Last year, he pleaded guilty at the Old Bailey to plotting an attack in the UK and funding Isis abroad.
Judge Nicholas Hilliard QC jailed Ludlow for life with a minimum term of 15 years for the attack plan, with seven years to run concurrently for funding.
The judge said Ludlow had been engaged in preparations for a "spectacular" multi-casualty attack "with the intention of causing death or terror".
He told the defendant: "Your commitment at the time we are concerned with to violent extremism ran very deep and for some time.
"There could be no other explanation for your preparing to kill innocent people in a vehicle attack for ideological reasons."
Hilliard rejected the suggestion Ludlow had been coerced by an Isis supporter in the Philippines, saying the defendant was "nobody's fool".
He added: "I do not regard you as suggestible or easily taken advantage of. You were well able to resist the Prevent programme."
The note, in full:
"Oxford Street - long road with no bollards or barriers preventing a can mounting the pavement.
"Busiest time is between 11am-12pm with Saturday being the busisest day.
"Wolf should either use a ram attack or use ... on the truck to maximise death ... it is a busy street it is ideal for an attack.
"It is expected nearly 100 could be killed in the attack."
A handwritten letter found in a bin detailing potential targets in London.
The court heard how Ludlow, from Rochester in Kent, first came to the attention of police in 2010 when he attended a demonstration led by radical preacher Anjem Choudary and his banned Al-Muhajiroun (ALM) group.
When he was arrested in 2015, Isis material was found on Ludlow's electronic devices but no further action was taken.
In January 2018, he bought a ticket to fly to the Philippines on February 3 but was stopped at the airport and had his passport seized.
Having set up a PayPal account and a fake Facebook site called Antique Collections, he sent money to an Isis supporter, Abu Yaqeen, in the Philippines.
Ludlow also turned his attention to launching an attack in Britain, with encouragement from Yaqeen, the court heard.
He visited an internet cafe in Vauxhall Bridge Road in central London where he searched online for shopping centres, Oxford Street and the Isis flag.
On April 13 Ludlow's mobile phone was retrieved from a storm drain and found to have videos of the defendant swearing allegiance to Isis and evidence of "hostile reconnaissance".
When Ludlow was arrested by counter-terrorism police he refused to explain himself in interview.
Following his guilty plea, Ludlow told how he rejected an MI5 advance in March 2017 but agreed to engage with the Prevent programme.
He became "bitter" and "heartbroken" when he was barred from going to the Philippines, he said: "I felt that I was trapped like an animal unable to escape its cage."
