experiencing this, I’m guessing there is a genuine problem caused by an update to Gazebo as Nicolas describes. I was doing the testing to assess the precision landing feature for myself before buying all the necessary sensors. If it’s just a Gazebo issue then hopefully it’s still fine in the real world. I’ll try and find the time to have another go at solving this. ---
**Author:** ![ebabyak](https://discuss.px4.io/letter_avatar_proxy/v4/letter/e/e8c25b/32.png) [@ebabyak](https://discuss.px4.io/u/ebabyak)\ **Post date:** [November 15, 2018, 4:58pm UTC](https://discuss.px4.io/t/precision-landing-in-sitl-issue/8369/11 "2018-11-15T16:58:15Z")
@tbrs2 @Nicolas - After a little digging I discovered landing\_target\_estimator wasn’t started. I started it from the px4 shell using: landing\_target\_estimator start and can now do successful precision lands. @tbrs2 I think the logical\_camera message you are getting from Gazebo isn’t critical. ---
**Author:** ![tbrs2](https://discuss.px4.io/letter_avatar_proxy/v4/letter/t/a4c791/32.png) [@tbrs2](https://discuss.px4.io/u/tbrs2)\ **Post date:** [November 15, 2018, 5:30pm UTC](https://discuss.px4.io/t/precision-landing-in-sitl-issue/8369/12 "2018-11-15T17:30:22Z")
That worked for me too. Well done ebabyak, and thanks very much! ---
**Author:** ![Nicolas](https://discuss.px4.io/user_avatar/discuss.px4.io/nicolas/32/4467_2.png) [@Nicolas](https://discuss.px4.io/u/Nicolas)\ **Post date:** [November 20, 2018, 11:06am UTC](https://discuss.px4.io/t/precision-landing-in-sitl-issue/8369/13 "2018-11-20T11:06:29Z")
> [@ebabyak](#): > > After a little digging I discovered landing\_target\_estimator wasn’t started This was likely caused by > @bkueng I’m not yet familiar with the new SITL init scripts. Where should airframe-/simulation-specific applications be started? ---
**Author:** ![bkueng](https://discuss.px4.io/letter_avatar_proxy/v4/letter/b/2bfe46/32.png) [@bkueng](https://discuss.px4.io/u/bkueng)\ **Post date:** [November 20, 2018, 12:24pm UTC](https://discuss.px4.io/t/precision-landing-in-sitl-issue/8369/14 "2018-11-20T12:24:05Z")
> [@Nicolas](#): > > @bkueng I’m not yet familiar with the new SITL init scripts. Where should airframe-/simulation-specific applications be started? I’d add it directly to the vehicle’s startup script: [https://github.com/PX4/Firmware/blob/master/ROMFS/px4fmu\_common/init.d-posix/1011\_iris\_irlock#L15](https://github.com/PX4/Firmware/blob/master/ROMFS/px4fmu_common/init.d-posix/1011_iris_irlock#L15). ---
**Author:** ![Nicolas](https://discuss.px4.io/user_avatar/discuss.px4.io/nicolas/32/4467_2.png) [@Nicolas](https://discuss.px4.io/u/Nicolas)\ **Post date:** [November 20, 2018, 12:38pm UTC](https://discuss.px4.io/t/precision-landing-in-sitl-issue/8369/15 "2018-11-20T12:38:42Z")
@ebabyak can you confirm that adding `landing_target_estimator start` as described by @bkueng gives you a functioning system without further modifications? And if so, would you mind opening a PR with the change? ---
**Author:** ![ebabyak](https://discuss.px4.io/letter_avatar_proxy/v4/letter/e/e8c25b/32.png) [@ebabyak](https://discuss.px4.io/u/ebabyak)\ **Post date:** [November 20, 2018, 3:24pm UTC](https://discuss.px4.io/t/precision-landing-in-sitl-issue/8369/16 "2018-11-20T15:24:06Z")
@Nicolas This worked for me, created PR at [https://github.com/PX4/Firmware/pull/10882](https://github.com/PX4/Firmware/pull/10882)