Pool alarm with wireless remote alarm, how to integrate with it?
Looking at the manual, this is FCC certified. That means you can find out a lot about it.

I went to here and searched by the parent company's name, MG International, bringing up 4 applications. One of these is the Sensor Espio.

From there, I can see it works on 433.92 MHz - this is probably the most common band for wireless devices. The schematic is available - it uses a TI CC1100. The operational description says it uses OOK with a 16 bit security word and 8 bit command word.

Most of these 433MHz devices use fairly simple Manchester encoding, sometimes using infra-red remote protocols over RF. I've not used a CC1100 before, but have used a CC1110, which is fundamentally the same. They have a lot of fancy features for FSK and MSK, but are quite basic and hard work for ASK/OOK. I think this means that the protocol is essentially free choice, but most of these will be a long preamble of 1010101010 or similar, followed by the security/ID and then command word repeated several times.

You can use any of the simple 433MHz receivers to pick these raw signals up, but then you will need to use a microcontroller or similar to wait for the preamble and listen to the words. The website JeeLabs has a large number of tools to help you connect a 433Mhz receiver to an Arduino and decode it.

By logging - do you mean simply recording? Any microcontroller can do this. Or do you mean alerting you via SMS or email?