IR detector system, biasing of photo diode

Hi
I am working on an IR detector that will guide a robot into a docking station.
A IR transmitter on the docking station transmits a beam, and 2 IR detectors on the robot detects the beam and lets the robot navigate towards the target. The working distance is a couple of meters.
I need it to be insensitive to ambient light/sunlight.
The IR detectors are placed in a tube, to narrow in the beam angle and to avoid sunlight (since it is seldom the sun is actually that low in the horizon)
The IR transmitter will be modulated with 10kHz (TBD) frequency, low duty cycle. Low duty cycle to be able to drive the LED with high current, frequency modulated so that the receiver can ignore the effect of daylight (DC)
If the LED on the docking station has higher radiant intensity at the point of the robot (2 meters away) than possible IR from sunlight, then that would be perfect.
Example of transmitter:
https://www.vishay.com/docs/83398/vsmy2850.pdf
Has up to 1000mW/sr. Seems my basic calculation for a 15 degree beam, shows less than 10nW/m2, while sunlight has 1W/m2. So driving a beam that has higher output than sunlight seems unlikely.
I would use a IR phototransistor at 850nm, something like this:
https://www.ttelectronics.com/TTElectronics/media/ProductFiles/Datasheet/OP505-506-535-705.pdf
Or a photo diode:
https://docs.rs-online.com/9f58/0900766b816d8a09.pdf
Fed from reverse 3.3V and into a transimpedance amplifier to boost the signal with bandpass filter.
One can get digital IR detector used in a remote control systems:
https://www.vishay.com/docs/82491/tsop382.pdf
It has AGC, but digital output. I need analog output to be able to zero in on the transmitter beam.
I have been looking for IR detectors that has the analog output, not just the digital, but have not found any.
If the photodiode detector is subjected to sunlight, I am guessing I would need very high gain on the 10kHz modulation frequency to pick up the burried signal in the DC from sunlight.
How do I best bias the photo diode for optimum detection of the 10kHz signal while being immune to the ambient sunlight?
I have chosen 850nm which seems to be a good wavelength. The spectrum at sea level has some dips due to water absorption.
https://sciencetech-inc.com/web/image/49169/Spectrum%20with_out%20absorption.png
Seems like 750nm would be better, since then the IR from the sun is lower, but does reduced the effective range of the system during fog/rain. Probably that's why these system do not use 750nm
Other considerations?