The incident happened at around 1am on Sunday 31 October 2021 in an alleyway between Alma Road and Berridge Road.
It is reported the suspect punched the woman, who is in her 20s, before he raped her.
The suspect is believed to be white, of heavy build, balding and wearing a dark grey hooded top and light grey trousers.
Detective Chief Inspector Neil Kimber of Kent Police said: ‘We are making a number of enquiries and have already seized a significant amount of CCTV and gathered forensic evidence. Stranger incidents of this nature are rare and we are committed to ensuring a thorough investigation whilst supporting the victim throughout the process.
‘I would ask people who were in the area in the early hours of Sunday 31 October to review any dashcam, doorbell or CCTV footage and contact us if they have captured images that will assist us in our enquiries. Alternatively, if anyone witnessed anything suspicious or has any information about the incident, please call the witness appeal line.’
If anyone has information, please contact Kent Police on 01795 419119, quoting reference number 31-0112.
You can also contact Crimestoppers anonymously on 0800 555111, or by using the online form on their website.